# Carbon rim durability



## JDCowboy (Jun 7, 2004)

OK, I made a mistake. I bought some inexpensive Chinese carbon rims. They actually work great and I like them--until they fail. Front one has warped/delaminated on two different rims coming down steep hills on a hot day. Time for a new bike and I like somewhat aero carbon wheels, but now I'm wondering if I need disc brakes instead of rim brakes. 

I am looking at Giant, Trek, Specialized and Cannondale bikes with carbon wheels and both rim and disc brake options. Rim brakes are, of course, lighter and cheaper. 

Should I give up on the rim brakes and go with discs for security? I am not looking for feedback on whether road bikes should have disc brakes, just on whether I can trust OEM carbon wheels with rim brakes from major manufacturers to hold up.


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## crit_boy (Aug 6, 2013)

I would trust OEM wheels from any of those more than cheap chinese carbon wheels. 

Discs are a valid consideration for a road bike. I would go disc and carbon wheel over rim brake and carbon wheel. 

But, I would just buy metal wheels. See blog and posts from November. 

My perspective: I work for a living, race occasionally, ride group rides 2 or 3 days/wk, ride too much (about 6,000 miles so far this year), have a mtb and a cx bike with hydraulic discs, and a road bike with rims brakes. My current stable is all carbon frames. Other than their cool aesthetics, I have little desire to ride carbon wheels. Mainly b/c I don't think the cost justifies the benefit for me and I don't want to have to change brake pads or buy a second set of carbon wheels as an extra set.


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## JDCowboy (Jun 7, 2004)

I appreciate your comments, crit_boy, but all the higher end road bikes have carbon wheels. Question of whether I should risk rim brakes or pay more for discs.


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## Srode (Aug 19, 2012)

What specific bike models of those brands are you calling higher end that you are interested in? 

The only way I would consider disc brakes on a road bike is hydraulic - I have these on my gravel bike and they are VERY nice, but on a pure road bike I see no reason for them and wouldn't pay more for something that just adds weight to the bike. I've had mechanical disc brakes and they just didn't perform as good as rim brakes with the exception of in wet conditions where they were better. Mechanical disc brakes require more effort and are more prone to making noise. If you don't plan to use the bike in adverse weather I would recommend not paying more for disc brakes and certainly not if they are not hydraulic.


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## Peter P. (Dec 30, 2006)

Yes, disc brakes are THE solution for carbon rims. I'm not a fan of carbon wheels so I'll stick with aluminum rims, but if carbon wheels are what you want, switch to disc brakes and solve all the problems inherent in carbon wheels.

Except about no-name Chinese carbon rims. You're asking for trouble with anything that's sold out the back door at very attractive prices.


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## Jay Strongbow (May 8, 2010)

Give the choice between about $160 for rims that work vs $4000 or whatever for a new bike with disk brakes (which offset the point of aero rims) choosing the latter sounds kind of dumb to me.

I suppose if you can sell your current bike that would offset the blow.

If you feel you need disk brakes for the riding you do to stay safe that's a different story. I've never felt I do for anything I'd consider 'road cycling'. But just for the sake of using carbon rims would seem kind of foolish.

But it's your money and if the look of your rims is that important go for it.


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## ergott (Feb 26, 2006)

JDCowboy said:


> I appreciate your comments, crit_boy, but all the higher end road bikes have carbon wheels. Question of whether I should risk rim brakes or pay more for discs.


If your justification for owning carbon wheels is that all high end road bikes have them, I'm sorry but that's a very poor reason. In some terrain, alloy rims are simply a better choice. It's not the end of the world to have alloy wheels.

There's not a single carbon rim manufacturer that can guaranty against all heat related failures. Some companies use better resin for heat control, but nothing is fail proof. 




Sent from my iPad using Tapatalk


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## Notvintage (May 19, 2013)

JDCowboy said:


> I appreciate your comments, crit_boy, but all the higher end road bikes have carbon wheels.


They don't have to. Carbon wheels are 99% fashion, so read what crit_boy said, as he's 100% correct.


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## Cinelli 82220 (Dec 2, 2010)

ergott said:


> all high end road bikes have them


Go to Mallorca in the springtime. Pro Tour teams train there on their carbon superbikes.

Most use alloy rims ie Sky use C35 wheels with alloy brake track. Other teams I saw use regular box section rims. Some cover up or peel off the maker's labels. Alloy nonetheless.


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## JDCowboy (Jun 7, 2004)

Cinelli 82220 said:


> Go to Mallorca in the springtime. Pro Tour teams train there on their carbon superbikes.
> 
> Most use alloy rims ie Sky use C35 wheels with alloy brake track. Other teams I saw use regular box section rims. Some cover up or peel off the maker's labels. Alloy nonetheless.


You must have been watching different version of the Tour de France than I did. EVERY bike had at least 35mm full carbon rims that I saw.


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## JDCowboy (Jun 7, 2004)

Notvintage said:


> They don't have to. Carbon wheels are 99% fashion, so read what crit_boy said, as he's 100% correct.


I am afraid I disagree. I know there's a marketing aspect to carbon wheels just like electronic shifting. Carbon wheels are lighter and more aerodynamic, which is why I want them. I just don't want to worry about them. 

To be fair, I had Trek carbon wheels on my bike for 7 years before I put on the cheaper Chinese wheels. The Trek carbon wheels worked fine and I had no problems bombing down hills with tight turns and hard braking.


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## harryman (Nov 14, 2014)

With rim brakes, I'd go with alloy if I had to choose, with dics, I'd go with carbon if you have the interest and budget. Alloy will usually give you a more comfortable ride FWIW since they are normally more vertically compliant. 

Unless you're buying from Light Bicycles, or comparable, I'd stay away from Chinese rims.


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## Jay Strongbow (May 8, 2010)

JDCowboy said:


> You must have been watching different version of the Tour de France than I did. EVERY bike had at least 35mm full carbon rims that I saw.


I'm pretty sure he wasn't talking about watching videos in Mallorca in the spring thus wasn't talking about watching the TDF at all.


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## Migen21 (Oct 28, 2014)

For the reasons the OP mentioned ( overheating brake tracks) I would not consider a carbon wheel with a rim brake bike.

That leaves two options.

1. Get a disc brake bike and use whatever wheels you want

2. Limit yourself to alloy wheels (as well as less tire clearance, and inferior braking) on rim brakes

After spending the bulk off the last two seasons on good quality hydraulic discs, I find riding my rim brake bike a little unnerving. 

At this point, I personally would not consider another rim brake bike for any purpose, including road only.


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## jpz (Jan 19, 2007)

remember, when pro teams have carbon wheels, they are from the company SPONSOR and free (as are replacements), the riders didn't necessarily chose them,doesn't mean they are good or bad, but in most cases the riders didnt pick the wheels. That said, any 'big' name carbon wheel should be fine.


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## Notvintage (May 19, 2013)

JDCowboy said:


> Carbon wheels are lighter and more aerodynamic, which is why I want them.


How are they more aerodynamic? At what speed and yaw angle? What width? What depth? Lighter? I have a pair of clincher aluminum rims with Tune Mig/Mag hubs in at 1250 grams. What clincher carbon wheels you can buy like that? Also, unless you regularly ride at 30mph at a perfect yaw angle you're wasting your money. But that's cool. We all do on some crap. Lol. I personally believe carbon clinchers with all their inherent flaws were designed by marketing to sell suckers disc brakes.


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## Jay Strongbow (May 8, 2010)

jpz said:


> remember, when pro teams have carbon wheels, they are from the company SPONSOR and free (as are replacements), the riders didn't necessarily chose them,doesn't mean they are good or bad, but in most cases the riders didnt pick the wheels. That said, any 'big' name carbon wheel should be fine.


They also have tubular rims and a team car full of wheels not far behind. Tubulars and clinchers are apples and oranges in this context.

Getting carbon clinchers for the irrelevant aero 'advantage' then using wind catching disc brakes is especially amusing.


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## velodog (Sep 26, 2007)

JDCowboy said:


> You must have been watching different version of the Tour de France than I did. EVERY bike had at least 35mm full carbon rims that I saw.


Read that post again, he didn't say that he was watching any team race, he's talking about what they're using on their *training* rides.


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## Notvintage (May 19, 2013)

jpz said:


> remember, when pro teams have carbon wheels, they are from the company SPONSOR and free. .


Carbon tubulars don't have the overheating issue that clinchers have.


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## JDCowboy (Jun 7, 2004)

Notvintage said:


> Carbon tubulars don't have the overheating issue that clinchers have.


Check out the Tour of Oman. Carbon tubular tires failed in the heat--not the rims!


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## JDCowboy (Jun 7, 2004)

Do any of you commenting actually have carbon rims? Have any of you actually purchatsed a nice bike recently? They come with carbon wheels for everyday riding. If not, then you really do not have any real knowlege of what you're talking about. I want to hear from someone who actually owns and uses carbon wheels.


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## Jay Strongbow (May 8, 2010)

JDCowboy said:


> Do any of you commenting actually have carbon rims? Have any of you actually purchatsed a nice bike recently? They come with carbon wheels for everyday riding. If not, then you really do not have any real knowlege of what you're talking about. I want to hear from someone who actually owns and uses carbon wheels.


Facts are facts. Your logic is about like challenging people saying smoking isn't healthy by asking if they smoke.

Naturally people who know the facts about carbon clinchers and are opposed to using them won't have them (unless they give in for the looks). That would be kind of stupid.

The fact is carbon clinchers don't make a lot of sense for a lot of people and types or riding. If you use them and like them for your riding that's great but it doesn't change the facts people consider in deciding against them.


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## crit_boy (Aug 6, 2013)

JDCowboy said:


> Do any of you commenting actually have carbon rims? Have any of you actually purchatsed a nice bike recently? They come with carbon wheels for everyday riding. If not, then you really do not have any real knowlege of what you're talking about. I want to hear from someone who actually owns and uses carbon wheels.


I have spent more than $15,000 on bikes in the last four years, spent multiple thousands of dollars to race dirty kanza this year, and ride 5 to 6 days per week. I ride faster than a lot of people and a lot of people ride faster than me. 

You got multiple answers to your question. The fact that you didn't get the answer you wanted or the answer that would justify your preference does not mean you did not get an answer. 

If a bike I bought came with carbon wheels would I ride them? Yes. 

Would I ride cheap carbon rims on a disk or rim brake bike? No. 

Do people use carbon wheels with rim brakes as daily drivers? Yes, all the time.

Do carbon wheels look and sound cool? I think so. 

Do some carbon wheels have aero advantages over some alloy rims? Depends on way more factors than I understand. 

Do those people experience rim failures on a daily basis? No, probably not. 

Do alloy rims fail? Sometimes. 

Should you buy a new bike with carbon wheels and rim brakes? It is your money. Buy whatever you want to ride.


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## ergott (Feb 26, 2006)

JDCowboy said:


> Do any of you commenting actually have carbon rims? Have any of you actually purchatsed a nice bike recently? They come with carbon wheels for everyday riding. If not, then you really do not have any real knowlege of what you're talking about. I want to hear from someone who actually owns and uses carbon wheels.


I think I know a thing or two about carbon wheels;-)
































































I still say your reasoning for wanting them are silly. _Because all the pros do, because nice bikes come with them,_ really? You haven't given us any real reason as to why you think they might be advantageous for your riding. Rather, you have personal experience with carbon rims failing albeit, cheap ones that might not have fared as well as others. As I said already, there's no guaranty that even the best carbon rims will stand up to all braking conditions. Look no further than other forums to see cases of even Enve rims failing. It happens.

You also ask about disc brakes so rim failure is not an issue all the while acknowledging that the setup will end up being heavier. Again, why do you want carbon so bad? A high end road bike with quality alloy rims can still be very light and will be ideal in mountainous terrain. What pros do doesn't apply to us. They ride closed roads so never have to drag their brakes. They are usually far more skilled than the average rider so less likely to brake with poor technique. They are also typically a lot lighter than even the likes of most Cat 3 or lesser racers. Finally, they don't use carbon clinchers in the mountains, none of them do.

I have chosen various carbon rims over the years mainly to try them out so I know what I'm recommending. I love them and can afford them. I don't kid myself into saying I need them, never.

I leave it up to others to know if they want them. I surely never tell people to buy carbon wheels because _pros ride them_.


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## November Dave (Dec 7, 2011)

I don't have much to say beyond what Ergott has, but I'm about as versed in carbon wheels as it's possible to be. They were a significant part of our company's revenue for several years. We chose to forego that revenue and deal with the ramifications simply because we think carbon clinchers are ultimately a bad product. 

Pros use tubulars, substantially exclusively. Tubulars are a wholly and completely different wheel system than clinchers. So if a person says that "pros ride Wheel Brand X's model ABC carbon tubulars, and I am riding Wheel Brand X's model ABC carbon clinchers, therefore I am riding nearly the exact same wheels as pros," I would say that no, the inherent differences between tubulars and clinchers so strongly overpower any similarities that the two might share that the wheels are almost nothing alike. 

Put another way, my perspective is that an Ambrosia Nemesis tubular is a closer cousin to a Zipp 303 tubular than a Zipp 303 clincher is to a Zipp 303 tubular.


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## velodog (Sep 26, 2007)

JDCowboy said:


> Do any of you commenting actually have carbon rims? Have any of you actually purchatsed a nice bike recently? They come with carbon wheels for everyday riding. If not, then you really do not have any real knowlege of what you're talking about. I want to hear from someone who actually owns and uses carbon wheels.


What's a nice bike, a high end factory built carbon wonder bike or a custom hand built steel bike from one of the established builders? Or is it a custom Ti framed bicycle, again from one of the established builders?

Do you have any real knowledge of what you are talking about other than what the pros are using?


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## JDCowboy (Jun 7, 2004)

Actually, I do appreciate the comments. The concerns are obviously valid. I'm not trying to emulate the pro's. Far from it. Wouldn't want tubulars, anyway. So I just bought a new Giant TCR and it has carbon wheels, no discs. Thought about waiting for the disc models, but local bike shop gave me 20% off. Decided not to pass that up. My Trek carbon wheels lasted 7 plus years. We'll see how long the Giant wheels last.


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## bikerector (Oct 31, 2012)

Wow, this thread became a crap show quick. OP, chill and listen. You don't have to shoot down every opinion that is different than your own. Of course, facts are facts and that's different. I will say that some guys are being a bit over the top with stating the lack of aero benefits of a carbon rim over aluminum. Data suggests it's more aero at all yaw angles and speeds against a box section rim. It's the cost v benefit that's highly debateable since most aero benefits come from rider position 1st.

Carbon rims fail and have a higher tendency to do so descending than aluminum because they overheat and can delaminate. With clinchers, the tubes can over-inflate from increased heat and blow off rim. With tubulars, the glue can soften. If you followed the tour of Oman well then I'm sure you're aware that the riders like to pump the tires to ridiculously high pressures because the pavement is super smooth and the race is fast and pro riders can be more nostalgic than logical sometimes. Pair the high heat with the excessively high pressure and you get exploding tires. 

A "nice bike" has many different version based on a perspective. A nice bike to one person is something from a bike shop vs Walmart. Another person may only want a carbon bike. In your case, sounds like you only want the best bike available as usually on the most expensive models have carbon wheels. Most manufacturers accept that those buying higher end bikes probably already have nice wheels to go with so you often see wheels lower spec'ed than the rest of the bike, until you get to the top of the line.

Simply because people state "use aluminum" doesn't mean they haven't used carbon. I don't care for carbon clinchers, at all. I've owned 2 pairs and never again. I will only ride carbon in tubulars. I guess that's not quite true as I would try carbon clinchers or tubeless with disc brakes for CX or gravel, but I would likely still stick with a shallow aero aluminum and do tubeless because it's cheaper and generally easier to maintain.

You don't have many posts on the forum so you're probably not aware that many people are "set in their ways" in some regards. Wheels come up all the time as does tire width. Carbon wheels have a place but it's not at the value end of the bike industry, in most scenarios. If you bought Chinese rims, which have a negative stigma here, then we would assume you're not willing to pony up for something nicer, or at least you weren't but now you are.

Another thing to consider if you're going to buy the top of the line bike is that disc brakes seem to be the way the industry is headed. Rim brakes aren't going anywhere but disc brakes are here to stay. I expect there to be some sorting out of hub/axle/thru-axle standards like there was in mtb but it does seem to have settled much better than the mtb world which seems to come out with a new one every other year. I think there are two fork standards for road/cx right now, 12mm and 15mm. Then of course the QR but I think those are on the way out fast for disc brakes.


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## JDCowboy (Jun 7, 2004)

Velodog, Giant TCR Advanced SL 0 is a nice bike (which I bought). Tarmac S-Works is a nice bike. Trek Emonda SLR is a nice bike. Cannondale Supersix Evo's are nice bikes. Those are the major brands available in my local shops and I want to stay local. Yes, I do know what I'm talking about other than what the pro's use. I average over 4,000 miles a year on my road and mountain bikes, race and do a dozen centuries a year. And I have 63 years of mistakes behind me. 

Let's face it, we often buy nicer things than we need. I am fortunate to be able to afford an expensive bike so I want to buy one. Would I be happy on a less expensive bike? Of course! 

I appreciate the comments, even though I may sound like I disagree. I'm an attorney, so I want to understand where comments are coming from. I discount those from people just spouting off and value those from people with actual experience. Crit_Boy, ergott and November Dave made some very good points and I appreciate the feedback.


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## JDCowboy (Jun 7, 2004)

bikerector said:


> Wow, this thread became a crap show quick.


Yeah! Might as well have asked opinions on tubes or tubeless, or go to a motorcycle forum and ask about motor oils! Decided to buy a new bike with carbon clincher wheels. We'll see how they hold up. If they fail, I'll eat my words and buy an aluminum rimmed replacement!


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## crit_boy (Aug 6, 2013)

Nice bike. Congratulations.


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## Srode (Aug 19, 2012)

JDCowboy said:


> Do any of you commenting actually have carbon rims? Have any of you actually purchatsed a nice bike recently? They come with carbon wheels for everyday riding. If not, then you really do not have any real knowlege of what you're talking about. I want to hear from someone who actually owns and uses carbon wheels.


Yes, I have carbon clincher rim brakes and aluminum disc brakes, not carbon wheels with disc brakes though, and my comments on discs are based on my experience. I haven't had nor plan to do any rides with fast technical desents that would require lots of hard braking so the brake track heat isn't a concern for me with carbon and some of the new brake tracks on carbon wheels stop at least as good if not better than aluminum when wet although I do try to avoid wet day rides with them just from a wear and tear standpoint.


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## Jay Strongbow (May 8, 2010)

bikerector said:


> Wow, this thread became a crap show quick. OP, chill and listen. You don't have to shoot down every opinion that is different than your own. Of course, facts are facts and that's different. I will say that some guys are being a bit over the top with stating the lack of aero benefits of a carbon rim over aluminum. Data suggests it's more aero at all yaw angles and speeds against a box section rim. It's the cost v benefit that's highly debateable since most aero benefits come from rider position 1st.


I think everyone knows and acknowledges that deep carbon clinchers are more aero than box alloy rims. The argument is that even in the best of conditions it's not enough to impact anyone's race results (time trials excluded) nevermind offer benefits to just riding around. Especially once you factor in that you can use latex tubes with alloy rims which save watts but can't with carbon clinchers (although you could probably get away with it for many rides) and deep rims can suck in crosswinds.

No doubt carbon clinchers would be fine in certain conditions but I think the assumption with this and most questions is that the question pertains to 'all round' riding which includes rain, hills and wind.


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## No Time Toulouse (Sep 7, 2016)

JDCowboy said:


> Check out the Tour of Oman. Carbon tubular tires failed in the heat--not the rims!


What, now they're selling carbon *tires*???? Wow.....I gotta get that!!!!


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## Srode (Aug 19, 2012)

Jay Strongbow said:


> Especially once you factor in that you can use latex tubes with alloy rims which save watts but can't with carbon clinchers (although you could probably get away with it for many rides)


Huh? Why not? I've probably got 7,000 miles on my carbon wheels with latex tubes without any issues?


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## Jay Strongbow (May 8, 2010)

Srode said:


> Huh? Why not? I've probably got 7,000 miles on my carbon wheels with latex tubes without any issues?


https://enve.zendesk.com/hc/en-us/articles/204228845-Use-of-Latex-Tubes-in-ENVE-Clincher-Wheels

From Challenge:

It is correct to say that latex tubes should not be used in carbon clincher wheels. It is correct to say that latex does not handle heat well compared to butyl.

Butyl rubber can support much higher temperatures for longer periods of time.

The reason why latex works on carbon clincher wheels (this is my personal opinion), is due to the ability of the rider. Expert riders are able to do descents with limited use of brakes and [thus] give the possibility to the equipment to cool down. Never reach extreme heating. The heat is generated on the external part of the rim and will take time to transfer inside the rim. Generally between tire and rim strip, the tube has no direct contact to the carbon rim and if there is no rim strip it is on the cool part of the rim.

Heat in carbon [rims] does not dissipate fast and generally seems to be concentrated in the braking area.

Criterium and other types of riding do not have [the] problem of wheels heating, so latex can be used with no problem. As manufacturers, we do not know how consumers will use the product, and, to be on the safe side, we prefer to give warning not to use it.
— Alex Brauns
President, Challenge Tech


https://www.curvecycling.com.au/pages/tech

From Competitive Cyclist: Despite the removable valve cores, we strongly recommend against using latex tubes with carbon clincher wheels—a sentiment shared by most major wheel, tube, and tire manufacturers. Since the carbon braking surface heats up more than alloy, it can cause latex tubes to burst and fail. If you're running carbon clinchers, go with butyl tubes.


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## hfc (Jan 24, 2003)

True high end bikes for the most part are sold as frame and fork and built out to the buyer's spec, so OP I wouldn't think you're limited to carbon wheels. That being said, I would think durability of a reputable carbon wheel is fine. I have had a set of Zipp 202's and 303's for about 3 years, admittedly fairly low miles as I spread my mileage amongst several bikes. I've been happy with the Zipps and found them to hold up well. Last year on a descent at between 25-30 mph I hit a pothole that blew out both my tubes, the sidewall on the front tire, both tires eaten up during the deceleration, without a mark in the 202's. 

I also rode a Gran Fondo metric Century a few months ago where a friend told me a couple of people somehow screwed up their carbon wheels on a steep winding descent but my 202's held out fine. I am a good descender though and didn't work my brakes too hard😉

I'm not a carbon wheel fan boy but recognize their advantages. I have a couple of bikes with 30 year old Mavic G40 rims that ride great. I am in general, not a fan of disc brakes, unless you do a lot of wet weather riding in the hills or off road riding. Rim brakes are just fine for a skilled rider and IMO not worth the trade off in added weight, aesthetics, and maintenance burden.


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## bikerector (Oct 31, 2012)

Jay Strongbow said:


> I think everyone knows and acknowledges that deep carbon clinchers are more aero than box alloy rims. The argument is that even in the best of conditions it's not enough to impact anyone's race results (time trials excluded) nevermind offer benefits to just riding around. Especially once you factor in that you can use latex tubes with alloy rims which save watts but can't with carbon clinchers (although you could probably get away with it for many rides) and deep rims can suck in crosswinds.
> 
> No doubt carbon clinchers would be fine in certain conditions but I think the assumption with this and most questions is that the question pertains to 'all round' riding which includes rain, hills and wind.


I believe there was an argument that aero wheels in sprints gave a significant enough advantage to be the difference from winning and losing because it would give you those extra few inches when the difference from winning and losing is a bike throw.

I suppose you could factor in that latex tubes could make a difference to even out the difference some. I prefer tubulars for carbon anyway so that argument wouldn't apply to my circumstance but I can see where it could apply.

I also see more tubeless carbon wheels coming out so I wonder if the latex tube part starts to fall flat when/if that becomes more widely adopted. Mavic seems to have an interesting road tubeless system coming out. Not there yet but soon.

Personally, I think I would rather get a rim like a boyd altamont or velocity quill (should be re-released by now) that has some aero benefits (aero profile) than a carbon clincher both for cost and for better all-around use (better braking and wet riding braking). Are the aero benefits better than a box section? Not much probably but they cost about the same so why not.


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## November Dave (Dec 7, 2011)

People seem unaware of the actual differences in aerodynamics between wheels. Tour Magazine most credibly placed a 13w difference between a Mavic Ksyrium and a Zipp 404 (and DT Swiss 65 and one other in this particular test) in the test they published in their issue 8 of 2016 (can't link but it's worth downloading thru their app if you are interested in the actual truth of this versus the promotional hoopla). So that's 13w between what's always been the "dog" of the bunch and the deepest wheels that most people ride for rec or even road racing use. They also tagged a 3w difference between a 303 and a 404, and 303 was more or less equal to Bora 50 and Shimano C50.

Then we coordinated a test in February of this year, the results of which are here. Short answer? A competent ~30mm alloy rim gives ZERO aerodynamics away to a 303. Which by extension means it gives nothing away to a Bora or Shimano 50. And with the difference between latex and normal butyl tubes repeatably coming in at 3w per wheel, you're actually 3w better off with a good set of 30s and latex tubes than 404s and butyl tubes.

303 rims also weigh more than 500g, so the carbons have no weight disadvantage to aero-equivalent carbons, and our anecdotal customer feedback puts stiffness in favor of alloys. 

Put simply, there's really no justification for carbon clinchers unless you are in a very specific high speed time trial case where super deep and very incremental gains are the name of the game. And even there, you're likely better off with a HED Jet+ with aluminum brake track. 

The more you know...


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## alexdi (Jul 1, 2016)

The argument for alloy wheels seems to depend on three propositions:

1. Rim brakes on an alloy brake track are desirable.
2. Carbon's advantages aren't worth the cost 
3. It's latex, butyl, or bust 

I disagree on all counts. 

I've had rim-braked bikes forever. I have three of them now. Rim brakes, on alloy, in the dry, are pretty decent when the wheel is clean. When the wheel isn't clean, or it's the slightest bit out of true, or it's wet or even just humid, they suck. This isn't something you can tune your way out of. I'm a maintenance fanatic and I still think they suck. What you're buying with discs is consistency, and by extension, confidence. Forget hydraulic; I'd take my mechanical TRP Spyres over every rim brake in existence.

I like the mechanical simplicity and the other advantages of a long, symmetrical lever arm for braking, but there's no question the future is in discs, and the trend didn't start because they were fashionable. 

Discs open the door to carbon. For the same wheel profile, carbon can be lighter and stiffer. That's indisputable: I've got a spreadsheet of ~30ish-profile rims in front of me that all undercut the AI33 and XR31T by some margin, they're all Chinese (and therefore under $250 a rim), they'll all hold me off the floor without being laced, and a properly-assembled set won't ever fatigue or need to be trued. And these are the off-brands. ZIP isn't the only premium brand in town; if you really to throw down the bucks, a number of places will build wheelsets 200g lighter than anything comparable (even the word is a stretch if you value stiffness) in alloy. 

The third leg in our future tripod is tubeless. I don't know how many of you guys mountain bike, but all roadies are doing is borrowing the stuff that industry figured out years ago. Less rolling resistance, more comfort, less weight, (way) more resistance to flats: there's a lot to like when you ditch the tubes. By contrast, nobody likes latex. (Why would you? You have to reinflate it every ride.) It doesn't matter to me an iota that I can't use my latex tubes on a carbon rim. 

In sum: while deep-section rims may well have only marginal aero benefits (or not; 13W isn't inconsequential and some data sources show bigger differences), I believe carbon is a superior disc platform, that's where we should be headed, and that's where we are headed.


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## dcb (Jul 21, 2008)

I live in a mountainous area and long, technical descents are all over the place. I was in my buddies bike shop a couple of weeks ago and he had a heat warped carbon fiber clincher wheel that he had sold to a customer that was ready to go back to the manufacturer for warranty replacement. This wheel was from a major brand. I won't mention the name because I've got no interest in slamming their product, and I suspect wheels from other brands wouldn't have fared any better. I can't say anything about how they were actually used because I don't know who they belonged to. 

I also have a buddy I ride with occasionally who is on his 3rd pair of the same carbon clinchers. Again, these are from a major (but different) manufacturer associated with very high end wheels. He climbs a lot - standard after work ride is a 3k+ HC climb that he does 1-2 times a week. This guy keeps on going back to the same wheel because he really likes the ride quality and just accepts that they're going to fail at some point due to heat generated while braking. He's never had an accident and never blown a tire off the rim either when it's happened. I hope his luck holds out. 

The take home message for me is that if you ride where you're going to stress your wheels with long, techy descents, any brand of carbon wheel can fail.


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## alexdi (Jul 1, 2016)

dcb said:


> The take home message for me is that if you ride where you're going to stress your wheels with long, techy descents, any brand of carbon wheel can fail.


At 170 lbs, I took this as a given when I bought a set of rim-braked carbon clinchers. Nobody's using magic resin. The probability of one brand failing over another is a difference of degree, not kind. My area doesn't have many hills or I wouldn't have bothered at all. It amazes me that so many people do.


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## terbennett (Apr 1, 2006)

JDCowboy said:


> I am afraid I disagree. I know there's a marketing aspect to carbon wheels just like electronic shifting. Carbon wheels are lighter and more aerodynamic, which is why I want them. I just don't want to worry about them.
> 
> To be fair, I had Trek carbon wheels on my bike for 7 years before I put on the cheaper Chinese wheels. The Trek carbon wheels worked fine and I had no problems bombing down hills with tight turns and hard braking.



Did the Trek carbon wheels aka Bontrager have aluminum braking surfaces? If not, you just got lucky. However, I recall Bontrager carbon wheels were actually rebadged HED wheels, and HED was dead set on not having carbon braking surfaces. Newwer ones might, but I haven't had a pair in years. As for lightweight, carbon wheels are not always lighter. If you went with a low profile wheel, sub 30 mm, carbon would be a horrible choice outside of climbing and sprints. the reason? Carbon doesn't dissipate heat very well. That's why deep dish carbon or more resilient to it than low profile ones...Since there is less surface space on low profile carbon wheels, they will be more prone to failure from excessive braking. That's what causes carbon to fail. A set of lightweight aluminum wheels can weigh the same and not have the issue at all (American Classic 350 Sprints, for example weigh 1250 grams). You're looking at bikes and assuming that those are the best wheels because the bikes are top tier. The components are expensive, but that doesn't make them better. Maybe they are better for racing, but horrible as an all-around wheel. I race crits and I have two sets of carbon wheels, one is Mavic Cosmic Ultimates and the other is a set of Chinese carbon. I ride and race on the Chinese carbon. No issues whatsoever. Been riding and racing on them since March 2015 and they have been to hell and back. Hubs spin like butter. I use the Ultimates for special rides because I'm not ruining $2800 wheels in a crit crash. If my ride is hilly, common sense dictates you don't use carbon wheels with carbon braking surfaces. They will eventually fail. This problem is why manufacturers have introduced disc brakes. Can't solve the braking issue so they moved the brakes. By the way carbon tubulars don't have the issue. It's an issue exclusive to clinchers.


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## terbennett (Apr 1, 2006)

Jay Strongbow said:


> They also have tubular rims and a team car full of wheels not far behind. Tubulars and clinchers are apples and oranges in this context.
> 
> Getting carbon clinchers for the irrelevant aero 'advantage' then using wind catching disc brakes is especially amusing.


+1. I've been wondering about this for a long time.


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## terbennett (Apr 1, 2006)

ergott said:


> I think I know a thing or two about carbon wheels;-)
> 
> 
> 
> ...


He wants them because he's a newb drinking the marketing Kool Aid. Has no idea what he is getting and is judging based on perception, kinda like I'm doing right now. However, noone with actual knowledge would be asking this question in the first place, so my perception is warranted. You're a wheel builder. If he doesn't believe you, there's no hope for him.


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## terbennett (Apr 1, 2006)

no time toulouse said:


> what, now they're selling carbon *tires*???? Wow.....i gotta get that!!!!


....lol!


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## beeristasty (Jan 1, 1970)

terbennett said:


> This problem is why manufacturers have introduced disc brakes. Can't solve the braking issue so they moved the brakes. By the way carbon tubulars don't have the issue. It's an issue exclusive to clinchers.


What you're saying is that road disc brakes only exist because carbon clincher rims can delaminate after extended braking sessions.

And Campy, Shimano, and SRAM decided to spend all that R&D money to fix a problem that is the responsibility of carbon clincher rim manufacturers... out of the goodness of their own hearts?

I think you may be reaching a bit there.


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## Lombard (May 8, 2014)

terbennett said:


> Did the Trek carbon wheels aka Bontrager have aluminum braking surfaces? If not, you just got lucky. However, I recall Bontrager carbon wheels were actually rebadged HED wheels, and HED was dead set on not having carbon braking surfaces. Newwer ones might, but I haven't had a pair in years. As for lightweight, carbon wheels are not always lighter. If you went with a low profile wheel, sub 30 mm, carbon would be a horrible choice outside of climbing and sprints. the reason? Carbon doesn't dissipate heat very well. That's why deep *section* carbon or more resilient to it than low profile ones...


Fixed. We're talking wheels, not pizza. Just so you know.


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## Lombard (May 8, 2014)

ergott said:


> What pros do doesn't apply to us. They ride closed roads so never have to drag their brakes. They are usually far more skilled than the average rider so less likely to brake with poor technique. They are also typically a lot lighter than even the likes of most Cat 3 or lesser racers. Finally, they don't use carbon clinchers in the mountains, none of them do.


Also, the pros' wheels don't need to last longer than the race they are in. Most have their wheels given to them. The rest of us like our wheels to last longer than one or even a few rides.


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## JDCowboy (Jun 7, 2004)

terbennett said:


> He wants them because he's a newb drinking the marketing Kool Aid. Has no idea what he is getting and is judging based on perception, kinda like I'm doing right now. However, noone with actual knowledge would be asking this question in the first place, so my perception is warranted. You're a wheel builder. If he doesn't believe you, there's no hope for him.


Yes, I'm a newb! After 85 centuries and countless road and mtb races, I'm still trying to figure out what those thingys on the handlebars do! 

Thank you for your experienced wisdom. 

I do appreciate Dave's input as he has the backgound to back up what he says.


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## JDCowboy (Jun 7, 2004)

No Time Toulouse said:


> What, now they're selling carbon *tires*???? Wow.....I gotta get that!!!!


LOL! Ok, the tubular tires failed in the Tour of Oman.


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## JDCowboy (Jun 7, 2004)

The Trek carbon wheels were all carbon and I probably did get lucky. No idea whether they were rebranded or not. 

I've done some searching about some of November Dave's comments. The 30 mm carbon wheels on my new Giant TCR weigh 1334 grams per Giant's website. I have found several sets of aluminum rim wheels that weigh less than 100 grams more, which I will probably use when/if the Giant rims fail out of warranty. I do think there's an aero advantage to deeper wheels but the cost of the carbon rims compared to similar weighing aluminum rims is ridiculous. I've had different wheels on different bikes and I think the hubs make a significant difference as well as the wheel material.


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## Lombard (May 8, 2014)

JDCowboy said:


> I do think there's an aero advantage to deeper wheels.....


Oh definitely! They will make you about 0.1mph faster at sustained speeds of 20mph!



JDCowboy said:


> I've had different wheels on different bikes and I think the hubs make a significant difference as well as the wheel material.


And they may make you an additional 0.05mph faster!

OK, I'm being admittedly snarky. My point is unless you are competing in a race for a large sum of money, it won't matter. 

Lighter rims may make you *feel* faster because they will spin up faster from a stop. Once up to speed, you won't notice a difference.

And hubs? Yes, we are all impressed by hubs that will spin forever in the work stand. But given all the other forces on the bike, you won't notice this either except in extreme cases. Just about all the well known hubs out there are quite good as far as this issue is concerned.

I can tell you for sure that my gravel bike with 500+g rims is just as fast as my road bike with 450g rims. There is a 5lb. difference between the total weight of each bike. The hubs in the road bike spin freer in the stand than those on the gravel bike. I'm not a lightweight, but not a clyde either at 175lbs.


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## JDCowboy (Jun 7, 2004)

I've heard the argument that deeper wheels and better hubs only make you feel faster, and that may be correct. But if they make you feel faster then you feel faster! I have had 50 mm wheels and I felt they allowed me to stay in a paceline and group at speed easier than the shallower wheels I replaced. I have nice hubs on my current bike and I think they make a difference. I am rarely the fastest up the hill but I am never the last down the hill. I also weigh about 175 and I go down hill (in a straight line) faster in the same position than most others. I may be wrong, but I attribute that to the aerodynamics of the bike and the smoothness of the hubs. My observation is that my bike rolls faster than than many other bikes so that if I traded bikes with the guy or gal next to me, they would go faster downhill on my bike than I would on theirs. No way to know unless we actually traded, but that is what it seems like to me. I would also guess that your gravel bike would not keep up with your road bike up or down hills even if they had the same tires. It may be a small difference but I'll bet there is a difference. Thanks for the post.


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## Lombard (May 8, 2014)

JDCowboy said:


> I've heard the argument that deeper wheels and better hubs only make you feel faster, and that may be correct. But if they make you feel faster then you feel faster!


Granted, if that make you enjoy your bike more and want to ride more, then it's all good. 



JDCowboy said:


> I am rarely the fastest up the hill but* I am never the last down the hill*.


Precisely where aero equipment will make a difference. However, your position on the bike (race vs. upright) will make more difference than aero wheels. On uphills, aero won't make any difference.



JDCowboy said:


> I also weigh about 175 and I go down hill (in a straight line) faster in the same position than most others. I may be wrong, but I attribute that to the aerodynamics of the bike.....


Possibly.



JDCowboy said:


> ....and the smoothness of the hubs.


Probably not. What you would notice is if your hub bearings are worn or they are cheap hubs. Any good quality hub - Shimano, White Industries, Chris King, DT, etc. - will probably be equal in rolling resistance.



JDCowboy said:


> I would also guess that your gravel bike would not keep up with your road bike up or down hills even if they had the same tires. It may be a small difference but I'll bet there is a difference.


Possibly a small difference. What was surprising to me is that the difference was not perceivable. At the same time, the gravel bike feels much more stable, planted and compliant giving me more confidence on the much less than perfect roads in my county.


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## JDCowboy (Jun 7, 2004)

Thanks for the comments, Lombard. I just went from an 09 Madone, which was a great bike but I was ready for a change, to a Giant TCR with the integrated seat post. The Giant is both subjectively and objectively faster (my times on the same roads are faster on the Giant). One of the more interesting differences was the downhill stability of the Giant TCR. It is much more stable and goes faster easier on the downhill turns than the Madone, running the same size tires. The Giant actually has slightly more aggressive geometry than the Madone.


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## Lombard (May 8, 2014)

JDCowboy said:


> Thanks for the comments, Lombard. I just went from an 09 Madone, which was a great bike but I was ready for a change, to a Giant TCR with the integrated seat post. The Giant is both subjectively and objectively faster (my times on the same roads are faster on the Giant). One of the more interesting differences was the downhill stability of the Giant TCR. It is much more stable and goes faster easier on the downhill turns than the Madone, running the same size tires. The Giant actually has slightly more aggressive geometry than the Madone.


I had the same experience when I went from a 2007 Trek Pilot OCLV to my 2014 Cannondale Synapse Carbon. The stability is so much better on the Cannondale. The Trek feels like a noodle in comparison. Carbon technology came a long way in 7 years.

The gravel bike I just bought, of course, is way more stable for the obvious reasons of what it is designed for. Wider tires, CroMo steel frame and a slightly longer wheelbase will obviously make a bike more stable. What surprised me is that I initially expected the gravel bike to feel slower. It didn't. It actually feels just as fast if not faster! Placebo effect of a new bike? Hmmmmm, don't think so. Two other riders I let try it out and they said the same thing!


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## changingleaf (Aug 20, 2009)

If you're getting a new bike I highly recommend disc brakes. They solve the problem you are confronted with, plus you have much better and more reliable braking. The biggest negative is that the bike will be a little heavier. The second issue is that if you need to switch wheels you may need to adjust the brakes or true the rotors and that can be a bit of a learning curve.

You should be able to trust oem rim brake rims, but will not get much if any improvement in braking.


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## Notvintage (May 19, 2013)

changingleaf said:


> The biggest negative is that the bike will be a little heavier.


*The biggest negative is that the bike will be heavier, uglier, less aerodynamic and will require more maintenance. Fixed.*


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## coachboyd (Jan 13, 2008)

Notvintage said:


> *The biggest negative is that the bike will be heavier, uglier, less aerodynamic and will require more maintenance. Fixed.*


Actually, the new disc brake bikes are almost right at the same weight as rim brake bikes. You can get them well under 17 pounds.

Aerodynamics is actually starting to get better than rim brake counterparts. Look at the new bikes that completely hide the cables in the frame. Plus there is no bulky caliper brake catching wind.

Ugly is a point of view, but personally something like the new BMC Timemachine with disc brakes, or the new Ridley Noah SL disc looks super attractive to a lot of people.

Maintenance. Just got done riding my gravel bike with disc brakes. Abused it all season long (some good crashes, mud, and sticks), and now I finally have a squealy front brake. It's going to take me 30 seconds to put in new brake shoes, and if I have to replace the rotors it'll take another minute (centerlock FTW).

It's not going to be for everybody, but I think it's a much nicer system (especially with the descending I do).


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## chandne (Jan 22, 2004)

Yup, disc wheels (and centerlock) if buying a new bike, especially if riding near the mountains.


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