# Will disc brakes for road bikes ever catch on?



## Waspinator (Jul 5, 2013)

I can see their benefit for offroading, but for road?


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## MB1 (Jan 27, 2004)

Already have.

HTH


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## SundayNiagara (Apr 17, 2014)

As a n00b to biking, I had considered discs, but ultimately decided against them because, They are not quite ready for prime time and the technology is still evolving.


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## ericm979 (Jun 26, 2005)

I've seen some riding around (there's a lot of road cyclists in the area). A number in the last double century I did. None in road races (they are not illegal in USAC amateur road racing).


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## Marc (Jan 23, 2005)

MB1 said:


> Already have.
> 
> HTH


Ish. But I'd barely count 1-in-10 or less (guesstimate) retail road bikes as even being capable of mounting them, never mind being sold with them, as having caught on.


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## tlg (May 11, 2011)

Waspinator said:


> Will disc brakes for road bikes ever catch on?


Yes, it's inevitable. Whether it "catches on" or is forced on by manufacturers, it's going to eventually happen.

I just looked at Trek & Specialized websites. Neither offer a MTB with rim brakes on a bike over $600. WTF. Most people who MTB do not need disc brakes. Yet that's all they are offered. 

I predict the exact same to happen with road bikes.


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## penn_rider (Jul 11, 2009)

tlg said:


> Yes, it's inevitable. Whether it "catches on" or is forced on by manufacturers, it's going to eventually happen.
> 
> I just looked at Trek & Specialized websites. Neither offer a MTB with rim brakes on a bike over $600. WTF. Most people who MTB do not need disc brakes. Yet that's all they are offered.
> 
> I predict the exact same to happen with road bikes.


Totally agree.


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## JetSpeed (Nov 18, 2002)

No. It's a fad like speckled bar tape. 

Never have I wished I could stop faster on a roadbike.


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## r1lee (Jul 22, 2012)

personally i think they will eventually switch over to disc, even though its not needed.

For 2015, Giant is adding disc brakes to the entire Defy line. To go along with the frame redesign.


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## pdh777 (Oct 7, 2005)

Maybe a long while before it catches on in road racing - very slow for wheel changes.


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## obed (Jan 12, 2014)

I think it will eventually be forced by the mfg.


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## Roland44 (Mar 21, 2013)

obed said:


> I think it will eventually be forced by the mfg.


Hopefully!


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## Pirx (Aug 9, 2009)

No. .


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## TJay74 (Sep 9, 2012)

tlg said:


> Yes, it's inevitable. Whether it "catches on" or is forced on by manufacturers, it's going to eventually happen.
> 
> I just looked at Trek & Specialized websites. Neither offer a MTB with rim brakes on a bike over $600. WTF. Most people who MTB do not need disc brakes. Yet that's all they are offered.
> 
> I predict the exact same to happen with road bikes.



Why would you want rim brakes??? Less stopping power than disc, horrible performance when wet, weigh more than disc brakes (not only in the brakes but also in extra material in the rim as well).

Hands down I would take disc brakes over rim if the option was there.


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## MMsRepBike (Apr 1, 2014)

They will. Why? Carbon wheels.

Seems everyone wants carbon wheels and let's be honest, they suck at braking down mountains and such. Plus who wants to put that much stress on carbon by rim braking on it?

Carbon wheels and disc brakes are like best friends. Together they will take over everything.

I'm the guy that will be still be on his rim brakes though ten years down the road.


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## exracer (Jun 6, 2005)

TJay74 said:


> Why would you want rim brakes??? Less stopping power than disc, horrible performance when wet, weigh more than disc brakes (not only in the brakes but also in extra material in the rim as well).
> 
> Hands down I would take disc brakes over rim if the option was there.


Why would I want them? I can already unicycle on the front wheel with rim brakes if I brake hard enough. There is more of a performance advantage when using carbon clinchers. I don't ride on carbon wheels every single day, so the minimal braking advantage I would get for 90% of my riding isn't worth making the switch.


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## Trek_5200 (Apr 21, 2013)

Pirx said:


> No. .


Those that are most into electronics and are apt to purchase or own eps systems will be most likely to go disc, but the benefit is mostly for off road or wet weather, and they go contrary to the desire to reduce road bike weight.


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## Srode (Aug 19, 2012)

They're good in a few applications on the road IMHO, but not enough to make it worthwhile for more than 5% of the bikes purchased. That's with the current technology. If they were lighter and slightly improved dry braking (for mechanical brakes) the would be a good choice for many. Right now the only advantage is wet riding.


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## Marc (Jan 23, 2005)

Srode said:


> They're good in a few applications on the road IMHO, but not enough to make it worthwhile for more than 5% of the bikes purchased. That's with the current technology. If they were lighter and slightly improved dry braking (for mechanical brakes) the would be a good choice for many. Right now the only advantage is wet riding.


Even then...things like brake steering, hot calipers heating up hub bearings inducing wear/tear, wheels pulling out of dropouts, and fussy setup/maintenance are things that will probably never go away.

Aside from CF rims...which most people do not have...and people like racers who do have them want quick change wheels, which disc brakes aren't near as fast AFAIK and given the non-standard state of disc brakes kiss neutral service wheels goodbye. Solution in search of a problem for most people.


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## grandsalmon (Jan 18, 2009)

Discs to MTBs was just a phenomenal gift, powerful but they can modulate pretty well also.

Soon they ended up on a few commuters of mine, some lightweight rigs, running 25c tires on up. 
Also carbon hoops for rim braking on the road bike can be a worry no more. 

On top of all that -I love all-day rides in the mountains, let's say- and inclement weather nary affects my braking. Mutually the appearance of thru-axles if offered, helps the whole front end. True, I'm no racer needing whip-wheel changes.
The increased performances are notable, more for some, but here to stay.

(from above: fear of baking your hub bearings hasta be a myth)


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## Bill2 (Oct 14, 2007)

I think they will eventually dominate the market, just like on cars. In the wet they are like night and day.


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## SauronHimself (Nov 21, 2012)

I suppose I'll switch to disc brake rims when the dominate the market and Black Prince pads run $100/set.


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## jlandry (Jan 12, 2007)

pdh777 said:


> Maybe a long while before it catches on in road racing - very slow for wheel changes.


I think this is the main concern.


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## Marc (Jan 23, 2005)

grandsalmon said:


> Discs to MTBs was just a phenomenal gift, powerful but they can modulate pretty well also.
> 
> Soon they ended up on a few commuters of mine, some lightweight rigs, running 25c tires on up.
> Also carbon hoops for rim braking on the road bike can be a worry no more.
> ...



You really think so? When there exist mountain descents that can cause a bike rim to overheat enough from rim-braking to cause tire blowouts or a carbon wheel to come apart from friction on a breaking surface 622mm in diameter...you question whether or not a disc-brake that is a mere 1/5th the size in diameter (and therefore circumference) will get hot enough to screw with the temperature of your hub bearings?

Even in normal MTBing applications, it took a while for manufacturers like Shimano (only) the first generation of discs to catch on to the problem of disc heat and finally start putting heat sinks on the calipers...as before that pads would overheat and melt and/or fluid could boil.


Those ****ers get hot, don't be mistaken. The longer you need to brake the hotter they get. All your momentum from your 60-100KG gets turned into waste heat on a tiny disc of metal 140-200mm in diameter in order to stop you. A rim-brake is the same thing as a disc in function, but a rim brake surface is 5x as big and therefore much better at dealing with heat.


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## crossracer (Jun 21, 2004)

Where I ride disks make no sense. But then again, there are places that they make perfect sense. 

I think a bigger improvement that is quietly coming is thru axles for for road bikes. That would really stiffen up the ride and make a noticeable improvement. But that's just my guess and opinion. 

Bill


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## tlg (May 11, 2011)

TJay74 said:


> Why would you want rim brakes??? Less stopping power than disc, horrible performance when wet, weigh more than disc brakes (not only in the brakes but also in extra material in the rim as well).
> 
> Hands down I would take disc brakes over rim if the option was there.


I run XTR V's and Avid Single digits on one of my MTB's. I could easily put myself OTB if I wanted to. Stopping power is definitely not the issue. Most people don't need that stopping power while putzing down some singletrack.

A lot of people don't ride when it's wet. So they don't need great performance when wet.

My V's are lighter than disc calipers (not even including rotors). And so what if they were a few grams heavier. Most people are riding on 28-32lb MTB's. Do you think they're going to benefit from 100g?

I've got disc's too. They're nice. But for most of my riding they're no better than my V's.


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## Notvintage (May 19, 2013)

I think for different markets it may, but you have the light weight players who have 800 gram frames and Ti-spindles and stuff. I can't see say Contador climbing on a silly disc bike. The frames are heavier, the wheels are heavier, the brakes are heavier. . For downhill MTB, they make sense to me, but not on a proper road bike. I see them on "touring road bikes" and hybrids as well.


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## woodys737 (Dec 31, 2005)

I think they will catch on if the industry wants them to independent of necessity. For example, I use 10 cog cassettes, carbon bars and Rotor Q rings. None of those are really necessary but for some reason here I am riding them. I'm 99% sure I'd be in the same place performance wise if I was still riding my 80's Bianchi compared to my "modern" ride. For some reason I've done a good job convincing myself all these marginal gains really make a noticeable difference. In reality, I think the bike system feels different more than performs differently. jmo

The caliper/rim brake is basically a huge disc brake system. Stopping power is not the issue so modulation must be at the tip of the spear for the marketing departments. I think modulation is better but the reality is it's not necessary and we'll just end up paying more for forced marketing evolution. I'm not saying it's right or wrong just capitalism I guess.


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## GRAVELBIKE (Sep 16, 2011)

For wet-weather commuting, I _really_ like discs. I've ridden disc-equipped bikes in rain and snow, and braking has been excellent. For bikes with tires less than, say, 35mm wide, I prefer rim brakes, though. My go-fast (where 'fast' is open to interpretation) is equipped with TRP RG957 calipers and SRAM Force 22 levers, and the combination is sublime with 28mm road tires (which actually measure 30.5mm on 25mm rims).


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## Ryder's (Oct 18, 2013)

Sliced bread
Silent movies
Talkies
Black and white TV
Colored TV
Telephone switchboards
Rotary phones
Cordless phones
Manned Flight
Jet planes
Space flight
Cloning
Organ transplants
Cellular phone
Commodore Vic 64
PC's 
Laptops
Tablets
Friction shifters
Indexed shifting
Tubeless technology
Disc brakes on road bikes?
You must be dreaming.


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## pmf (Feb 23, 2004)

Ryder's said:


> Sliced bread
> Silent movies
> Talkies
> Black and white TV
> ...


You forgot compact geometry


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## bayAreaDude (Apr 13, 2012)

Ryder's said:


> Sliced bread
> Silent movies
> Talkies
> Black and white TV
> ...


Sliced bread sucks compared to bread from a real bakery. Different doesn't always mean an advancement, particularly if the differences don't offer any advantages to the current solution. I don't want any more stopping power, don't ride in the wet often enough, and have no plans to ride carbon wheels.


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## Ryder's (Oct 18, 2013)

Sliced bread sucks compared to bread from a bakery ? How about fresh baked bread that's sliced at the bakery ? No one is forcing you to ride disc brakes or to eat sliced bread. But they have both caught on and are here to stay.


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## TricrossRich (Mar 26, 2014)

I have them on my Tricross and quite frankly, I love them... IMO, it isn't that they offer more stopping power over a rim brake, its that there is greater control of modulation of the brakes. I also think they have some great advantages in adverse riding conditions like wet, muddy, etc... 

Do I think they'll catch on? that all depends on what the UCI does.... if the UCI makes it legal, more manufacturers will put them on bikes and more pros will ride them (because they either want to or they're told to by their sponsors) and what the pros use, the public buys, simple as that.. What wins on Sunday, sells on Monday... that's how its always been, how its always gonna be.


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## Jay Strongbow (May 8, 2010)

Ryder's said:


> Sliced bread sucks compared to bread from a bakery ? How about fresh baked bread that's sliced at the bakery ? No one is forcing you to ride disc brakes or to eat sliced bread. But they have both caught on and are here to stay.


I've never, ever, seen disc brakes at a road race or group ride. Maybe it's different where you live but I think you may need to revisit your definition of "caught on" with respect to road riding.


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## bayAreaDude (Apr 13, 2012)

Ryder's said:


> Sliced bread sucks compared to bread from a bakery ? How about fresh baked bread that's sliced at the bakery ? No one is forcing you to ride disc brakes or to eat sliced bread. But they have both caught on and are here to stay.


Your list seemed to be a pair of what looked like advancements that made the previous tech obsolete. I don't think that applies in this case because I think these are just different products for people who have different needs.


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## Ryder's (Oct 18, 2013)

bayAreaDude said:


> Your list seemed to be a pair of what looked like advancements that made the previous tech obsolete. I don't think that applies in this case because I think these are just different products for people who have different needs.


I guess my list could be viewed like that, but it was more an observation of new technologies that were panned when they intially arrived in the market place. I live in NW NJ and I haven't seen any road bikes sporting disc brakes yet, though the technology is still in its infancy ( road disc brakes) and I'd feel confident in saying that 3-5 years from now it they will become more commonplace and accepted. My primary road bike is equipped with Dura Ace brakes and they are stellar a d suit my needs perfectly. The work flawless in all conditions. Granted here NJ we're hard pressed to average more than 125' of gain/descent per mile.


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## Marc (Jan 23, 2005)

Ryder's said:


> I guess my list could be viewed like that, but it was more an observation of new technologies that were panned when they intially arrived in the market place. I live in NW NJ and I haven't seen any road bikes sporting disc brakes yet, though the technology is still in its infancy ( road disc brakes) and *I'd feel confident in saying that 3-5 years from now it they will become more commonplace and accepted*. My primary road bike is equipped with Dura Ace brakes and they are stellar a d suit my needs perfectly. The work flawless in all conditions. Granted here NJ we're hard pressed to average more than 125' of gain/descent per mile.


Who knows. 

Non-round chainrings have never really caught on throughout their dozens of iterations over the last 100+ years with every new one claiming to fix all the fallacies of the old. The bike saddle hasn't changed much at all despite all manner of "improved" designs because the standard saddle shape manages to just work. Roadie bikes nowadays almost never fit tires larger than 25-28mm and almost never have fender mounts...even though given the riding most normal people do, both of those are design mistakes/short comings.

Given the general attitude towards disc brakes being positive maybe they'll get a quicker green-light, like electronic shifting. But that has taken what? 5 years to become fairly common on top tier?


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## duriel (Oct 10, 2013)

NO! enie, minie, minie, moe, & curly


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## velodog (Sep 26, 2007)

They won't catch on in my house. But that ain't gonna stop the manufacturers from forcing them onto the bike buying public.

I guess that they are a good thing if a person is so ham fisted and lacking in finesse that they cannot modulate a set of rim brakes. They are kinda like ABS brakes on automobiles, where all a person has to know how to do is mash their foot into the floor boards, no finesse needed.

No need to develop a skill set when someone else can design it into the appliance for you.


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## Special Eyes (Feb 2, 2011)

I can't wait to have them on my next bike. As for the UCI approval and limited wheel change options in a race, do you know what a tiny percentage of bikes, even high end ones, ever get near a race? The amateur, casual, weekend warrior, personal performance sector is huge. That's why nearly all big name manufacturers and even Italian boutique frame builders are offering them now. Shimano and other component mfg'ers are not at all concerned with any of those rulings. Their main market is me and my friends that like to ride high end bikes on Sundays.

And a lot of people on this thread live in flatlands. The mountain behind my house is a 4K foot climb in just over 6 miles and the return 4K descent in four miles of twisty road with deathly cliffs. Like I said, I will use those discs to their potential.


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## BikeLayne (Apr 4, 2014)

.....


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## burgrat (Nov 18, 2005)

They're a solution to a nonexistent problem, imo. They would maybe help in a muddy race like Paris-Roubaix or Flanders, but I don't see them being a great improvement otherwise. In a mountainous ride, for example, wouldn't there be a risk of the hydraulic fluid overheating if you had to ride the brakes a lot? I know that can happen with traditional brakes, but if it happens with discs you can get complete brake failure. No bueno!


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## MR_GRUMPY (Aug 21, 2002)

I can see them being popular with tourists, but (and that's a big BUT), they will never be allowed in road racing, unless everyone is forced to use them. (because of the difference in braking capability) Racer will hate then, because of the slow wheel changed (and the problem of getting disc wheels to be "exactly" matched.
On the other hand, they will be big with the "Fred" crowd, when they want to look like a racer, on a bike that can't be raced.

What's next, disc brakes on a TT bike??
.
PS If your carbon wheels don't brake well, downhill, in the rain, try using wheels with Aluminum rims.


.


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## junior1210 (May 2, 2013)

Discs will gain acceptance just like 11 speed did. I can't say I've ever heard/read how anybody was suffering in their performance because they needed just one more cog in their 11-30 stack (let's say the 16T). Now that you have 11 cogs that problem is gone, well except that the 16T _still_ isn't in the stack for more than half of the cassettes now available. But Shimano sells (or will shortly) 3 road groups of 11 speed, plus Campy and SRAM and the 16T be damned (it's not, the analogy only goes so far).

Discs will be the same thing. They do have some benefits, but enough to change the whole industry? No, but it's a good market selling point, so a few years from now at least half of new bikes will be designed for discs (IMO), and rim calipers will be 'old school' gear for old riders (performance reality not withstanding).


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## BlazingPedals (Apr 4, 2013)

I think it's inevitable that disc brakes will eventually take over the world of cycling. Right now, Tektro is the only MFG that makes a dual-piston mechanical brake, and that'll have to change. Also, weights will have to come down. Yeah, racers might want to keep rim brakes; but the average club rider will clamor for discs when they discover they mean no more rim wear, longer pad life, great stopping power in wet weather, and great modulation.


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## stanseven (Nov 9, 2011)

TJay74 said:


> Why would you want rim brakes??? Less stopping power than disc, horrible performance when wet, weigh more than disc brakes (not only in the brakes but also in extra material in the rim


Rim brakes weigh more? Not in the weights I see. 

Disc brakes are much more temperamental and are finicky to adjust and maintain. Just ask anyone who has them on mountain or cross bikes.


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## 88 rex (Mar 18, 2008)

This thread is useless without pics. I've been racing road races on discs for a few years. Not a big deal. Not sure why everyone cares what everyone else is riding. Consistant and reliable braking is never a bad thing and if you don't have a problem with your rim brakes then keep on rocking them. There will always be rim brakes. There will always be disc brakes. 

If disc brakes had always been the "norm" and someone introduced rim brakes the same folks getting upset about being "forced" to change would still complain. 

It's a bike. You pedal, you smile, you brake and they work, you smile. Its simple. 

17.5 lbs of Fredness. 

Project Flecha - Carbon ISP, Stainless Top Tube, Custom Topper by Wilco Cycleworks, on Flickr


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## pone (Sep 19, 2012)

stanseven said:


> Disc brakes are much more temperamental and are finicky to adjust and maintain. Just ask anyone who has them on mountain or cross bikes.


actually they're really easy. one knob for cable slack/lever pull and another to adjust clearance of pads to rotors. i haven't touched mine in well over a thousand miles.


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## mitchy_ (Aug 20, 2013)

they have/will catch on. doesn't mean everyone has to ride them.

perhaps it's my love of cars, but i've always been an advocate of never being able to have "too much brake".

and yep they are heavier, for now. my 6.92kg disc roadie does ok though.


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## Alex_Simmons/RST (Jan 12, 2008)

Disk brakes are so effective they'll slow you down all the time. #anaeromare


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## Waspinator (Jul 5, 2013)

velodog said:


> They won't catch on in my house. But that ain't gonna stop the manufacturers from forcing them onto the bike buying public.
> 
> I guess that they are a good thing if a person is so ham fisted and lacking in finesse that they cannot modulate a set of rim brakes. They are kinda like ABS brakes on automobiles, where all a person has to know how to do is mash their foot into the floor boards, no finesse needed.
> 
> No need to develop a skill set when someone else can design it into the appliance for you.


No offense, dude, but you really don't understand the purpose of anti-lock brakes, do you. They weren't developed to help people 'modulate' their braking. They were developed to prevent the wheels from locking and the car from sliding out of control in an emergency situation when the driver invariably panics and slams the brakes down. And when I say invariably, I mean invariably. "Emergency" may have slightly different meanings depending on the quality of the driver, but ALL drivers would, if scared enough, slam on the brakes and lock the wheels in the face of impending danger. Yes, the designer of these ABS brakes (who are a lot smarter than you and me) and the governments that mandate them know full well that you and I are as 'ham-fisted' as anyone else in a true emergency.

Not only that, disc brakes aren't made for better modulation. In fact, modulation on disc brakes is markedly worse, and understandably so. They offer better performance in wet conditions and that's pretty much it. As for increased "stopping power"...... pure rubbish - whatever mechanical advantage that is gained by closer proximity between stopping surfaces on a disc brake is almost certainly negated by the mechanical advantage rim brakes have by clutching at a wider radius.


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## planetrobbi (Dec 21, 2013)

I own a 105 shimano braked alloy rim road bike and my 7.6kg disc roadie which is hand built by me  I'm not sure why there is any argument, My SRAM avid road disc bike is set up with full cable housing from lever to caliper through the frame. The braking progression, power and modulation on the disc bike is like night and day compared to my older rim brake bike. Im not just saying it , its a fact. Once you have lived with a disc brake road bike down a descent in the wet or on wet training rides with no change to braking performance you won't want to go back. I am looking to upgrade to the TRP RD/HYD caliper soon, thats gonna be awesome 

View attachment 295575


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## velodog (Sep 26, 2007)

Waspinator said:


> No offense, dude, but you really don't understand the purpose of anti-lock brakes, do you. They weren't developed to help people 'modulate' their braking. They were developed to prevent the wheels from locking and the car from sliding out of control in an emergency situation when the driver invariably panics and slams the brakes down. And when I say invariably, I mean invariably. "Emergency" may have slightly different meanings depending on the quality of the driver, but ALL drivers would, if scared enough, slam on the brakes and lock the wheels in the face of impending danger. Yes, the designer of these ABS brakes (who are a lot smarter than you and me) and the governments that mandate them know full well that you and I are as 'ham-fisted' as anyone else in a true emergency.
> 
> Not only that, disc brakes aren't made for better modulation. In fact, modulation on disc brakes is markedly worse, and understandably so. They offer better performance in wet conditions and that's pretty much it. As for increased "stopping power"...... pure rubbish - whatever mechanical advantage that is gained by closer proximity between stopping surfaces on a disc brake is almost certainly negated by the mechanical advantage rim brakes have by clutching at a wider radius.


None taken.

I understand the purpose of ABS brakes, but I also learned about pumping my brakes growing up without them. That is my comparison, pumping the brakes was a skill developed that isn't developed any more.
As drivers we are further removed from driving our autos than we once were, more in the order of pointing our cars instead of driving them. I guess that it makes it easier to drive distracted so many are happier.

And as far as the modulation and stopping power, they seem to be the stronger arguments for their perceived need.

PS..
You mean the mechanical advantage of a 622mm disc?


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## Waspinator (Jul 5, 2013)

velodog said:


> None taken.
> 
> I understand the purpose of ABS brakes, but I also learned about pumping my brakes growing up without them. That is my comparison, pumping the brakes was a skill developed that isn't developed any more.
> As drivers we are further removed from driving our autos than we once were, more in the order of pointing our cars instead of driving them. I guess that it makes it easier to drive distracted so many are happier.
> ...


You still don't understand.  In an emergency, you will not have the wherewithal to pump your brakes. Don't feel bad: Mario Andretti probably wouldn't either. Both of you, when frightened enough, will slam on the brakes. Guaranteed. Enter ABS brakes, for those very situations.

Not only that, have you ever actually experienced what antilock brakes really do? They pump the brakes very rapidly - far more rapidly than you could ever tap the weight of your own foot up and down (let alone depress and release a brake pedal).


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## pone (Sep 19, 2012)

Waspinator said:


> You still don't understand. In an emergency, you will not have the wherewithal to pump your brakes. Don't feel bad: Mario Andretti probably wouldn't either. Both of you, when frightened enough, will slam on the brakes. Guaranteed. Enter ABS brakes, for those very situations.


that's not true, it just takes practice. spend some time on a track practicing braking at the edge of traction and _that_ becomes an automatic response. synapses and muscle memory can be your friends, too.


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## velodog (Sep 26, 2007)

pone said:


> that's not true, it just takes practice. spend some time on a track practicing braking at the edge of traction and _that_ becomes an automatic response. synapses and muscle memory can be your friends, too.


Thank you.

I've found myself pumping the brakes just as the ABS kicks in. Things could get dicey in those conditions if I was a more aggressive driver.


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## ijuf (May 14, 2012)

You will only need disc brakes on road bikes if you don't know the proper braking techniques. On most roads (99%), you always have time to plan your braking. Anyone who thinks they have had to or might need to clamp down on their brakes with so much power as to make it come to a full stop within seconds, does not know how to use brakes on bikes. 

I mean, come on... use the line of sight as your guide to controlled & planned braking. People who say disc brakes are better for wet conditions, assume that they can ride as well in wet conditions as in dry conditions. The loss of friction applies to all pairs of surfaces in mutual relative motion... to wit... the road & the tire. Don't use slick tires if you intend to ride in the rain. That'll solve your braking issues.

To be honest, I say those clunky ugly disc brakes don't belong on the sleek, minimalist clean lines of a road bike.


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## 88 rex (Mar 18, 2008)

ijuf said:


> You will only need disc brakes on road bikes if you don't know the proper braking techniques. On most roads (99%), you always have time to plan your braking. Anyone who thinks they have had to or might need to clamp down on their brakes with so much power as to make it come to a full stop within seconds, does not know how to use brakes on bikes.
> 
> I mean, come on... use the line of sight as your guide to controlled & planned braking. People who say disc brakes are better for wet conditions, assume that they can ride as well in wet conditions as in dry conditions. The loss of friction applies to all pairs of surfaces in mutual relative motion... to wit... the road & the tire. Don't use slick tires if you intend to ride in the rain. That'll solve your braking issues.
> 
> To be honest, I say those clunky ugly disc brakes don't belong on the sleek, minimalist clean lines of a road bike.


When one rides in an uncontrolled environment, there will always be unplanned braking.


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## Special Eyes (Feb 2, 2011)

ijuf said:


> To be honest, I say those clunky ugly disc brakes don't belong on the sleek, minimalist clean lines of a road bike.


It is the absence of caliper brakes that make those sleek, minimalist clean lines of a road bike even nicer.


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## Srode (Aug 19, 2012)

velodog said:


> None taken.
> 
> I understand the purpose of ABS brakes, but I also learned about pumping my brakes growing up without them. That is my comparison, pumping the brakes was a skill developed that isn't developed any more


pumping brakes is a good skill to have, but even with great skills it's darned near impossible to out brake a car with ABS vs no ABS, lots of studies to show that. ABS stops faster.


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## ijuf (May 14, 2012)

88 rex said:


> When one rides in an uncontrolled environment, there will always be unplanned braking.


uncontrolled environment aka mountain biking, not road biking.


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## ijuf (May 14, 2012)

Special Eyes said:


> It is the absence of caliper brakes that make those sleek, minimalist clean lines of a road bike even nicer.


Are you kidding? Have you seen the skeleton brakes from Campy? They disappear behind the fork.


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## Camilo (Jun 23, 2007)

pone said:


> that's not true, it just takes practice. spend some time on a track practicing braking at the edge of traction and _that_ becomes an automatic response. synapses and muscle memory can be your friends, too.


OK, I'm speaking of someone who grew up in the north learning to drive on icy roads and has spent 44 years driving on icy roads, 6+ months per year. Your comment is just so unrealistic. Go to a track and practice braking on the edge of traction as a practical alternative to ABS? Seriously?

Plus, ABS just works better - and again, I probably have more icy road experience than 99% of drivers and seriously learned to brake on ice from the very earliest stages in my driving.

As for the original point of this thread....

I have only ridden one "road" disc brake bike (a cross bike but set up for road riding). I didn't have any problem with the brakes other than they were noisy just from the dust on the road. Not mud, not mal-adjustment (I don't think), just a quiet noise that would build up and then disappear when I applied the brakes. Kind of annoying.

If conventional rim brakes will stop you within the ability of the small contact patch of a typical road tire on pavement, what advantage to disks give you for the typical roadie?


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## pone (Sep 19, 2012)

we were talking about modulating brakes, and it was claimed that it isn't possible for a person to modulate properly during emergency stops. it doesn't matter where you grow up, that isn't true. emergency braking is a good thing to practice, though, especially if you're concerned about a lack of ABS on your bicycle.


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## Special Eyes (Feb 2, 2011)

ijuf said:


> Are you kidding? Have you seen the skeleton brakes from Campy? They disappear behind the fork.


No dude, I'm not kidding. What kind of reply is that? NO BRAKES are clearly sleeker than any, except of course for the ones YOU happen to like.


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## 88 rex (Mar 18, 2008)

ijuf said:


> uncontrolled environment aka mountain biking, not road biking.



Real world riding involves inattentive drivers.


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## BikeLayne (Apr 4, 2014)

......


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## 74extiger (Jan 29, 2011)

In physics they define Rolling Friction and Sliding Friction. Your tires exert more stopping power while Rolling. A disk mechanism could lock up your wheel, resulting in a slide. 
The is slower to stop, and is likely to skid out of control. 

Lots of canyons here in the western part of Los Angeles. I don't have any problem controlling 40+mph descents on my road bike. Caliper brakes. I've never even had the rim heat up in summer conditions. I run a cloth dipped in paint thinner over the rim to keep the braking surface clean.


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## Kaboom (Jul 18, 2003)

If the bike is upright as opposed to leaning in a turn and you're riding on asphalt (not dirt, sand, slippery stone sidewalks etc), there is no way in hell you're going to lock up your front wheel with either rim or disk brakes. Even the crappiest double-pivot rim brakes have way more than enough power to send you over the bars way before a the front wheel locks.

As it has been said a million times, its no about stopping power, its about modulation.

And as it has been said half a million times, it is really, really hard to justify the weight and price penalties for the gains in modulation.

Me? I'll be getting them at some point in the near future because I think they're cool and I really enjoy riding in traffic like a maniac where the greater modulation capacity might be useful.

But really, they're just another way to blow those 500$ no one buying them really needs for anything actually relevant...


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## tlg (May 11, 2011)

88 rex said:


> Consistant and reliable braking is never a bad thing and if you don't have a problem with your rim brakes then keep on rocking them. *There will always be rim brakes*. There will always be disc brakes.


I wouldn't be so sure about that. Shimano only makes MTB rim brakes for Alivio and Acera (9sp). Every other group is only available in disc. Sram doesn't have a MTB rim brake at all. 
You'd be hard pressed to find a new MTB with rim brakes. Probably couldn't even buy a bike and swap wheels and brakes with aftermarket rim brakes because frames and forks won't have mounts for them.


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## MMsRepBike (Apr 1, 2014)

tlg said:


> I wouldn't be so sure about that. Shimano only makes MTB rim brakes for Alivio and Acera (9sp). Every other group is only available in disc. Sram doesn't have a MTB rim brake at all.
> You'd be hard pressed to find a new MTB with rim brakes. Probably couldn't even buy a bike and swap wheels and brakes with aftermarket rim brakes because frames and forks won't have mounts for them.


There's no mud clearance or mud issues at all really in road biking.
No reason why rim brakes won't stick around.

What I can see is no more carbon wheels with braking surfaces on them, that's entirely practical. But rim brakes and aluminum wheels are not going anywhere on road bikes.


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## 88 rex (Mar 18, 2008)

tlg said:


> I wouldn't be so sure about that. Shimano only makes MTB rim brakes for Alivio and Acera (9sp). Every other group is only available in disc. Sram doesn't have a MTB rim brake at all.
> You'd be hard pressed to find a new MTB with rim brakes. Probably couldn't even buy a bike and swap wheels and brakes with aftermarket rim brakes because frames and forks won't have mounts for them.


True. This is very true from a mass production standpoint, and I should add that I was thinking more along the lines of the prodcuts will always be available for those who REALLY want them. Custom retro builds still happen and as long as Paul Components keeps pumping out beautiful shiny bits, people will keep using canti's and every other rim brake under the sun. Plus you have your touring and 3rd world country bikes where I could see Canti's or calipers being somewhat of an advantage in some folks eyes. 

And let's not forget the dedicated weight weenie who drills holes into all kinds of things to drop every last gram. Caliper brakes will be lighter, even if only marginal in some instaces, and for those favoring gram loss above all else, this will be their stopping method of choice. 

For me, I'm all disc brakes now. All the advantages outweigh the disadvantages and it really is up to the end user to do their own analysis of what's best for them. I think people tend to take this topic WAY to personal. Looking at my current queue of things to build I see a mix of disc and caliper and each really does suit their future owners needs well.


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## SauronHimself (Nov 21, 2012)

74extiger said:


> In physics they define Rolling Friction and Sliding Friction. Your tires exert more stopping power while Rolling. A disk mechanism could lock up your wheel, resulting in a slide.
> The is slower to stop, and is likely to skid out of control.


What you said wasn't false, but the terms need a little clarification. The two types of contact friction are static and kinetic. Static friction is experienced when an object is not moving relative to the surface it's touching. Kinetic friction is experienced when that object is sliding along said surface. The coefficient of static friction is larger than the coefficient of kinetic friction. Since the contact patch of a tire is technically immobile with respect to the road, a properly functioning tire should always experience static friction. Skidding a tire converts the friction to kinetic, which is a weaker force, and thus you can't stop as quickly. This is the primary motivation behind ABS; it keeps car tires rolling instead of sliding so the flat spot and, in turn, static friction are always present.


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## fn1889m (Feb 27, 2011)

I have two road bikes one with disc, and one without. Still a "new rider" after 2-3 years. But the only problem I see is that the disk brakes are a little more complicated to adjust. It took me a bit to figure out the adjustment mechanism and the tolerances. It is a little less visually apparent on disk brakes. But once set up, they work better. And they stay adjusted once set up. Both work well enough at my speeds. But if I were a faster rider, disc brakes might be an advantage. Otherwise, they are brakes. I think the objection is to change.


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## nhluhr (Sep 9, 2010)

Marc said:


> You really think so? When there exist mountain descents that can cause a bike rim to overheat enough from rim-braking to cause tire blowouts or a carbon wheel to come apart from friction on a breaking surface 622mm in diameter...you question whether or not a disc-brake that is a mere 1/5th the size in diameter (and therefore circumference) will get hot enough to screw with the temperature of your hub bearings?


Shimano completely eliminates this issue by firstly providing significant heat-sinking to dissipate heat to the air and also by isolating the hot part from the hub via isolation bushings where the friction plate attaches to the hub spider piece. I'd agree that brands not taking approaches like this are pushing the envelope with heat but even with that, hub bearings have not been an issue for any of my teammates using Avid disc brakes on their training bikes.


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## Camilo (Jun 23, 2007)

pone said:


> we were talking about modulating brakes, and it was claimed that it isn't possible for a person to modulate properly during emergency stops. it doesn't matter where you grow up, that isn't true. emergency braking is a good thing to practice, though, especially if you're concerned about a lack of ABS on your bicycle.


I guess we might disagree on what's possible. I'll give you that an extremely well-practiced driver who always drives perfectly can modulate his/her brakes. I'm saying that's far closer to theoretical truth than practical or real world truth. ABS - used by the entire population of drivers - is far, far, far better than "modulation".

I'm sorry that you don't think that over 40 years driving icy roads, and actually learning and practicing "modulation" (aka "pumping") and using that technique until about 15 or so years ago doesn't qualify me to have a fairly expert opinion on the matter. Since you have pretty much said my experience doesn't matter, what's your basis for your expert opinions?


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## pone (Sep 19, 2012)

damn, that shimano set up looks very nice.



Camilo said:


> I guess we might disagree on what's possible. I'll give you that an extremely well-practiced driver who always drives perfectly can modulate his/her brakes. I'm saying that's far closer to theoretical truth than practical or real world truth. ABS - used by the entire population of drivers - is far, far, far better than "modulation".
> 
> I'm sorry that you don't think that over 40 years driving icy roads, and actually learning and practicing "modulation" (aka "pumping") and using that technique until about 15 or so years ago doesn't qualify me to have a fairly expert opinion on the matter. Since you have pretty much said my experience doesn't matter, what's your basis for your expert opinions?


you seem to be responding to comments i haven't made. i'm sure you're the one best qualified to say what your own braking abilities are.


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## mambo (Jul 29, 2012)

The implementation of disc brakes on road bikes is completely industry driven.

The fact is that normal caliper brakes have more than enough stopping power and modulation. The newer carbon rims have no problem stopping and it's years since I saw one overheat (I live in an area with lots of mountains and +40c temperatures in summer) and then it was a rider who is scared when descending and de-laminated a cheap Chinese rim in summer but had spent almost a whole 12k downhill average 8% gradient on the brakes.

Discs are heavier, disc frames are heavier and if you puncture they are a pain to set up so they don't rub.

Now, thru axles would be an advance and I hope they get introduced quickly as they would make everything stiffer, and as any girl will confirm, stiff is good!


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## 88 rex (Mar 18, 2008)

mambo said:


> Discs are heavier, disc frames are heavier and if you puncture they are a pain to set up so they don't rub.
> 
> Now, thru axles would be an advance and I hope they get introduced quickly as they would make everything stiffer, and as any girl will confirm, stiff is good!


1) Disc frames are not heavier. 

2) Thru axle is not an advancement, and if anything, is far more industry driven than disc brakes. Not really sure what folks think is going to stiffen up. In the mountain bike world, thru axle rear on hardtails and rigid forks are not noticably "stiffer". With suspension, yes, rigid, no. It's interesting to me that some shun better braking, something customers actually ask for, but are intrigued with thru axles, which no one is asking for. On top of that, you'll never get thru axles without disc brakes, so with thru axles you can't have it one way or the other.


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## mambo (Jul 29, 2012)

88 rex said:


> 1) Disc frames are not heavier.
> 
> 2) Thru axle is not an advancement, and if anything, is far more industry driven than disc brakes. Not really sure what folks think is going to stiffen up. In the mountain bike world, thru axle rear on hardtails and rigid forks are not noticably "stiffer". With suspension, yes, rigid, no. It's interesting to me that some shun better braking, something customers actually ask for, but are intrigued with thru axles, which no one is asking for. On top of that, you'll never get thru axles without disc brakes, so with thru axles you can't have it one way or the other.


Disc frames are heavier. I am including the frame and forks in my calculations.

When one of the best carbon frame builders in the industry tells me he can build an inherently stiffer carbon frame adapting the use of thru axles - I believe him.

Better braking is good, but without the weight penalties and adjustability problems when you puncture. In almost 40 years of riding I have never had a problem for lack of braking or modulation, all of my near misses were my own fault even with the old Weinmann brakes!

Could thru-axles be implemented without discs? - who knows


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## aclinjury (Sep 12, 2011)

I notice that so far, disc has been popular with mostly the older crowds, the folks who enjoy doing long and slow centuries or double centuries through rain, folks who ride with ride with 5 lights minimum, neon windbreaker flapping like parachutes, 3-4 water bottles, and a toolshed plus a spare tire anchored to their seatpost.

For the fast riding crit guys, for the coffee crew guys, for the (sometimes obnoxious) Saturday-hammerheads guys , I haven't seen them embrace disc brakes, not even close yet.

Disc will be pushed on to buyers, but it remains to be seen to what extent. My bet is that the latter group that I mentioned above will not embrace disc at all, while the casual folks, the older folks, or folks living in wet areas, will adopt.


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## LVbob (Mar 24, 2014)

Seems this topic is quite religious.


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## mambo (Jul 29, 2012)

aclinjury said:


> I notice that so far, disc has been popular with mostly the older crowds, the folks who enjoy doing long and slow centuries or double centuries through rain, folks who ride with ride with 5 lights minimum, neon windbreaker flapping like parachutes, 3-4 water bottles, and a toolshed plus a spare tire anchored to their seatpost.


Ha ha. You forgot to mention the wife on the back of the tandem as well!!!

It's what the industry is pushing for. We had a discussion amongst the 30 or so riders in our group the other day and not a single one was interested in disc brakes. The magazines and internet will brainwash some of them though.


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## 88 rex (Mar 18, 2008)

mambo said:


> Disc frames are heavier. I am including the frame and forks in my calculations.
> 
> When one of the best carbon frame builders in the industry tells me he can build an inherently stiffer carbon frame adapting the use of thru axles - I believe him.
> 
> ...


Fork will be 50-100g heavier. Frames will be identical.

If he said that, he's wrong.

No. You won't get thru axles without discs.


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## velodog (Sep 26, 2007)

Some will resist.


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## nhluhr (Sep 9, 2010)

88 rex said:


> 1) Disc frames are not heavier.





mambo said:


> Disc frames are heavier. I am including the frame and forks in my calculations.


Good thing we have the experts on the case.

I'm casting my vote for disc frames are heavier based solely on the necessity for additional strength in places a caliper bike never needed it.


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## Waspinator (Jul 5, 2013)

Kaboom said:


> If the bike is upright as opposed to leaning in a turn and you're riding on asphalt (not dirt, sand, slippery stone sidewalks etc), there is no way in hell you're going to lock up your front wheel with either rim or disk brakes. Even the crappiest double-pivot rim brakes have way more than enough power to send you over the bars way before a the front wheel locks.
> 
> As it has been said a million times, its no about stopping power, its about modulation.
> 
> ...


Dude, disc brakes don't allow for better modulation. They are worse in this respect. This is common knowledge. 

And it makes sense why. The pad movement for braking occurs over a much smaller distance. A rim brake moves over a millimeter in order to brake. A disc brake moves maybe a half millimeter? It's much harder to 'modulate' the movement of something when the increments you have to move it in order to modulate become so small.


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## DrSmile (Jul 22, 2006)

I have to agree that the people I see riding discs on the road for now appear to be older bearded types that seem umm... more nerdy than sporty (my guess is they are from the wealthier areas around here). The Epo infused maniacs fly by me sans discs, and that's probably because of the ~300 gram penalty. It's either that or the disc brakes may make their carbon frames explode.


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## MoPho (Jan 17, 2011)

aclinjury said:


> I notice that so far, disc has been popular with mostly the older crowds, the folks who enjoy doing long and slow centuries or double centuries through rain, folks who ride with ride with 5 lights minimum, neon windbreaker flapping like parachutes, 3-4 water bottles, and a toolshed plus a spare tire anchored to their seatpost.
> 
> For the fast riding crit guys, for the coffee crew guys, for the (sometimes obnoxious) Saturday-hammerheads guys , I haven't seen them embrace disc brakes, not even close yet.
> 
> Disc will be pushed on to buyers, but it remains to be seen to what extent. My bet is that the latter group that I mentioned above will not embrace disc at all, while the casual folks, the older folks, or folks living in wet areas, will adopt.


Of course the crit guys, hammerheads, etc, haven't embraced discs, they're illegal for racing and haven't really been available on race bikes, can't embrace something that you can't buy yet. 
Come back in a year or two, the Spec Tarmac is now offering disc, I hear the Giant TCR will have a disc option too next year and I am sure there will be more. 
Had the TCR been available with hydro disc 5 months ago when I ordered mine I would have bought it with disc.










Waspinator said:


> Dude, disc brakes don't allow for better modulation. They are worse in this respect. This is common knowledge.
> 
> And it makes sense why. The pad movement for braking occurs over a much smaller distance. A rim brake moves over a millimeter in order to brake. A disc brake moves maybe a half millimeter? It's much harder to 'modulate' the movement of something when the increments you have to move it in order to modulate become so small.



Road Bike Disc Brakes Review & Preview | Bicycling Magazine




Bicycling Magazine article said:


> It's About Control, Not Power
> 
> Many cyclists assume the biggest reason to switch to disc brakes is to gain stopping power. While hydraulic disc brakes on a road bike would almost certainly be more powerful than existing rim brakes, the bigger benefit is actually that cyclists would get control over the available power.
> 
> ...


The hydraulic fluid also adds to the modulation and feel offered by disc brakes.


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## mambo (Jul 29, 2012)

88 rex said:


> Fork will be 50-100g heavier. Frames will be identical.
> 
> If he said that, he's wrong.
> 
> No. You won't get thru axles without discs.


As a frame won't work without forks, the set up is heavier. Correct?

I see you are a frame builder but build steel only. With all due respect I have to go with the guys who have been building frames for over 50 years in steel, Ti and carbon. I was listening to a conversation between three people who had a combined 100 years of frame building experience! 

No thru-axles without discs? Only until a custom frame builder decides to offer them as an option.


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## aclinjury (Sep 12, 2011)

MoPho said:


> Of course the crit guys, hammerheads, etc, haven't embraced discs, they're illegal for racing and haven't really been available on race bikes, can't embrace something that you can't buy yet.
> Come back in a year or two, the Spec Tarmac is now offering disc, I hear the Giant TCR will have a disc option too next year and I am sure there will be more.
> Had the TCR been available with hydro disc 5 months ago when I ordered mine I would have bought it with disc.
> 
> ...


Let me rephrase. The crit guys don't show desire to embrace disc.


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## aclinjury (Sep 12, 2011)

There is a couple guys in our club who got disc. One got a Colnago C59 disc, the other got a Volagi. The reason both of them got disc because they are timid descenders, and one of them even blow out the tire on his CARBON rim in a descent once becaue he was dragging his brakes. Notice the common theme here. Noob riders who can't descend, and noob rider who can't descend AND riding carbon rims. I reckon these noobs are the product of advertising and marketing.

Anyway, they got their disc bikes, thinking that they would be able to descend faster now. Wrong. They are still slow, in fact slower than about almost all the girls on any given ride. I can definitely say that disc brakes have more marketing in them than actual solution.


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## MoPho (Jan 17, 2011)

aclinjury said:


> Let me rephrase. The crit guys don't show desire to embrace disc.


Let me rephrase. Who gives a crap what crit guys desire?! You don't really need brakes for crit riding, and again, they are not allowed.yet.

And people who actually race are a very small percentage of riders out there, so not exactly a good sampling of the real world. 





aclinjury said:


> There is a couple guys in our club who got disc. One got a Colnago C59 disc, the other got a Volagi. The reason both of them got disc because they are timid descenders, and one of them even blow out the tire on his CARBON rim in a descent once becaue he was dragging his brakes. Notice the common theme here. Noob riders who can't descend, and noob rider who can't descend AND riding carbon rims. I reckon these noobs are the product of advertising and marketing.
> 
> Anyway, they got their disc bikes, thinking that they would be able to descend faster now. Wrong. They are still slow, in fact slower than about almost all the girls on any given ride. I can definitely say that disc brakes have more marketing in them than actual solution.



So basically you've come to this conclusion not from experience, but from being judgmental of people who aren't up to your standards of ability.... got it 


I am a pretty aggressive descender, as a matter of fact my times down my favorite technical descent are approaching those of the pros who did it on a closed road and I would love to have disc brakes. I save a good 10-20s on alloy wheels over my carbon because I can brake later for the corners, but I like my carbon wheels better the rest of the time. I want to have my cake and eat it too. I could probably save even more time with disc brakes. 
But more important than saving time, I want better brakes for the unexpected moments, like on Monday when I came into a blind hairpin corner at 30+mph to find a truck full of outhouses (for the Tour of California stage) stuck on the wrong side of the road. I got lucky in that I caught a glimpse of it through the trees one corner before or I wouldn't have been able to stop and it would have been a crappy situation. 
Moments later while I was going over 40mph some old lady drifted into my lane and nearly hit me head on, could have used some better brakes then too.
On Wednesday I had a wild turkey run out in front me and Saturday it was a deer. 
Sometimes I even get stuck behind cars and have to ride the brakes all the way down the mountain like a "noob". :cornut:


You can snub your nose at the noobs and spew all the BS you want about how amazing a rider you think you are but you never know when to expect the unexpected and you don't need good brakes until you do. 


One of the guys on my team crashed when his front tire blew out after we were coming down a 40+mph hill only to have the light at the bottom turn red and we had to jam on the brakes HARD. Not a noob, he is a very experienced rider, just a tough braking situation. A bit of a silly thing to transfer the heat into your tires, you carefully set tire pressures only to have the pressure go up right as you enter a corner. Brilliant! 




Every article I've read where the journos rode disc brake road bikes they were raving about them and it matches my personal experiences with my mtb and commuter bikes which have hydor disc brakes, they are amazing. 
Disc brakes are certainly more useful than electronic shifting and that seems to be taking off too.


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## ijuf (May 14, 2012)

88 rex said:


> Real world riding involves inattentive drivers.


That's true, but as long as you follow traffic rules, and ride with the other traffic, your chances of needing to brake hard are much much lower than your chances of getting hit from behind by a car. 

I mean... having disc-brake-stopping-power is not an excuse to not be cautious. So then, caution clearly makes redundant any advantage that extra stopping power may provide.


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## ijuf (May 14, 2012)

Special Eyes said:


> No dude, I'm not kidding. What kind of reply is that? NO BRAKES are clearly sleeker than any, except of course for the ones YOU happen to like.


Yes, no brakes are the best. That is why track bikes which have no freehub and no brakes are the most minimalist, sleekest, and most energy efficient bike design out there. If all roads were inside velodromes, then I would always be riding track bikes. 
But clearly in the real world there is a need for a set of brakes. 

And I'm not stuck to any brand... I only like Campy brakes because they are so sleek and still perform great.


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## MMsRepBike (Apr 1, 2014)

I can easily lock up my wheels with rim brakes. Easily, it's really not hard. Modulation is superb, tons of control and limitless braking power. Well once you lock the wheels the braking power is at a limit, so yeah, that. Disc brakes do have a bit more control/modulation though, no matter if the distance to clamp is smaller or not.

Having more braking power is never going to be an argument for disc brakes. Better control, yes. You will be very hard pressed to do a front wheel manual downhill on a road bike with rim brakes, I dare say you can't do it. But with disc brakes it's very much possible and has been done. The level of control with discs is undeniably better. The braking power though is not an issue, like I said you can easily lock a wheel with rim brakes or disc brakes.


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## FastWayne (May 20, 2014)

not true. I ride mt and road bikes. Shimano is the best of the lot. smooth and powerful. not to mention they work in the wet. I would love to have disc on my road bike.


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## FastWayne (May 20, 2014)

Ha the old disc brake argument again? I love it. Roadies hate change; ) I for one would love to have disc on my road bike. I would have to change frames tho. They are better in the wet, and on fast down hills where you have to come to complete stop like a T intersections. Yes I ride those. I have melted my alloy rims and gouged the rims. In a heavy mist or fog they fail until you clean off the rims. not fun if your not ready for it. I also love the look, probably because I have disc on my mt bike and rim brakes look so antiquated. 

They do weigh more, they probably will get lighter as mt bike brakes have.

I have never liked the feel of road bike brakes, I've had Campy Record and Ultegra with Kswiss pads, crappy. That's just me, everyone who hates disc, just don't buy them.


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## 88 rex (Mar 18, 2008)

nhluhr said:


> Good thing we have the experts on the case.
> 
> I'm casting my vote for disc frames are heavier based solely on the necessity for additional strength in places a caliper bike never needed it.


Additional strength isn't needed when mounting on the chainstay. If mounting on the seatstay you need a tiny tube for reinforcement. Minimal gain, or neglibible if you remove the seat stay bridge which is present for caliper brakes and/or fenders.


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## 88 rex (Mar 18, 2008)

mambo said:


> I see you are a frame builder but build steel only. With all due respect I have to go with the guys who have been building frames for over 50 years in steel, Ti and carbon. I was listening to a conversation between three people who had a combined 100 years of frame building experience!
> 
> No thru-axles without discs? Only until a custom frame builder decides to offer them as an option.


1) The material is not the problem. Regardless of materials, a thru axle isn't going to make any noticable or appreciable difference on a road bike. It has gained ground for mountain bikes because of linkages and moving suspension. The TA makes a big difference when all the parts have pivots. It ONLY makes sense for someone who is coming from a MTB background and has a plethora of TA wheels that can accept road tires. That pool of people is very very very tiny.

2) If you really want a TA road bike, it's pretty easy to build. Just use disc hubs sans discs laced to road rims and 135/142 rear spacing. It's already an option. I've built something with similar spacing but with QR instead of TA.


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## Whacked (Feb 14, 2011)

Waspinator said:


> Dude, disc brakes don't allow for better modulation. They are worse in this respect. This is common knowledge.
> 
> And it makes sense why. The pad movement for braking occurs over a much smaller distance. A rim brake moves over a millimeter in order to brake. A disc brake moves maybe a half millimeter? It's much harder to 'modulate' the movement of something when the increments you have to move it in order to modulate become so small.


Curious.
Have you actually RIDDEN a bike with disk brakes?
Modulation has nothing to do with distance between pad and braking surface. Modulation = change. More specifically, small, smooth increments of change. In regards to brake modulation, this means the change from free spinning to complete stop or lock-up. 
Ride a bike with a good quality and well set up disk brakes and you sill sing a different tune.

I think that disk road bikes will eventually become the standard. Technology will improve to the point that weight weenies will approve, and of course, quality always improves. Calipers will be around forever but I think eventually they will only be found on entry level bikes.

Now, if that happens in my lifetime, that is a whole 'nother can of beans.


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## SMK-SLC (May 3, 2012)

*2016 will be the year*

According to Road.cc and UCI they will catch on in 2016:

UCI-approved road bike disc brakes coming in 2016, says WFSGI's bike man | road.cc


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## tom_h (May 6, 2008)

*Target consumer for road discs ...*

... overweight Hawaii tourists on a "coast down Haleakala volcano road" tour?


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## MMsRepBike (Apr 1, 2014)

what the hell? are those like crash suits? ahahaha.


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## tlg (May 11, 2011)

MMsRepBike said:


> what the hell? are those like crash suits? ahahaha.


It's "Volcano Road". Those are lava suits... in case they crash into a volcano.


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## DrSmile (Jul 22, 2006)

I despised nothing more than the bike vans passing me as I rode up Haleakala. It was a nice feeling flying by all the tourists on MTBs on the way back down though!

Haleakala is a 10,000 ft descent... and no, I didn't need discs to go down! :devil:

I will admit however that my hands were killing me descending Kaloko Drive on the Big Island.


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## Tschai (Jun 19, 2003)

Well, I've been riding for 56.3 years. I have also been driving in wet, icy, hot and dusty road conditions for 60 plus years. I am an expert at both braking and not braking. Sometimes life needs to be kept simple. Disc brakes are better. It's that simple. As such, we will some day see them standard on road bikes. Deal with it.

PS: Sheldon Brown and the others now writing on his site are not bike gods. Sheldon was wrong about many things, including the lack of need for a rear mountain bike brake.


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## Camilo (Jun 23, 2007)

pone said:


> damn, that shimano set up looks very nice.
> 
> 
> 
> you seem to be responding to comments i haven't made. i'm sure you're the one best qualified to say what your own braking abilities are.


I guess so - I'm sorry. I'm not keepng proper track of the automobile/ABS argument and the bicycle brake modulation/disk vs. rim brake argument. As a consolation and attempt to make it right, I offer this:

Argument Clinic - YouTube


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## 8toes (Feb 28, 2010)

Marc said:


> Ish. But I'd barely count 1-in-10 or less (*guesstimate*) retail road bikes as even being capable of mounting them, never mind being sold with them, as having caught on.


I hate when I see this non-word.


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## Marc (Jan 23, 2005)

8toes said:


> I hate when I see this non-word.


Non-word? You'd better take it up with Oxford.

guesstimate: definition of guesstimate in Oxford dictionary (American English) (US)


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## peter584 (Aug 17, 2008)

obed said:


> I think it will eventually be forced by the mfg.


Not until they *MAKE* the pro peloton ride them and quit producing rims brakes, but it looks headed that way. I've ridden about 25 years road and mtn and been through all the transitions. I'm sort of a sucker for new tech and get a new bike every 2-3 years. Disc standards on a road bike are going to take a while to become uniform. I'll probably wait 5 years before my next road bike. Wheelsets that aren't interchangeable are too expensive to jump right right in. I personally think they will end up being thru axle. I bought a cross bike with disc and got the ping of the inevitable warped rotor. You can keep adjusting them, but I'm the same with creaks I can't ride for hours with certain noises. It's all I think about and I'm out there to clear my mind and find peace essentially. I sold the cross bike after one season. Will be happily looking for the last quality cantilever frames on discount soon!


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## pone (Sep 19, 2012)

camilo said:


> i guess so - i'm sorry. I'm not keepng proper track of the automobile/abs argument and the bicycle brake modulation/disk vs. Rim brake argument. As a consolation and attempt to make it right, i offer this:
> 
> argument clinic - youtube


:biggrin5:

..


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## BikeLayne (Apr 4, 2014)

.....


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## nealric (Jul 5, 2007)

I feel like most of the anti-disc crowd does not ride mountain bikes. For me, the improved feel is worth it by itself. I've also had a heat-related flat on a long downhill- one of those is enough.

Weight really won't be that much of an issue. Wouldn't be surprised if disc bikes can get into the sub 15 lb range.


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## Special Eyes (Feb 2, 2011)

nealric said:


> I feel like most of the anti-disc crowd does not ride mountain bikes.


That's probably correct. When I ride my mtbike (not that often) I feel like I can stop the world. Those brakes are powerful. Of course, the contact patch is much larger, too.

I just ordered my first road bike with discs. Really looking forward to it.


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## 9W9W (Apr 5, 2012)

I had discs on a Trek FX a while back. The modulation, control and stopping power were out of this world. I don't care much for stopping power, as after a certain point your ass has to be hanging off the back (which I do sometimes on descents which terminate at intersections), but the ability to gently bleed and control speed was unparalleled. I really do think a lot of the guys need to ride discs - hydraulic discs to be specific - before saying it's a useless technology. The buttery smooth application and feedback you get from that hydraulic lever is great. 

I do agree on all the issues of standards, comparability and comparability.


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## Camilo (Jun 23, 2007)

nealric said:


> I feel like most of the anti-disc crowd does not ride mountain bikes. For me, the improved feel is worth it by itself. I've also had a heat-related flat on a long downhill- one of those is enough.
> 
> Weight really won't be that much of an issue. Wouldn't be surprised if disc bikes can get into the sub 15 lb range.


Two things (speaking for myself): first, it's not "anti-disc" which implies you actually oppose the use of them. It's "why disc" which implies that you haven't seen a compelling reason for disc brakes on a typical road bike. I haven't seen an improvement beyond good rim brakes, because good rim brakes provide stopping power well exceeding the small tire patch to stop the bike, and modulation is excellent. Discs can't improve the stopping power of the tire itself.

Second, I do ride mountain bikes and therefore know that road bikes and mountain bikes are considerably different applications. As are other valid uses for discs like possibly heavy all weather touring, cross, and all weather commuting. Mountain bikes ride in much dirtier and wetter conditions in general. Plus, the tires on a mountain bike (and the other applications I mentioned) are far less limited in their ability to provide stopping power, therefore more stopping power at the brake itself is warranted. Plus if the brakes get a little noisy you probably don't even notice it, it's worth it because of the better braking, and braking occurs more often.

I'll be more than happy to ride a disk road bike if:

it's dead silent at all times
is on a wheel and frame that has no weight penalty
is as easy and quick to remove and replace (which I do every single day) as a rim brake wheel
is as easy to switch between bikes
actually provides better *functionality* than good rim brakes.

Every one of those features is important to me, and since I don't think discs provide better braking on a typical road bike (certainly not on mine, the way I use them), there's absolutely no point putting up with inferior features. Like I think I mentioned earlier, the only disk bike I've ridden on the road had none of those features and therefore I wasn't sold on the concept.

Do you think all of the above will be true in a few years? If so, bring it on.


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## BikeLayne (Apr 4, 2014)

.....


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## mambo (Jul 29, 2012)

Camilo said:


> Two things (speaking for myself): first, it's not "anti-disc" which implies you actually oppose the use of them. It's "why disc" which implies that you haven't seen a compelling reason for disc brakes on a typical road bike. I haven't seen an improvement beyond good rim brakes, because good rim brakes provide stopping power well exceeding the small tire patch to stop the bike, and modulation is excellent. Discs can't improve the stopping power of the tire itself.
> 
> Second, I do ride mountain bikes and therefore know that road bikes and mountain bikes are considerably different applications. As are other valid uses for discs like possibly heavy all weather touring, cross, and all weather commuting. Mountain bikes ride in much dirtier and wetter conditions in general. Plus, the tires on a mountain bike (and the other applications I mentioned) are far less limited in their ability to provide stopping power, therefore more stopping power at the brake itself is warranted. Plus if the brakes get a little noisy you probably don't even notice it, it's worth it because of the better braking, and braking occurs more often.
> 
> ...


I couldn't have said it better myself!

I'd add one caveat - when they are just as light!


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## Camilo (Jun 23, 2007)

mambo said:


> I couldn't have said it better myself!
> 
> I'd add one caveat - when they are just as light!


Thanks. The weight was what I was getting at in the second on the list of features ("no weight penalty"). I can accept measuring the whole package, not just the brakes themselves. But am fairly skeptical about the theory that rims can be lighter making up for the weight of the rotor, even if the tiny marginal difference in weight distribution from the center (rotor) to outside (rim) is significant (I don't think those differences are significant). 

I'll be interested to see the day when a disc wheel can be as light as a rim brake wheel of a similar quality build ..... and that a disc frame and fork can be as light as a similar quality rim brake frame and fork... and that disc calipers can be as light as road calipers (maybe already? I have no idea). 

I'm no engineer, but kinda understand levers... and wonder how a fork with braking forces at the furthest extent of the lever arm (dropouts) can be built as light as one with the forces near the fulcrum (head tube).

Anyway, I do believe in technical progress in bicycling. Although I have a steel bike with downtube shifters which I absolutely love to ride, I also love my nearly all CF bike with contemporary components. And, I will try electronic shifting as soon as I have the chance. And... I did try a road disc bike the first opportunity I had and just wasn't sold... yet. I'll be happy and no curmudgeon if better brakes are available at no cost of the other factors that are important to me.


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## mambo (Jul 29, 2012)

Camilo said:


> Thanks. The weight was what I was getting at in the second on the list of features ("no weight penalty").


Sorry, I missed that one!


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## Special Eyes (Feb 2, 2011)

Camilo, That's a good list. I use those factors to help me decide. However, I personally do not need ALL those criteria met. I certainly do like light bikes, but as I age, those small differences in weight are no longer important. Carrying two full H2O bottles negates one to two thousand dollars worth of weight weenie investments. In the long run (which is typically over 60 miles on weekend rides and less than that during the week) my comfort and safety are main concerns. However I have not lost my drive for performance, just adjusted it slightly. And, that 3500' mountain behind my house is beckoning me to climb it and then descend it safely.


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## DrSmile (Jul 22, 2006)

If I may draw a dental analogy.... 30 years ago dental composites were touted as the perfect replacement for the "evil, toxic, cancer and dementia causing" amalgam. People spent lots of money switching out their silver fillings for white composite ones despite zero REAL scientific evidence.

Thirty years later with the advent of BPA toxicity those replacements were not really scientifically sound. The dentists had secondary motives to do them, financially for two reasons, the initial replacement and the future replacements as composites tend to last half as long, leak and cause further issues down the road like root canals...

Point being that regardless of these drawbacks most modern dentists don't offer amalgams anymore at all because they're too cheap and last too long, and they literally have forgotten how to do them. This is undoubtedly the future for rim brakes.


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## Alex_Simmons/RST (Jan 12, 2008)

mambo said:


> I couldn't have said it better myself!
> 
> I'd add one caveat - when they are just as light!


It's the 0.012m^2 CdA penalty over standard rim brakes (not even aero rim brakes) that puts me off their use for road racing more than a few grams of extra weight ever will. Who the hell wants to add more than 10W to their power demand just to ride at same speed?

I'm not anti disk brake at all. Just use them where it's appropriate, that's all.


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## Special Eyes (Feb 2, 2011)

Is that technobabble for wind resistance or rotating mass?


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## Alex_Simmons/RST (Jan 12, 2008)

Special Eyes said:


> Is that technobabble for wind resistance or rotating mass?


Air resistance. 

The rotating mass difference of various typical wheel options is negligible on performance / energy demand, even in the hardest of accelerations.


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## Special Eyes (Feb 2, 2011)

That's what I thought. So, you believe that the disc brake hardware itself adds to the air resistance? Of course, any additional object or surface will, but this is not a lot of stuff we're talking about.


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## Alex_Simmons/RST (Jan 12, 2008)

Special Eyes said:


> That's what I thought. So, you believe that the disc brake hardware itself adds to the air resistance? Of course, any additional object or surface will, but this is not a lot of stuff we're talking about.


Well that's what was found when two otherwise identical road bike set ups were tested at the San Diego low speed wind tunnel. Only difference was one was fitted with the disk brake set up, the other with standard rim brake set up.

The data was shown in this story in which the author seems to have misunderstood the significance of the aero drag data. An average additional air drag of 120 grams over all yaw angles, worse with cross wind on drive side than non drive side, but worse at all yaw angles compared with rim brake.


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## Special Eyes (Feb 2, 2011)

OK I read the report. A bit old even in this very new world of discs. The discs they tested are no longer on the market. The rim brakes they used were mounted behind the fork, unlike nearly all rim front brakes in use. They never mentioned anything about the cabling routing or the hydraulic reservoir for the discs. Aero design parameters are not my engineering expertise (I do have other extensive engineering experience) but I have the feeling that even with this test, 120 grams of drag is pretty small. I respect controlled condition comparisons, but I'd want to see newer units tested, like Shimano's current road disc with integrated lever reservoir compared to Dura Ace or Sram rim calipers, both with internal cable routing. My gut feeling is that I would never actually detect a difference in my daily riding between each setup. A second water bottle in it's cage may have the same effect, or a long sleeve jersey compared to a short sleeve, or even just having your jersey zipper halfway down for ventilation.


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## MMsRepBike (Apr 1, 2014)

Camilo said:


> I'll be interested to see the day when a disc wheel can be as light as a rim brake wheel of a similar quality build ..... and that a disc frame and fork can be as light as a similar quality rim brake frame and fork... and that disc calipers can be as light as road calipers (maybe already? I have no idea).


Yeah, pretty much now. And we haven't even started the whole disc brake revolution yet. Just take a look at BMC and their Grandfond GF01. Both the normal and the disc brake versions have identical geometry. Both are made from the same materials, same sizes, blah blah. One is disc and one is rim brakes. The disc brake bike, entire bike, as sold on our showroom floor is a whopping 9 ounces heavier than the rim brake version. Oh, and the groupset for both is Dura-Ace Di2, no differences there.

So 9 ounces. I'm pretty sure that's not that big of a deal. I'm also pretty sure that soon they can get that down to 0 ounces if they want.


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## Alex_Simmons/RST (Jan 12, 2008)

Special Eyes said:


> OK I read the report. A bit old even in this very new world of discs. The discs they tested are no longer on the market. The rim brakes they used were mounted behind the fork, unlike nearly all rim front brakes in use. They never mentioned anything about the cabling routing or the hydraulic reservoir for the discs. Aero design parameters are not my engineering expertise (I do have other extensive engineering experience) but I have the feeling that even with this test, 120 grams of drag is pretty small. I respect controlled condition comparisons, but I'd want to see newer units tested, like Shimano's current road disc with integrated lever reservoir compared to Dura Ace or Sram rim calipers, both with internal cable routing. My gut feeling is that I would never actually detect a difference in my daily riding between each setup. A second water bottle in it's cage may have the same effect, or a long sleeve jersey compared to a short sleeve, or even just having your jersey zipper halfway down for ventilation.


One man's pretty small is another man's highly significant.

120 grams of drag means you need another ~12W to ride at same speed. It's enough for a sprinter to lose a close sprint or to waste valuable energy when you are doing everything in your power to save effort. 

That sort of saving is what elite riders spend hours and thousands of $ to reduce from tunnel testing.

When you are nearing peak fitness, 12 extra watts can takes months of hard work to attain.

Anyway, I'm only talking about the issues for maximal performance. For everyone else, it comes down to price, reliability, serviceability, and whether you can turn up at your local race and not get turned away.


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## DrSmile (Jul 22, 2006)

MMsRepBike said:


> So 9 ounces. I'm pretty sure that's not that big of a deal. I'm also pretty sure that soon they can get that down to 0 ounces if they want.


9 ounces is more than an entire rim brake set weighs! For any weight weenie 9 ounces is an absolutely huge amount of weight. I don't consider myself a weight weenie but 9 ounces is a lot even for me! My figure was 300 grams, so you and I agree on the amount at least. The standard reply to anyone who builds a light disc bike is "It could even be 3/4 of a pound lighter without those brakes..."


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## Camilo (Jun 23, 2007)

MMsRepBike said:


> Yeah, pretty much now. And we haven't even started the whole disc brake revolution yet.


Yea, I'm waiting until it's "good enough" by my personal criteria. I'm not an early adopter generally anyway.



> Just take a look at BMC and their Grandfond GF01. .... So 9 ounces. I'm pretty sure that's not that big of a deal. I'm also pretty sure that soon they can get that down to 0 ounces if they want.


Like he says below, 



Alex_Simmons/RST said:


> One man's pretty small is another man's highly significant.
> 
> 120 grams of drag means you need another ~12W to ride at same speed. It's enough for a sprinter to lose a close sprint or to waste valuable energy when you are doing everything in your power to save effort.
> 
> ...


I agree totally with this - the differences are meaningful for folks competing at the peak of their ability. I also agree that for most clear thinking cyclists, the weight and drag should be considered meaningless. 

But, in the general marketplace, the reality is that if two framesets (frame and fork) are compared and one is 250 grams lighter than the other, that's considered to be a quite large difference. Not saying it's right, but that's the way it is. Let's say 75 of that is in the fork and 175 in the frame. An 825 gram frame is viewed as quite a bit lighter than a 1,000 one and commands quite a bit more money. Same for a 400 gram fork compared to a 325 gram one.

For me, I'll go back to the list of simple criteria i listed earlier. I have no reason to compromise any of them, no matter how trivial, because the _need_ for a disc system is just not there for me. If every thing on my criteria list was met, then I'd probably make my choice based on looks, because the braking function would be a minor factor at best. But I'll be in line to try them out and will admit it if I end up being wrong!


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## danl1 (Jul 23, 2005)

MMsRepBike said:


> They will. Why? Carbon wheels.
> 
> Seems everyone wants carbon wheels and let's be honest, they suck at braking down mountains and such. Plus who wants to put that much stress on carbon by rim braking on it?
> 
> ...


This is an interesting state of affairs. We "need" carbon rims for weight savings and aerodynamics. But they brake like crap. So we add heavier hubs, and discs, and more spokes (because of the braking torque load), and mechanical complexity, thus giving up all the advantages we thought we were getting with the carbon rims. 

While the course of the industry suggests against it, there are ways that the problems with carbon rims for braking could be mitigated - such as metal mesh composites in the brake track. That doesn't mean that there still isn't a market for discs - there are a set of applications where they are really useful. But for road race applications, there's still a legitimate use for rim brakes. 

Everyone that insists that it's an either-or proposition is missing is just wrong. Both technologies have their place.


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## velodog (Sep 26, 2007)

Lateral stiffness in a fork is a good thing when cornering, while vertical stiffness in a fork reduces ride comfort, and current forks can have both, lateral stiffness and vertical compliance. 

It seems to me that this vertical compliance would need to be compromised some to stand up to the stresses put on it from the use of the disk brake. The rim brakes are centered while the disk is exerting it's forces on just the one side creating twisting forces that aren't there with the rim brakes. A mountain bikes suspension fork, due to it's construction, can deal with these forces while a road bikes suspension is the vertical flex in the fork. Take away that flex and the ride comfort is compromised while adding nothing to the bikes ability to corner. 

Lateral stiffness and vertical compliance, that's what is engineered into all these high end frames, so why would we be disregarding those same things in the fork.


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## pushstart (Feb 5, 2012)

This is a surprisingly good discussion of the merits and tradeoffs. Usually these threads just devolve into people regurgitating the arguments they read about braking inequality and slicing riders with rotors, so pleasant to read such good counter arguments.

I love my disc-brake road bike, but at 17lbs 3oz (60cm Sram Force + trp spyre build) it is not light. In my case, the disc brakes are probably adding close to 1lb (mechanicals, yokozuna housing, 28h wheels, ~200g penalty in frame + fork weight etc.) . For me it is worth it, no question, but the weight difference is significant when you consider the % of the bike weight. I am sure we will see this drop as the technology progresses. Of course technologies like di2 have also caught on despite a (small) weight penalty.

They definitely do make carbon wheels wonderful, but the point about *needing* carbon and then *needing* disc brakes because carbon braking sucks is quite right. It is a bit silly. But disc brakes are a really great braking technology and I for one can't see myself buying a rim-brake bike again.


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## Special Eyes (Feb 2, 2011)

I suppose I should have added that I am not a racer and my slack acceptance of additional grams here and there reflect my views. When 20 day stage races are won by less than 30 seconds, then it sure adds up to every gram. That's just not me. I still like to ride fast, though!

I ordered a Colnago CX Zero Disc this week. May have to change my handle….


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## tom_h (May 6, 2008)

*Specialized Tarmac disc brakes*

Maybe it's Specialized's way of trying to lock you in to their proprietary components, but here:
Specialized Tarmac Disc and new rim-brake Tarmac released - BikeRadar

they claim there are substantial design conflicts when trying to mate 135mm disc hubs onto a short chainstay road race bike.

Specifically they claim the Shimano and SRAM guidelines (420mm min chainstay) conflict with a road race bike's typical 405 mm stays.

The Specialized "solution"?

Wheels that move the cassette inboard, to maintain the required chain angles. The downside, is that a rear wheel with closer-spaced flanges will have less lateral stiffness.

Doesn't seem a good tradeoff to me.

Discs may have more appeal on "endurance" style road bikes, like Specialized's own Roubaix models. 

But on road race optimized bike frames like Tarmacs, _used as intended -- ie , Racing! -- _discs dont make much sense to me.

Makes even less sense on an "aero" road race bike like the Venge, yet people are talking about a hypothetical disc Venge
http://forums.roadbikereview.com/specialized/calls-venge-disc-brakes-323229.html


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## Fredrico (Jun 15, 2002)

Waspinator said:


> No offense, dude, but you really don't understand the purpose of anti-lock brakes, do you. They weren't developed to help people 'modulate' their braking. They were developed to prevent the wheels from locking and the car from sliding out of control in an emergency situation when the driver invariably panics and slams the brakes down. And when I say invariably, I mean invariably. "Emergency" may have slightly different meanings depending on the quality of the driver, but ALL drivers would, if scared enough, slam on the brakes and lock the wheels in the face of impending danger. Yes, the designer of these ABS brakes (who are a lot smarter than you and me) and the governments that mandate them know full well that you and I are as 'ham-fisted' as anyone else in a true emergency.
> 
> Not only that, disc brakes aren't made for better modulation. In fact, modulation on disc brakes is markedly worse, and understandably so. They offer better performance in wet conditions and that's pretty much it. As for increased "stopping power"...... pure rubbish - whatever mechanical advantage that is gained by closer proximity between stopping surfaces on a disc brake is almost certainly negated by the mechanical advantage rim brakes have by clutching at a wider radius.


Tell it like it is, Waspinator.  The truth, folks, plain and simple. :yesnod:

A reviewer in Road Bike Action wrote a critique on some disc brakes on a fancy carbon touring bike he test rode. He found the discs disappointing on fast downhills. I believe he said they faded worse than good rim brakes. Maybe it was the heat on those rotors softening up the pads or whatever. He also speculated about the fact a rim brake is nothing less than a very large disc. As you say above, the bigger the better! Certainly for modulation! And heat dissipation.

Mountain biking and commuting in snow, sure, discs are great. But for road racing? Ok, maybe for carbon rims, if that's what ya gotta have.

Has anyone successfully trued a disc inadvertently bent when putting on the wheel for example? I've seen some in the shop. A half millimeter off and they rub the pads! We always have to replace them. I guess the discs wouldn't get bent in a crash, but if they did, forget it.

So far, IMHO, disc brakes are another marketing gimmick by the folks who brought us Grand Fondo bikes (more upright riding for old geezers with too much money), and compact cranks.


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## SwiftSolo (Jun 7, 2008)

This is the same question mountain bikers were asking 12 years ago. Most people thought they had no chance of ever catching on. Today you'd be hard pressed to find a high end mountain bike without them.

Granted, road bikers are a bit different. They'd still be riding bikes with friction shifters on the down tubes if not for mountain biking.

I have a road bike with shimano hydro disc brakes and there is no doubt that they are far superior in modulation, predictability, and power. The levers can be set up with half the clearance to the drops since they are self adjusting and don't require the clearance or travel that typical rim bakes calipers/levers/pads require.

Don't mistake this as assurance that they will quickly take over. For whatever reason, there are far too many Luddites in road biking, and without ever trying them, they'll be the x-spurts on the subject. Those with hydro disc brakes will be just as happy if only our riding partners convert.


Waspinator said:


> I can see their benefit for offroading, but for road?


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## Special Eyes (Feb 2, 2011)

Swift, what bike did you end up with?


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## Mr Evil (Aug 12, 2011)

Fredrico said:


> ...Has anyone successfully trued a disc inadvertently bent when putting on the wheel for example? I've seen some in the shop. A half millimeter off and they rub the pads! We always have to replace them...


Grab the rotor with an adjustable spanner and tweak it in the desired direction. It might seem like it wouldn't be possible to straighten a steel disc, but actually it's remarkably easy. Hopefully they will start making both discs and pads with chamfered edges so that replacing the wheel less likely to cause this in the first place.



Fredrico said:


> ..I guess the discs wouldn't get bent in a crash, but if they did, forget it...


Rims might also become irreparably bent in a crash, but a bent wheel is more likely to remain rideable with disc brakes.


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## aclinjury (Sep 12, 2011)

nealric said:


> I feel like most of the anti-disc crowd does not ride mountain bikes. For me, the improved feel is worth it by itself. I've also had a heat-related flat on a long downhill- one of those is enough.
> 
> Weight really won't be that much of an issue. Wouldn't be surprised if disc bikes can get into the sub 15 lb range.


I ride mtb bike too. Out on the dirt trail, modulation means jack. Modulation to most moutain bikers means locking the rear wheel up and skidding around corners and in the process cause trail errosion. Lack of skill cannot be made up for by equipment. Then I also see guys on old mtb with v-brakes who don't skik.

I've descend 4 miles on the road averaging 10% with lots of 15-20% segments on my roadbike with aluminum wheels with absolute zero problem. But on this same descent, I know of at least one guy using carbon wheels who have smoked his rim (but short of a blowout). My opinion is that carbon wheel is the problem, not rim brakes.


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## SwiftSolo (Jun 7, 2008)

I bought the cannondale synapse hi-mod disc dura ace. I really like it now that the FSA slk seat post has been replaced.


Special Eyes said:


> Swift, what bike did you end up with?


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## SwiftSolo (Jun 7, 2008)

I think the "need" may be based on the definition of MTB. I don't think anyone who does serious mountain biking and who has owned a bike with hydro disc brakes is likely to ever go back.


tlg said:


> Yes, it's inevitable. Whether it "catches on" or is forced on by manufacturers, it's going to eventually happen.
> 
> I just looked at Trek & Specialized websites. Neither offer a MTB with rim brakes on a bike over $600. WTF. Most people who MTB do not need disc brakes. Yet that's all they are offered.
> 
> I predict the exact same to happen with road bikes.


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## SwiftSolo (Jun 7, 2008)

JetSpeed said:


> No. It's a fad like speckled bar tape.


Or like indexed shifting or more than one gear for that matter!


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## SwiftSolo (Jun 7, 2008)

For flatlanders, I can't see discs playing a significant roll unless it is a traditionally rainy area. However, there's a segment of road bikers who live for riding in the mountains and steep climbs and descents. The predictability of hydro discs provides far more security when charging into hairpins than cantilevers. Most significant mountains create their own weather and that is often combined with those who do much riding during snow melt when the roads (and rims) are wet.

A really big advantage is the ability to have the resting position of the brake levers very close to the drops since brake wear is self adjusting and required brake lever travel is typically less than half of that of cantilevers. Both shifting and braking from the drops is much easier.

Finally, when combined with Di2, there are no cables or housings that ever have to be replaced (or the associated bar tape). This is a big issue for those of us who ride in wet conditions a lot.


tlg said:


> I run XTR V's and Avid Single digits on one of my MTB's. I could easily put myself OTB if I wanted to. Stopping power is definitely not the issue. Most people don't need that stopping power while putzing down some singletrack.
> 
> A lot of people don't ride when it's wet. So they don't need great performance when wet.
> 
> ...


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## SwiftSolo (Jun 7, 2008)

Those bass tard capitalists!

I know that whenever I'm climbing long 14% grades, I long for those non-compact chainrings and the days before I was forced to buy them. Sonz-a-biaches!


Fredrico said:


> So far, IMHO, disc brakes are another marketing gimmick by the folks who brought us Grand Fondo bikes (more upright riding for old geezers with too much money), and compact cranks.


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## tom_h (May 6, 2008)

SwiftSolo said:


> Those bass tard capitalists!
> 
> I know that whenever I'm climbing long 14% grades, I long for those non-compact chainrings and the days before I was forced to buy them. Sonz-a-biaches!


BTW, couple yrs ago, the silver medalist in the SoCalif cat3 road race championships was riding a 50/34 compact.

IMO, there's a big disconnect between a cyclist's belief they "need" a standard 53/39 crank vs their actual W/kg capability (unless they live in pancake flat FL or similar).


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## velodog (Sep 26, 2007)

aclinjury said:


> My opinion is that carbon wheel is the problem, not rim brakes.


Yeah, but, carbon rims are Kool while rim brakes are for dinosaurs.


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## Shegens (Sep 14, 2013)

I wish I had them on my hybrid. When I bought my granddaughter's Trek MTB there were two models, one with disc brakes and one with regular brakes. I couldn't see the extra cost for disc on a bike that might be ridden six times a year so she got the regular brakes.

I know I gripe about all these hills but I actually prefer climbing up more than coming down. I don't like a lot of speed on the downhill and tend to use my brakes more than I like. It would probably be better with disc brakes. If I ever invest in another bike it will have disc brakes. My local Trek dealer said I would LOVE them but I have never test ridden a bike with them.


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## BikeLayne (Apr 4, 2014)

.....
.


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## Trek_5200 (Apr 21, 2013)

velodog said:


> Yeah, but, carbon rims are Kool while rim brakes are for dinosaurs.



Except way to many posts say alloy provides a better braking surface and why Shimano does Carbon with an alloy braking strip(best of both worlds). I don't think there's too much argument that carbon doesn't brake as well when wet, and the pads cost more to replace.


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## velodog (Sep 26, 2007)

BikeLayne said:


> That's one way to look at it. Another is carbon rims are not fully recyclable and in most areas there is no recycling of carbon products at all. The damaged carbon rim then goes into the landfill for thousands upon thousands of years (old school, dinosaur thinking). However aluminum rims can go into the scrap metal and can be fully recycled into another rim, a bike or a bridge (Kool).


Wait a minute.

So you're saying that all us dinosaurs are forward thinking Kool Kats while all the Kool Kids with the carbon bits have their heads stuck in the sand and are destroying the environment.

You got me all Kornfused.


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## MoPho (Jan 17, 2011)

BikeLayne said:


> That's one way to look at it. Another is carbon rims are not fully recyclable and in most areas there is no recycling of carbon products at all. The damaged carbon rim then goes into the landfill for thousands upon thousands of years (old school, dinosaur thinking). However aluminum rims can go into the scrap metal and can be fully recycled into another rim, a bike or a bridge (Kool).



SPECIALIZED CARBON FIBER RECYCLING PROGRAM

Trek Bicycle begins carbon fiber recycling program


And of course there is always this option 











.


.


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## h2oxtc (May 16, 2012)

SwiftSolo said:


> For flatlanders, I can't see discs playing a significant roll unless it is a traditionally rainy area. However, *there's a segment of road bikers who live for riding in the mountains and steep climbs and descents*. The predictability of hydro discs provides far more security when charging into hairpins than cantilevers. Most significant mountains create their own weather and that is often combined with those who do much riding during snow melt when the roads (and rims) are wet.
> 
> A really big advantage is the ability to have the resting position of the brake levers very close to the drops since brake wear is self adjusting and required brake lever travel is typically less than half of that of cantilevers. Both shifting and braking from the drops is much easier.
> 
> Finally, when combined with Di2, there are no cables or housings that ever have to be replaced (or the associated bar tape). This is a big issue for those of us who ride in wet conditions a lot.





DrSmile said:


> I despised nothing more than the bike vans passing me as I rode up Haleakala. It was a nice feeling flying by all the tourists on MTBs on the way back down though!
> 
> Haleakala is a 10,000 ft descent... and no, I didn't need discs to go down! :devil:
> 
> *I will admit however that my hands were killing me* descending Kaloko Drive on the Big Island.


I live in an area where every ride worth riding involves hills. I have 4 road bikes, one with canti's (Avid Ultimate), two with calipers (DuraAce and Athena) and one with Avid Road SL discs. I wouldn't consider putting discs on all of my bikes, but they sure are sweet. Whether they "catch on" or not doesn't really matter to me, I love mine.


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## SwiftSolo (Jun 7, 2008)

Right on Dude! That's why neither disc brakes nor hydraulic brakes ever caught on in automobiles. It's "common knowledge" that mechanical brakes are much much more better!


Waspinator said:


> Dude, disc brakes don't allow for better modulation. They are worse in this respect. This is common knowledge.
> 
> And it makes sense why. The pad movement for braking occurs over a much smaller distance. A rim brake moves over a millimeter in order to brake. A disc brake moves maybe a half millimeter? It's much harder to 'modulate' the movement of something when the increments you have to move it in order to modulate become so small.


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## BikeLayne (Apr 4, 2014)

......


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## BikeLayne (Apr 4, 2014)

.....


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## aclinjury (Sep 12, 2011)

Alex_Simmons/RST said:


> One man's pretty small is another man's highly significant.
> 
> 120 grams of drag means you need another ~12W to ride at same speed. It's enough for a sprinter to lose a close sprint or to waste valuable energy when you are doing everything in your power to save effort.
> 
> ...


You're preaching to a bunch of bearded old men who take great pride riding a double century thru rain and snow at zone 1 and 60 rpm. Telling them about 12W saving at zone 1, ugh,.. not gonna compute.


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## DrSmile (Jul 22, 2006)

aclinjury said:


> You're preaching to a bunch of bearded old men who take great pride riding a double century thru rain and snow at zone 1 and 60 rpm. Telling them about 12W saving at zone 1, ugh,.. not gonna compute.


<---- stroking his grey beard reading this.


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## Notvintage (May 19, 2013)

88 rex said:


> 1) Disc frames are not heavier.


Wrong. Absolutely disc frames are heavier. The mounting posts on the chainstay and front fork require significant reinforcement from the additional stresses, moreover it's all heavier. The wheels need to be much stronger, the fluid. . then, add in they are very un-aerodynamic. And when you look at the bikes now, they are lighter and are also incorporating aerodynamic features. 
Why have all these benefits (light weight and aerodynamic) then turn your bike into a sled?


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## ozzybmx (Jun 23, 2013)

Notvintage said:


> Wrong. Absolutely disc frames are heavier. The mounting posts on the chainstay and front fork require significant reinforcement from the additional stresses, moreover it's all heavier. The wheels need to be much stronger, the fluid. . then, add in they are very un-aerodynamic. And when you look at the bikes now, they are lighter and are also incorporating aerodynamic features.
> Why have all these benefits (light weight and aerodynamic) then turn your bike into a sled?


So do rim brake frames have reinforced/extra carbon lay up around the brake bridge area ?


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## SwiftSolo (Jun 7, 2008)

For a reality check:
I currently have a Tarmac s-works sl3 and a Cannondale synapse hi-mod dura ace disc. 

The SL3 has Zipp 303 tubulars (Paves), a thompson masterpiece seatpost, a carbon railed Arione saddle, Easton ec90 bars and campy super record 11 speed with EEbrakes. It weighs in at 14lbs 9 oz without the pedals.

The Cannondale hi mod has enve clincher wheels (Pave clinchers) Di2, a thompson elite seatpost (heavier than the Masterpiece), Cannondales standard carbon bars, and Shimano hydro disc brakes and levers (only the deraileurs wiring, and battery are Dura-ace). It weights in at 16 lbs and 5 oz without pedals.

With Tubular disc brake wheels I can reduce the weight of the cannondale by 13 ozs and likely another 110 grams (4 ozs) on the handles bars and seatpost combined. That will take the Cannondale down to 15 lbs and 4 ozs, or 11 ozs heavier than the Tarmac. 

I'm guessing that di2 is heavier than campy super record by another couple of ozs (non electronic). I'm likely paying a total price of about 9 Oz or 250 grams in order to have hydo discs with the current non-dura ace shifters and brakes.

What have I gained with the hi-mod?
1. Far superior braking power, predictability, and modulation (adds up to superior control)
2. No more cables or housings of any kind on the bike
3. Far superior shifting (could have that without hydro discs but it is a weight consideration)
4. The ability to charge into curves deeper before applying the brakes (because of increased power combined with complete braking predictability)
5. Most important to me, the significant reduction of hand fatigue and arthritis flare-ups cause by the long, steep, hairpin laden descents of the climbs that I spend most of my riding time on. 

All of this comes at a time when wheels are becoming wider, tire compounds are getting stickier and tire size myths have been debunked, leading to larger contact patches with better friction. 

Do consider the changes that do give some of the weight back. The seat stays are lighter because they no longer have the bridge nor are they beefed up to take the loads of cantilevers. Cables and housings are gone (eliminates some drag). Things are mostly run internally and I suspect that very soon, even the minimal external hydro hose exposure with be cleaned up.

You are correct that the brakes discs do add some drag in crosswinds but I suspect that the brake calipers are about a push with cantilevers.

In summary, I think the real penalty is about 9 ozs weight net. Frontal drag differences are likely insignificant. I realize that for some, weight and wind resistance are everything. Those folks can realize monumental gains by riding a fixie (should be able to get down to 11 or 12 pounds).


Notvintage said:


> Wrong. Absolutely disc frames are heavier. The mounting posts on the chainstay and front fork require significant reinforcement from the additional stresses, moreover it's all heavier. The wheels need to be much stronger, the fluid. . then, add in they are very un-aerodynamic. And when you look at the bikes now, they are lighter and are also incorporating aerodynamic features.
> Why have all these benefits (light weight and aerodynamic) then turn your bike into a sled?


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## MoPho (Jan 17, 2011)

Notvintage said:


> Wrong. Absolutely disc frames are heavier. The mounting posts on the chainstay and front fork require significant reinforcement from the additional stresses, moreover it's all heavier. The wheels need to be much stronger, the fluid. . then, add in they are very un-aerodynamic. And when you look at the bikes now, they are lighter and are also incorporating aerodynamic features.
> Why have all these benefits (light weight and aerodynamic) then turn your bike into a sled?



Why have all those "benefits" (light weight and aerodynamic) and then add a seat bag, pump, water bottles, computers, di2 batteries and a fat ass who hasn't spent any time in a wind tunnel perfecting their riding position to take advantage of said aero frame?

Probably a good 98% (+/-) of riders make little to no use of any weight or aero advantages, we all can't be elite pros like Aclinjury you know! 


Even if racing it is a bit silly of an argument since many race bikes need ballast to meet the minimum weight requirements and if aero was so important why aren't all the pros riding aero bikes in competition? Surely every race is won on an aero bike, right? 
All this new technology you speak of and average speeds on the TDF haven't increased in the past 20 years, hmmm.......


It's funny how the anti-disc crowd argues that it's just crap that the manufactures are trying to sell us and then in the next breath argue weight and aero, which is also just crap that the manufacturers try and sell us. You say you don't need disc brakes, well you don't need aero or light weight either! 



.


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## eriku16 (Jul 27, 2011)

tom_h said:


> BTW, couple yrs ago, the silver medalist in the SoCalif cat3 road race championships was riding a 50/34 compact.
> 
> IMO, there's a big disconnect between a cyclist's belief they "need" a standard 53/39 crank vs their actual W/kg capability (unless they live in pancake flat FL or similar).


One thing for sure, compacts did not come about from racing. Compacts came about because of the need to sell bikes with racing geometry to the masses who don't have the fitness. Just like frames with tall head tubes for the less flexible. Compacts are (almost) the new triple and would not exist if not for the number and wider range cogs today.


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## aclinjury (Sep 12, 2011)

SwiftSolo said:


> For a reality check:
> I currently have a Tarmac s-works sl3 and a Cannondale synapse hi-mod dura ace disc.
> 
> The SL3 has Zipp 303 tubulars (Paves), a thompson masterpiece seatpost, a carbon railed Arione saddle, Easton ec90 bars and campy super record 11 speed with EEbrakes. It weighs in at 14lbs 9 oz without the pedals.
> ...


couple comments.

The size of a contact patch does not play into the equation determining friction. It is the compound of the rubber that determines friction between the tire and the road. Too many folks keep saying larger contact patch means more friction, and this is incorrect. Rubber compound determines friction.

The Cdale hi-mod frame is definitely lighter than the SL3, by at least 100g. You didn't account for this. Not that you would care about the grams.


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## Mr Evil (Aug 12, 2011)

aclinjury said:


> ...The size of a contact patch does not play into the equation determining friction. It is the compound of the rubber that determines friction between the tire and the road. Too many folks keep saying larger contact patch means more friction, and this is incorrect. Rubber compound determines friction...


I remember having this argument when I put wider tyres on my car to improve traction, and some people applied their knowledge of ideal physics to conclude that it wouldn't work. The reason why it _does_ work is the non-linear behaviour of tyres, which means that traction really does increase with contact area.


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## Fredrico (Jun 15, 2002)

tom_h said:


> BTW, couple yrs ago, the silver medalist in the SoCalif cat3 road race championships was riding a 50/34 compact.


He could have taken gold with a standard crank! :lol:


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## mambo (Jul 29, 2012)

SwiftSolo said:


> For a reality check:
> 
> 
> In summary, I think the real penalty is about 9 ozs weight net. .


That's enough for me not to want disc brakes. As going downhill is a matter of skill and cojones, I do not think I could go any faster with discs anyway, plus I never felt a lack of stopping power or modulation with standard rim brakes anyway. Add to that that the pain in the butt of avoiding brake rub when you have to remove the wheel to repair a flat and there is no argument that will convince me to use disc brakes unless rim ones become obsolete.

The area on the forks where rim brakes are fitted has to be reinforced anyway.


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## Fireform (Dec 15, 2005)

Because we're all just clamoring for heavier, less aero, less responsive bikes.


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## SwiftSolo (Jun 7, 2008)

Yep,
Those Freds using compacts in some stages in the Giro are not real racers--you know-- like you! 

Do you ever have to use your 39 on Zoncolan or do you use your fixie with 53/11?


eriku16 said:


> One thing for sure, compacts did not come about from racing. Compacts came about because of the need to sell bikes with racing geometry to the masses who don't have the fitness. Just like frames with tall head tubes for the less flexible. Compacts are (almost) the new triple and would not exist if not for the number and wider range cogs today.


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## Special Eyes (Feb 2, 2011)

Brake rub? If your brakes are properly installed and setup, there will no rub after the wheel is put back in the frame, whether rim or disc brakes.

*"In summary, I think the real penalty is about 9 ozs weight net. .
That's enough for me not to want disc brakes."*

Water weighs .926 ounces per fluid oz of volume. A small (21 fluid oz.) water bottle holds 19.45 ounces of water in weight (NOT counting the bottle). Therefore, 9 oz of increased weight of your bike equals less than half of a small water bottle of water. 

Are you racing? That might be the only time that small a difference might be noticed.


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## Notvintage (May 19, 2013)

Marc said:


> Non-round chainrings have never really caught on throughout their dozens of iterations over the last 100+ years with every new one claiming to fix all the fallacies of the old.


I love my Rotor rings.


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## aclinjury (Sep 12, 2011)

Mr Evil said:


> I remember having this argument when I put wider tyres on my car to improve traction, and some people applied their knowledge of ideal physics to conclude that it wouldn't work. The reason why it _does_ work is the non-linear behaviour of tyres, which means that traction really does increase with contact area.


There are lots of reasons why a high performance sportscar would use a wider tire. But to get more friction because of a bigger contact patch is not the core reason why they use wider tires. And note, my comment was in response to the discussion of "friction", not traction.

(btw if there was bad technical explanation of a physics issue on wiki, the link you gave would be it. At least put some equations up there and let the readers see what you're really talking about and to what extent. Why did anyone even bother writing it. Sorry it irks me a bit when I see a physics explanation dumb down so much it's useless. But I guess we're living in a world of 5-sec sound bites.)

now truth is yes in practice, friction coefficient does change (minimally) with a larger tire and the reason could be better heat dispersion to the ability of the tire to hold its shape under load. But it's pretty meaningless compared to the type of rubber compound used. If tire size (and tire patch) was all there was to the story of friction (and related traction), then we'd have cruisers with their ridiculously fat 220-240 tires out gripping a small motorcycle with their 120-160 sized tires, and more so when compared to skinny bicycle tires, right? 

But it may surprise you that there are some skilled and experience cyclists riding 23mm tires who can overtake motorcycle cruisers around corners, sometimes easily too, and in some cases even overtake a 1000cc sportsbike.. around corners. Bottom line is, in bicycle application, whether it's a 23mm or 25mm tire, if you want grip, then SOFT rubber is the dominant factor, not patch size, because the patch size difference between a 23mm and a 25mm tire is almost nonexistant


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## obed (Jan 12, 2014)

rubber compound is the answer for traction...
that is why motorcycles use different compounds for different track situations, and of course temperature matters, that is why they use tire warmers to bring the tires up to temp before the race starts...contact patch for a motorcycle in full lean is pretty damn small too.


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## aclinjury (Sep 12, 2011)

obed said:


> rubber compound is the answer for traction...
> that is why motorcycles use different compounds for different track situations, and of course temperature matters, that is why they use tire warmers to bring the tires up to temp before the race starts...contact patch for a motorcycle in full lean is pretty damn small too.


yep. And to add, it's pretty common for a racer to use softer rubber up front and harder rubber out back. I'd bet that the combined contact patch area of a racing motorcycle at full lean is much smaller than the combined area of the 4 tires of a passenger car, but the moto can pull a higher G. That's sticky rubber for ya.

On my bicycle, I like to use 23-25mm wide tire, that is SOFT and supple, for maximum front end feel and grip. For the rear, I go with a wider 25mm tire in harder compount (eg, Specialized Armadillo, Michelin Pro 4 Endurance) for maximum wear resistance.


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## Mr Evil (Aug 12, 2011)

aclinjury said:


> There are lots of reasons why a high performance sportscar would use a wider tire. But to get more friction because of a bigger contact patch is not the core reason why they use wider tires...


Lots of reasons, but size (and shape) of the contact patch is still one of them.



aclinjury said:


> ...And note, my comment was in response to the discussion of "friction", not traction...


Traction is a function of friction, but if you want to be pedantic, then _traction_ is increased with a larger contact patch partly because _friction_ increases. There are other reasons why a larger contact patch results in increased traction too, e.g. it conforms better to the road surface (which as I recall from when I was looking into this for my car is the most significant reason why wider tyres improve cornering, for cars at least).



aclinjury said:


> ...btw if there was bad technical explanation of a physics issue on wiki, the link you gave would be it. At least put some equations up there and let the readers see what you're really talking about and to what extent. Why did anyone even bother writing it. Sorry it irks me a bit when I see a physics explanation dumb down so much it's useless. But I guess we're living in a world of 5-sec sound bites...


You sound pretty knowledgeable about the issue, so perhaps you could improve the article?



aclinjury said:


> ...But it may surprise you that there are some skilled and experience cyclists riding 23mm tires who can overtake motorcycle cruisers around corners, sometimes easily too, and in some cases even overtake a 1000cc sportsbike.. around corners...


I don't believe this would happen if both vehicles were cornering at their limit. Motorcyclists can lean over way more than I've ever seen a cyclist do, which permits higher cornering speeds.



aclinjury said:


> ...if you want grip, then SOFT rubber is the dominant factor...


Sure, but even then, if you have sticky rubber then a larger contact patch means more of it adhering (another aspect of traction that is not friction) to the road.


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## LVbob (Mar 24, 2014)

eriku16 said:


> One thing for sure, compacts did not come about from racing. Compacts came about because of the need to sell bikes with racing geometry to the masses who don't have the fitness. Just like frames with tall head tubes for the less flexible. Compacts are (almost) the new triple and would not exist if not for the number and wider range cogs today.


Do I sense a judgement or two in there. I guess cycling is reserved for the elite few.


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## Trek_5200 (Apr 21, 2013)

eriku16 said:


> One thing for sure, compacts did not come about from racing. Compacts came about because of the need to sell bikes with racing geometry to the masses who don't have the fitness. Just like frames with tall head tubes for the less flexible. Compacts are (almost) the new triple and would not exist if not for the number and wider range cogs today.


I agree with that. Pros seldom use compacts except as a strategy for climbing segments in the the Giro or other similar races, however they immediately get taken off and replaced with non-compact for other segments. But you need to be careful. When people hear you attack their compacts, its' like attacking their manhood.


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## Trek_5200 (Apr 21, 2013)

SwiftSolo said:


> Yep,
> Those Freds using compacts in some stages in the Giro are not real racers--you know-- like you!
> 
> Do you ever have to use your 39 on Zoncolan or do you use your fixie with 53/11?


Again big difference in a pro using a compact for a particular stage as a form of strategy and Joe bike rider buying one because he can't climb otherwise.


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## DrSmile (Jul 22, 2006)

May I point out that "some of us" are down on power not because we are out of shape, but rather just because we are old. Your max power definitely goes down after age 40 (non-enhanced at least).

I'm not speaking for myself btw, because I am old AND out of shape.


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## Trek_5200 (Apr 21, 2013)

DrSmile said:


> May I point out that "some of us" are down on power not because we are out of shape, but rather just because we are old. Your max power definitely goes down after age 40 (non-enhanced at least).
> 
> I'm not speaking for myself btw, because I am old AND out of shape.


I'm sure that's true on some level, however I'm both running and cycling considerably faster than I did 20 years ago. The only difference I find now, is that training nutrition and sleep matter more. I also pulled up the NY Gran Fondo rankings by age group and there were some phenomenal finishers in the 50 year and 60 year plus categories.


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## LVbob (Mar 24, 2014)

Trek_5200 said:


> Again big difference in a pro using a compact for a particular stage as a form of strategy and Joe bike rider buying one because he can't climb otherwise.


It's surprising to me to see cyclists belittle other cyclists for the choices they make (or don't make as in when the bike you want only comes with a compact crank). Is cycling really so small that there is not enough room for both rim and disc brakes, both standard and compact cranks.

And why are some always judging in the first place? I find that most judgmental people are really insecure about themselves and need to look for "stuff" to prop themselves up.


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## Trek_5200 (Apr 21, 2013)

Actually, I think it's great that this option is available. It opens up cycling and terrain to people who wouldn't be able to enjoy it otherwise. I just believe everyone should be honest about it. I'm surprised at how sensitive people are about this.


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## SwiftSolo (Jun 7, 2008)

Consider that some of us actually live for climbing the long and steep while others live where freeway overpasses are the extent of their climbing. As complicated as it seems, the two situations call for different cogs and chain rings. 

Further consider that those who brag about having big gears usually have small units that they hope to compensate for. Just saying!


Trek_5200 said:


> I agree with that. Pros seldom use compacts except as a strategy for climbing segments in the the Giro or other similar races, however they immediately get taken off and replaced with non-compact for other segments. But you need to be careful. When people hear you attack their compacts, its' like attacking their manhood.


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## Fireform (Dec 15, 2005)

Trek_5200 said:


> Actually, I think it's great that this option is available. It opens up cycling and terrain to people who wouldn't be able to enjoy it otherwise. I just believe everyone should be honest about it. I'm surprised at how sensitive people are about this.


What the heck are you talking about? What terrain, exactly, is being opened up?


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## Whacked (Feb 14, 2011)

Anyone that uses wiki as a reference need to be smacked upside the head with a 2x4. seriously. reference wiki? What a joke.

And any issue with wind resistance or aerodynamic drag caused by disk rotors and cables... my sides hurt bad from laughing so hard.
Anything you may feel is all in your head. You will not notice any difference. In a wind tunnel hooked up to machines you can measure it. Practicality the difference is insignificant.


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## LVbob (Mar 24, 2014)

Trek_5200 said:


> Actually, I think it's great that this option is available. It opens up cycling and terrain to people who wouldn't be able to enjoy it otherwise. I just believe everyone should be honest about it. I'm surprised at how sensitive people are about this.


I've seen your posts littering many threads with condescension. And then there is that testosterone-fest thread that you started. You belittle others (including beginners like myself) to make up for your own inadequacies. At least that what it looks like from here. Fortunately, it's pretty clear that most people here don't take you seriously.


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## spdntrxi (Jul 25, 2013)

Trek_5200 said:


> Actually, I think it's great that this option is available. It opens up cycling and terrain to people who wouldn't be able to enjoy it otherwise. I just believe everyone should be honest about it. I'm surprised at how sensitive people are about this.


how many HC or cat1/2 climbs do you do ? I have Mt Diablo, Mt Hamilton, Mt Tam, Morgan Territory, Old La Honda and a whole host of others to tackle... I could do them with a 42T, but after a knee surgery.. my knees are thankful for the 34t


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## Trek_5200 (Apr 21, 2013)

spdntrxi said:


> how many HC or cat1/2 climbs do you do ? I have Mt Diablo, Mt Hamilton, Mt Tam, Morgan Territory, Old La Honda and a whole host of others to tackle... I could do them with a 42T, but after a knee surgery.. my knees are thankful for the 34t


If I had knee surgery, I would do what you are doing and ride compact. Cheers.


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## Special Eyes (Feb 2, 2011)

Uh, this thread was about disc brakes at one point..... What happened?


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## aclinjury (Sep 12, 2011)

Mr Evil said:


> Lots of reasons, but size (and shape) of the contact patch is still one of them.
> 
> 
> Traction is a function of friction, but if you want to be pedantic, then _traction_ is increased with a larger contact patch partly because _friction_ increases. There are other reasons why a larger contact patch results in increased traction too, e.g. it conforms better to the road surface (which as I recall from when I was looking into this for my car is the most significant reason why wider tyres improve cornering, for cars at least).
> ...


You have to remember the difference in contact patch between a 23mm and a 25mm tires is almost nil, so the argument of using a larger tire in the world of road racing bicycle for the purpose of additional friction is moot. Rubber compound is the dominant factor. Most cyclists do not come anywhere close, not even close, to the limit of their 23mm tire, yet they seem to buy into this notion that a 25mm tire (which has almost nil advantage in term of contact patch) suddenly give them more grip. Question, if they can't push the limit with a 23mm tire, what makes them think that they can now push the limit with a 25mm tire? Do they suddenly now know the limit of a 25mm tire that they didn't know from the 23mm tire?


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## Neb (Sep 8, 2012)

aclinjury said:


> You have to remember the difference in contact patch between a 23mm and a 25mm tires is almost nil, so the argument of using a larger tire in the world of road racing bicycle for the purpose of additional friction is moot. Rubber compound is the dominant factor. Most cyclists do not come anywhere close, not even close, to the limit of their 23mm tire, yet they seem to buy into this notion that a 25mm tire (which has almost nil advantage in term of contact patch) suddenly give them more grip. Question, if they can't push the limit with a 23mm tire, what makes them think that they can now push the limit with a 25mm tire? Do they suddenly now know the limit of a 25mm tire that they didn't know from the 23mm tire?


I actually don't know many cyclists that went for a larger tire to get more grip. Almost all that I've spoken to are doing it for comfort (including myself). Bigger tire and lower pressure results in more comfort with minimal change in rolling resistance.


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## Trek_5200 (Apr 21, 2013)

Neb said:


> I actually don't know many cyclists that went for a larger tire to get more grip. Almost all that I've spoken to are doing it for comfort (including myself). Bigger tire and lower pressure results in more comfort with minimal change in rolling resistance.


I spoke to my local bike shop about switching to 25mm. The answer I got back was that it could be done. Also asked how much of a difference I would notice in traction and comfort. The shop didn't think I would notice a huge difference and said if I was going that route wider tires would make more sense, which none of my bikes support, so I opted to forget the whole thing. On my particular frame(s) comfort isn't an issue, and during the months outside winter and based on my riding style, I don't push the bike enough to necessitate the switch either.

From what I've heard/read some of the advantages of the wider tires become more apparent on bad roads, hence the Roubaix use, and I avoid those roads as much as possible.


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## MMsRepBike (Apr 1, 2014)

MMsRepBike said:


> Having more braking power is never going to be an argument for disc brakes. Better control, yes. You will be very hard pressed to do a front wheel manual downhill on a road bike with rim brakes, I dare say you can't do it. But with disc brakes it's very much possible and has been done.


Brumotti - Road Bike Freestyle - YouTube

Nevermind. Rim brakes work just fine for that.


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## tlg (May 11, 2011)

Trek_5200 said:


> But you need to be careful. When people hear you attack their compacts, its' like attacking their manhood.


You've reached a new level of low. You weren't attacking peoples compacts in the other thread. You were directly attacking their riding abilities. What you specifically said was people who didn't ride 53/39 were not "_real cyclists_". 
Give it up, it's REALLY getting pathetic.


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## Notvintage (May 19, 2013)

Whacked said:


> Anything you may feel is all in your head. You will not notice any difference. In a wind tunnel hooked up to machines you can measure it. Practicality the difference is insignificant.


The difference between a 32 spoke box section rim and a decent aero-wheel can be at least a pound of drag. A rotor compatible hub, a rotor and caliper hanging off the bike? Like tubeless wheels this crap belongs in the woods on mountain bikes.


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## aclinjury (Sep 12, 2011)

Neb said:


> I actually don't know many cyclists that went for a larger tire to get more grip. Almost all that I've spoken to are doing it for comfort (including myself). Bigger tire and lower pressure results in more comfort with minimal change in rolling resistance.


plenty of people on RBR think going from a 23mm to 25mm gives them better, more confidence, in corners. The benefit is miniscule compare to getting a 23mm in softer rubber, AND practice the skill.

Me,, i think wider rim is more important than wider tire. 

and you don't want to put a too wide of a tire on a narrow 19mm wide rim. Sure if may be comfy in a straightline cruising.. the sidewall of the tire will roll or fold in a hard corner (this can happen if pressure is too low too). Wider tire is good, but predicated on using it with a wider rim.


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## Neb (Sep 8, 2012)

aclinjury said:


> plenty of people on RBR think going from a 23mm to 25mm gives them better, more confidence, in corners. The benefit is miniscule compare to getting a 23mm in softer rubber, AND practice the skill.
> 
> Me,, i think wider rim is more important than wider tire.
> 
> and you don't want to put a too wide of a tire on a narrow 19mm wide rim. Sure if may be comfy in a straightline cruising.. the sidewall of the tire will roll or fold in a hard corner (this can happen if pressure is too low too). Wider tire is good, but predicated on using it with a wider rim.


I run a wide rim + wide tire, with lower pressure. Makes crappy roads much more tolerable.

To take it to the max, I have a 41c tire lined up for my cx bike for gravel riding. I think that counts as a wide tire, right?


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## BikeLayne (Apr 4, 2014)

Special Eyes said:


> Uh, this thread was about disc brakes at one point..... What happened?


.....


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## Bill2 (Oct 14, 2007)

SwiftSolo said:


> Consider that some of us actually live for climbing the long and steep while others live where freeway overpasses are the extent of their climbing. As complicated as it seems, the two situations call for different cogs and chain rings.
> 
> Further consider that those who brag about having big gears usually have small units that they hope to compensate for. Just saying!


Well said!


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## BikeLayne (Apr 4, 2014)

.....


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## gregkcubed (Apr 14, 2009)

as a heavy guy, commuting in all weather on a bike with anywhere from 10-20 pounds of extra stuff on it, I can't wait to get disc brakes.

My current bike is a "touring" bike but the brakes suck so much, with any extra weight on it, it is dangerous to slow down. No it's not the pads, its not the wheels, it's just they don't stop very quickly with all that weight. If its wet outside, forget about it.

i see this discussion like this:
1. Road bike guys who like to go fast and aren't heavy - not discs.
2. MTB discs.
3. Touring discs.
4. Commuters, tossup. Discs if you ride in the rain or snow.
5. Veladromers & hipsters, no brakes.


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## vic bastige (Jan 22, 2004)

tom_h said:


> ... overweight Hawaii tourists on a "coast down Haleakala volcano road" tour?


Teletubbies?


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## aclinjury (Sep 12, 2011)

gregkcubed said:


> as a heavy guy, commuting in all weather on a bike with anywhere from 10-20 pounds of extra stuff on it, I can't wait to get disc brakes.
> 
> My current bike is a "touring" bike but the brakes suck so much, with any extra weight on it, it is dangerous to slow down. No it's not the pads, its not the wheels, it's just they don't stop very quickly with all that weight. If its wet outside, forget about it.
> 
> ...



I'd say that's a pretty good summary, but I'd like to add 2 more

6. Guys who like to ride carbon rims, especially in the mountains (when pros when they're not racing would use aluminum)
7. Heavy guys who like to use lightweight race bikes (along with lightweight components) when these bikes are built with skinny guys in mind.

It's all cool. I see rim and disc coexisting. I don't see rim brakes and aluminum wheels going away. However, I do see carbon wheels in the future will be manufactured strictly for use with disc brake.


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## LVbob (Mar 24, 2014)

aclinjury said:


> 7. Heavy guys who like to use lightweight race bikes (along with lightweight components) when these bikes are built with skinny guys in mind.


At 6'1 and 175 pounds am I a heavy guy or just in no man's land?


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## aclinjury (Sep 12, 2011)

LVbob said:


> At 175 am I a heavy guy or just in no man's land?


hmm, hmm. Ok I'd say you're more clyde.

skinny = 130 - 150 lbs max!
i'm 120 lbs. Maybe that's why I don't care for disc eh. Maybe that's why I have a hard time understanding the plight of the big guys eh. Honestly I dare not use 2 fingers on the rear brake lever (even descending at over 40 mph) for fear of accidentally locking it (and yes I have unintentionally locked the rear on 2 occasion using 2 fingers).


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## aclinjury (Sep 12, 2011)

Neb said:


> I run a wide rim + wide tire, with lower pressure. Makes crappy roads much more tolerable.
> 
> To take it to the max, I have a 41c tire lined up for my cx bike for gravel riding. I think that counts as a wide tire, right?


Tell you a scarry moment. While back I was messin around with a friend's cx bike. Was doing a short descent, forgetting that i was on a cx bike with squishy tires, fat tires, but squishy nonetheless. Took a corner that I usually take at a speed that I usually take, and holy sh*t! almost wiped out as the front tire's sidewall partially folded and rolled on me. Scarry when you can actually hear the tire scream and squeal against the pavement. Stood the bike up and managed to scrub some speed off, and came about a foot from banging into the metal guard rail (which would have been total devastation). Miracle that I didn't crash.


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## poff (Jul 21, 2007)

C60 disc, as soon as it will become available, I will have my hands on it.


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## ziscwg (Apr 19, 2010)

BikeLayne said:


> I think it was finally decided that some people want disc brakes and others do not.


This is road cycling. You don't get a choice. There are rules.


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## LVbob (Mar 24, 2014)

aclinjury said:


> hmm, hmm. Ok I'd say you're more clyde.


Geez, a 32" waist and I'm a clyde. I guess I chose the wrong sport - back to running, knees be damned.


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## gregkcubed (Apr 14, 2009)

aclinjury said:


> hmm, hmm. Ok I'd say you're more clyde.
> 
> skinny = 130 - 150 lbs max!
> i'm 120 lbs. Maybe that's why I don't care for disc eh. Maybe that's why I have a hard time understanding the plight of the big guys eh. Honestly I dare not use 2 fingers on the rear brake lever (even descending at over 40 mph) for fear of accidentally locking it (and yes I have unintentionally locked the rear on 2 occasion using 2 fingers).


I tried on my current bike many times to lock a wheel - either one. Can't do it if it's dry.

I'm not even close to the maximum slowing rate on my current ride. Whenever i'm on a bike w/ disc brakes, I'm like 'holy ****, i can stop!'

I'm like 230.. sometimes w/ a trailer + 40-50 or panniers +20...

the bike is a fuji touring c2007?


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## ziscwg (Apr 19, 2010)

tom_h said:


> ... overweight Hawaii tourists on a "coast down Haleakala volcano road" tour?





MMsRepBike said:


> what the hell? are those like crash suits? ahahaha.


Crash suits and single speed cruisers. Now, my info is dated on why this set up is required.

Apparently, tour companies were setting up these tours down the volcano. The top 1/4 is a national park from what I remember. A few unskilled tourists decided they wanted more speed than they had skills for. So, they went off some roads and cliffs.

The park service said that anyone on a bike tour had to be controlled and in a space crash suit, or something similar.

I do know there is a race the top every yr sponsored by a local bike club. 10000 ft and 35 miles of climbing. Yeah, that's a good recovery day. Disc brakes would be freakin awesome for that decent, if you are still alive that is.


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## mambo (Jul 29, 2012)

tlg said:


> You've reached a new level of low. You weren't attacking peoples compacts in the other thread. You were directly attacking their riding abilities. What you specifically said was people who didn't ride 53/39 were not "_real cyclists_".
> Give it up, it's REALLY getting pathetic.


I want a 53 sized disc brake!


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## MoPho (Jan 17, 2011)

LVbob said:


> Geez, a 32" waist and I'm a clyde. I guess I chose the wrong sport - back to running, knees be damned.


Well aclinjury failed to mention he is only 4 feet tall 







.


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## Alex_Simmons/RST (Jan 12, 2008)

Whacked said:


> And any issue with wind resistance or aerodynamic drag caused by disk rotors and cables... my sides hurt bad from laughing so hard.
> Anything you may feel is all in your head. You will not notice any difference. In a wind tunnel hooked up to machines you can measure it. Practicality the difference is insignificant.


I'm glad you are amused, but whether a difference is significant or not depends on what's important to each individual, so don't make that judgement for others. 

One year I placed one step higher on the podium in national championships ITT by just 1/100th of a second. So for me such things _do_ matter.

Ironically, someone recently tested some minor changes to bike and set up, and this is the level of aero difference and feel-able impact they found:
AngryAsian: Aero differences you can feel - BikeRadar


Disk brakes add net air resistance over a good rim brake set up, there's no avoiding that. 

Whether that level of added air resistance matters to you or anyone else, or is a reasonable cost for the other benefits (real or perceived) provided, is, well, individual. For some such equipment may well be a great idea, for others much less so.

But don't completely discount aero impacts. They exist whether or not you believe it, or indeed whether or not you think you can feel them. What matters is whether that level of impact matters to the individual concerned. Recreational riders, commuters for instance may not care, but those racing or chasing performance quite possibly do.


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## arai_speed (Aug 19, 2003)

MoPho said:


> Well aclinjury failed to mention he is only 4 feet tall
> 
> .


could this be a picture of aclinjury?


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## Whacked (Feb 14, 2011)

I quit reading once I got to the mention of using a wind tunnel. 
Controlled environment. 
Is that big open space outside your front door a controlled environment? 
Didn't think so.
So if you want to believe it's the equipment that placed you on the podium rather than your own fitness and skill...


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## Alex_Simmons/RST (Jan 12, 2008)

Whacked said:


> I quit reading once I got to the mention of using a wind tunnel.
> Controlled environment.
> Is that big open space outside your front door a controlled environment?
> Didn't think so.


Physics of fluid dynamics doesn't magically change just because you're in a tunnel. But in any case, I've done years of field based (i.e. out in the "real world") aerodynamics testing. Guess what? Yep, tunnel data (well good tunnel data) is valid. 

But that's already been demonstrated and documented in research papers years before I started doing it/ It's not really in dispute.



Whacked said:


> So if you want to believe it's the equipment that placed you on the podium rather than your own fitness and skill...


Your argument is a false dichotomy. It's all those things combined. 

When performance is the primary objective, why ignore something responsible for 90% of the resistance force we face when riding at race speeds on flat roads?


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## Trek_5200 (Apr 21, 2013)

Of course disc brakes will catch on. There's a segment of the bike market that is very much into the newest gadgets, be it disc brakes, power meters, electronic shifting , what have you, etc. Some of these make sense, some don't and some have their uses in certain settings. Disc brakes certainly aren't required, and for many road conditions not warranted, but it will be more than a niche, if not the standard. One thing is clear, the price of a bike excluding the frame is becoming more and more expensive.

Anyone take a look at the five year chart on Shimano?


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## docfuel (Feb 9, 2004)

*I love heavy*



Waspinator said:


> I can see their benefit for offroading, but for road?


Who needs a road bike if you're not racing crits or perhaps stage races.
I have 5 bikes--2 with discs 3 without.
I wish my 15# road bike was an 18# 'cross bike--with discs.
I LOVE my 30+# Fargo and my MTB.
I'll never want discs for my Tri/TT bike--not aero.
My old beater is what it is.


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## aclinjury (Sep 12, 2011)

MoPho said:


> Well aclinjury failed to mention he is only 4 feet tall
> 
> .


of course I could be a smurf! But i'm 5'7", ha!


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## Camilo (Jun 23, 2007)

BikeLayne said:


> I think it was finally decided that some people want disc brakes and others do not.


I'll have to read back through the thread, but I'm pretty sure it was also decided that either the pro-disc or the con- disc people were less than thoughtful and/or pedantic?


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## gregkcubed (Apr 14, 2009)

Alex_Simmons/RST said:


> Physics of fluid dynamics doesn't magically change just because you're in a tunnel. But in any case, I've done years of field based (i.e. out in the "real world") aerodynamics testing. Guess what? Yep, tunnel data (well good tunnel data) is valid.
> 
> But that's already been demonstrated and documented in research papers years before I started doing it/ It's not really in dispute.
> 
> ...


It sort of feels like you guys are talking about different sports. If you're an avid racer, then everything matters. If you're doing this for fun or fitness or commuting, then weight and aero doesn't really make much difference - and a lot of people end up with a lot more bike than they need. WRT brakes, for my usage, higher stopping power is vastly more useful than speed or acceleration. 

I'm primarily tour/commuting right now. For me, if I want to lose weight on my bike, I should just stop eating desert and shed a few pounds.


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## Trek_5200 (Apr 21, 2013)

gregkcubed said:


> It sort of feels like you guys are talking about different sports. If you're an avid racer, then everything matters. If you're doing this for fun or fitness or commuting, then weight and aero doesn't really make much difference - and a lot of people end up with a lot more bike than they need. WRT brakes, for my usage, higher stopping power is vastly more useful than speed or acceleration.
> 
> I'm primarily tour/commuting right now. For me, if I want to lose weight on my bike, I should just stop eating desert and shed a few pounds.


Unless I'm riding a descent I'm not likely to exceed 20 mph 21 mph tops and will probably average in the mid to high teens. At those speeds, I don't see aero playing a huge role for me. I suppose I could ride the drops and achieve far more gains that way.


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## SwiftSolo (Jun 7, 2008)

Your desire to treat gearing like an on-off switch is humorous. Racers and old ladies have at couple of things in common. Some are more fit for climbing than others. Both can find climbs that are so steep and long that they simply can't make the summit in their 39/25.

Consider that the notion that, if we were all racers instead of Freds, we'd all be riding a max of 39/25 (regardless of gradient) may have it's foundation in mental rather than physical fitness.


Trek_5200 said:


> Actually, I think it's great that this option is available. It opens up cycling and terrain to people who wouldn't be able to enjoy it otherwise. I just believe everyone should be honest about it. I'm surprised at how sensitive people are about this.


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## aclinjury (Sep 12, 2011)

LVbob said:


> Geez, a 32" waist and I'm a clyde. I guess I chose the wrong sport - back to running, knees be damned.


man.. if you're doing hardcore running, those guys are even more obsessed with weight and part of the obsession has to do with limiting the damage to the knee. A 175 lb guy like yourself can actually race in a top level cycling race, even in the Tour or a big classic, and have a real chance of winning. But a 175-lb runner? Forget it brother! I think cycling is much much more forgiving than running because a big guy can actually use his powerful legs to leverage the mechanical advantage of a bicycle, and at the same time not abuse his knees too much. In running, the more power you produce, the more pounding your knees will need to absorb, and human anatomy for the big runners is such that they can generate more power (and force) with their big muscles but yet their knee can only handle the pounding as much as a skinner guy. Ligaments and more importantly meniscus for big guys don't grow proportionately with muscles. So in term of force per unit area, bigs guys take punishment much more than smaller guys. You probably know this already. When I was running, 115-117 lb was the norm. And the fast guys who were in the 6' tall range would be about 140-150 lbs. In term of weight/height, top runners are even skinnier than top cyclists. I actually think that I'm too skinny for cycling, and that if I gain more weight, I would be stronger overall. But I too have bad knee (due to motor accident) and I've been told by my ortho that it's best for me to stay as light as possible for the rest of my life.


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## aclinjury (Sep 12, 2011)

gregkcubed said:


> I tried on my current bike many times to lock a wheel - either one. Can't do it if it's dry.
> 
> I'm not even close to the maximum slowing rate on my current ride. Whenever i'm on a bike w/ disc brakes, I'm like 'holy ****, i can stop!'
> 
> ...


Just curious what brakes are you using? I find the Shimano 6700/7900 and the newer 6800/9000 series to be top notched, better than Sram and Campy in terms of stopping power and modulation (especially the 6800/9000 series). The older caliper stuff, ehh, they're less powerful, less modulation feedback though.

Shimano 6700/7900 or 6800/9000 plus aluminum rims will be good for any rider up to 190-200 lbs. Beyond this, I'd go hydro disc.

But 230 you're on the heavier side of things, plus the panniers, well now we're talking truck heavy. In your case, disc makes perfect sense. And there are already touring bikes with disc. And my contention against disc is not on a touring bike, but on a proper racing bike. But this has been discussed on RBR ad nausea

But in the rush to embrace disc, I see some folks in here think that disc will be their savior on a mountain descent. I'm not talking about commuter, wet rainny rider, or randoneur rider. I'm talking about folks who are timid descenders, folks who lack the skills to go fast downhill, are looking to disc as their solution to go fast. Eh.. false sense of security. These little 140mm rotors are too skimpy IMO. If you get disc, it needs to start in 160 - 180 mm range, and go to 200 mm for a person of your size IMO.

Hell on my old steel bike from the early 90s with the old Dura Ace 7400 group, I'm still using the old orginal ceramic Mavic rims, with the same original Shimano brake pads, and that bike has well over 10,000 miles on it. But I did recently replaced the pads, yeah they were worn down to half the thickness, but also they were starting to crack due to the rubber hardening and oxidizing. As for the Mavic rims, still using them, no sign of them wearing down to the point I'd consider ditching them. But again, I'm a lightweight. Guess that is why I have a difficult time understanding the plight of the big guys!


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## GOTA (Aug 27, 2012)

Bill2 said:


> I think they will eventually dominate the market, just like on cars. In the wet they are like night and day.


That's been my experience. I bought a bike with BB7 discs and they've been great in all weather. Near my house is a very long and steep hill that ends with a stop sign and a 3 way intersection. Usually I take a route going up it because the stop at the bottom of the hill is so dramatic. The disc brakes have been a huge improvement on that hill over the 105 rim brakes on my other bike.

Most of the time the braking is pretty close but in particular situations like the one above I'm happy to have the discs.


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## DrSmile (Jul 22, 2006)

aclinjury said:


> Tell you a scarry moment.


It's only scarry if you crash!


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## walrus (Jan 29, 2004)

Disks brakes? I'd be grateful for cantilever brakes. 1/2 my rides are up Mt. Tamalpias and the ride down is about 30 minutes constantly on the brakes. My hands are sore from braking for so long. Once when I got to the bottom my hands were so tired I couldn't shift for a few seconds. I have Utegra 6700s and aluminum rims.


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## MMsRepBike (Apr 1, 2014)

walrus said:


> Disks brakes? I'd be grateful for cantilever brakes. 1/2 my rides are up Mt. Tamalpias and the ride down is about 30 minutes constantly on the brakes. My hands are sore from braking for so long. Once when I got to the bottom my hands were so tired I couldn't shift for a few seconds. I have Utegra 6700s and aluminum rims.


 6700 are pretty hard on the hands indeed. 6800 are actually a lot easier on the hands but it still sucks going down long switchbacked mountains.


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## Alex_Simmons/RST (Jan 12, 2008)

gregkcubed said:


> It sort of feels like you guys are talking about different sports. If you're an avid racer, then everything matters. If you're doing this for fun or fitness or commuting, then weight and aero doesn't really make much difference - and a lot of people end up with a lot more bike than they need. WRT brakes, for my usage, higher stopping power is vastly more useful than speed or acceleration.
> 
> I'm primarily tour/commuting right now. For me, if I want to lose weight on my bike, I should just stop eating desert and shed a few pounds.


Yes indeed we are, which is why I'm neither for or against such equipment, merely pointing out the issues one should or could consider when choosing what's appropriate for them will depend upon their individual circumstances. 

For some a disk brake makes little sense for several reasons, for others it would be a very good thing for hem to have.

My point has never been to suggest they are not a useful addition to a bike, rather that adding one comes at a performance cost if maximising speed from the power you have is a high priority for you. If it's not, and other considerations are of higher priority, then what's a good choice changes.


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## Alex_Simmons/RST (Jan 12, 2008)

Trek_5200 said:


> Unless I'm riding a descent I'm not likely to exceed 20 mph 21 mph tops and will probably average in the mid to high teens. At those speeds, I don't see aero playing a huge role for me. I suppose I could ride the drops and achieve far more gains that way.


Now I don't want to assume what's important to you personally, as that's a function of the type of riding you do amongst other things, but just wanted to point out that air resistance exists at all non-zero speeds and is not trivial even at modest cycling speeds.

Indeed on flat roads air resistance presents the largest resistance force for speeds over about 10mph / 16km/h. At those speeds it represents ~ 50% of the total resistance force. The power demand at those speeds is still fairly modest though, and as speed increases the power demand goes up very quickly.

By the time you are doing 25km/h (15.5mph) air resistance accounts for more than 70% of the resistance forces you face when cycling on flat ground.









Aerodynamics is still the major factor determining speed from the power you have available, even at quite modest speeds.

Like I say, people who trundle along may not be all that concerned with performance and not concerned with their speed. 

But from a physics POV, it's incorrect to say that at lower speeds aero doesn't play a huge role. 

What changes at lower speeds is the relative importance people place on performance.


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## Fredrico (Jun 15, 2002)

walrus said:


> Disks brakes? I'd be grateful for cantilever brakes. 1/2 my rides are up Mt. Tamalpias and the ride down is about 30 minutes constantly on the brakes. My hands are sore from braking for so long. Once when I got to the bottom my hands were so tired I couldn't shift for a few seconds. I have Utegra 6700s and aluminum rims.


Just sayin'--I read this from a pro: when descending, best not to ride the brakes. :nono: That heats up the rims, risking tire blowout, or with tubulars, as I had descending Mt. Wilson, melting the glue and rolling a tire off the rim in a high speed corner! :shocked: 

The writer recommended braking hard, that is to say, "positively" before corners, then letting the descent accelerate on the straight. Let it go. Brake only when you have to, before the next corner. This gives the rims some time to cool off. The rolling resistance of the tires, the grade, the headwind, prevented descending faster than 45 mph off Mt. Wilson, so it was easy to slow down enough to handle the corners confidently. 

I thought then and still feel the main reason for death grip on the brakes is FEAR of going fast.  Wiping out at 45 mph would not be pretty.


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## DrSmile (Jul 22, 2006)

Fredrico said:


> Just sayin'--I read this from a pro: when descending, best not to ride the brakes. :nono: That heats up the rims, risking tire blowout, or with tubulars, as I had descending Mt. Wilson, melting the glue and rolling a tire off the rim in a high speed corner! :shocked:
> 
> The writer recommended braking hard, that is to say, "positively" before corners, then letting the descent accelerate on the straight. Let it go. Brake only when you have to, before the next corner. This gives the rims some time to cool off. The rolling resistance of the tires, the grade, the headwind, prevented descending faster than 45 mph off Mt. Wilson, so it was easy to slow down enough to handle the corners confidently.
> 
> I thought then and still feel the main reason for death grip on the brakes is FEAR of going fast.  Wiping out at 45 mph would not be pretty.


This is the accepted wisdom for all types of brakes. Even with cars you shouldn't drag the brakes going down long hills. The idea is to allow the brakes to cool on the straights so they function well in (or more correctly before) the corners. 

Not sure how it works with Formula 1 though where brake temperature is very important for the compounds they use. If the brakes cool too much in Formula 1 you have NO brakes!


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## BikeLayne (Apr 4, 2014)

.....


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## Fredrico (Jun 15, 2002)

DrSmile said:


> This is the accepted wisdom for all types of brakes. Even with cars you shouldn't drag the brakes going down long hills. The idea is to allow the brakes to cool on the straights so they function well in (or more correctly before) the corners.
> 
> Not sure how it works with Formula 1 though where brake temperature is very important for the compounds they use. If the brakes cool too much in Formula 1 you have NO brakes!


I've read or heard that at the speeds they go, all it takes is a couple of taps on the pedal to heat up the components. Not sure how accurate that is.

Initially when streaking down the mountain, I freaked at the possibility of losing all at 45 mph, but when I took my hands off the brake levers, lo, my speed increased only a few miles per hour and then stabilized against the wall of air. "Gee, this ain't so bad!" I marveled at the motorcycle-like stability of the bike at speeds never attained for more than a half mile! Wary of hitting something, nonetheless, I could relax and work with the bike. It behaved even more predictably at 45 mph than it does at 17 mph! Bellissimo, Ugo, bellissimo! :thumbsup:


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## walrus (Jan 29, 2004)

Fredrico said:


> Just sayin'--I read this from a pro: when descending, best not to ride the brakes. :nono: That heats up the rims, risking tire blowout, or with tubulars, as I had descending Mt. Wilson, melting the glue and rolling a tire off the rim in a high speed corner! :shocked:
> 
> The writer recommended braking hard, that is to say, "positively" before corners, then letting the descent accelerate on the straight. Let it go. Brake only when you have to, before the next corner. This gives the rims some time to cool off. The rolling resistance of the tires, the grade, the headwind, prevented descending faster than 45 mph off Mt. Wilson, so it was easy to slow down enough to handle the corners confidently.
> 
> I thought then and still feel the main reason for death grip on the brakes is FEAR of going fast.  Wiping out at 45 mph would not be pretty.



I try to use the brakes as little as possible, but the road has a lot of switchbacks and rough surfaces where I really need to brake hard and slow way down. I'm not on the brakes all the time, but stronger brakes would make my ride a lot easier.


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## FastWayne (May 20, 2014)

I really needed disc brakes today! I got brake fade on the downhill. It didn't feel good.
There were stop lights near the bottom. top speed was only 37 mph bt I had to start braking way before the intersection. I currently have K swiss black compound, rear show wear I'll order new set. crappy rim brakes, they will have to do until I can afford a new frame.


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## CliffordK (Jun 6, 2014)

A few days ago, a car turned right in front of me (although it had been in front of me as I was accelerating through a left hand turn at a stop light). Anyway, I had to slam on the brakes. Locked one or both wheels on dry pavement.

I'm using 30 or 40 yr old universal side-pull brakes, nothing fancy.

I suppose sometimes I feel I'm not stopping quick enough, but one can generally do fine with well adjusted rim brakes. Wet brakes?

A few years ago when I was commuting over a hill, I wore out a set of Rigida rims with the pads going through the side of the rims.

The big question is what the hit from weight will be. I did see a fairly lightweight set of disc brakes, but many road bikers would be reluctant to accept an extra half pound, or pound of weight for the brakes, hubs, and mounts.

Anyway, you could probably make a list of advantages/disadvantages. 

Rim brakes, cheap, old technology, compatible with most bikes on the road. Maximum sized braking surface. 
Weight? 
Stopping power... probably not a big difference when dry, but perhaps a slight advantage of the disc brakes when the rims/wheels are wet. 
Less damage to the rim (carbon, or heavy commuting). 

I would imagine that over the next few years we'll see more and more disc brakes on road bikes. However, I doubt we'll ever see 100% market penetration. Perhaps a bit more with carbon rims, if the weight of the brakes can be kept down (titanium rotors?)


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## gregkcubed (Apr 14, 2009)

I think the pro-disc people would say that they would have better modulation on the brakes to avoid locking both wheels. (locking both wheels doesn't equal max stopping efficiency, although it's probably close).

The rest of this debate has been pretty well covered above.

Salient points:
1. Weight of the rider/any gear onboard. I weigh 230. Put me on a bike that stops great for a guy who weighs 130 and the brakes are being tested in a different way.

2. Weight on the bike. I personally literally don't give a **** about how much my bike weighs. I really don't. I don't race. I have a huge belly and I put 20 pounds of gear on it anyway.

3. Bad conditions. Some people live in San Diego and the weather doesn't matter. Some people ride in the winter with ice and snow. Having done that a lot, I can tell you that canti brakes with my weight going down a hill are truly terrifying. They just straight out suck for that application.

The max braking surface argument is sort of irrelevant with newer disc brakes.


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