# Adapter for 180mm on flat-mount discs?



## Pierre (Jan 29, 2004)

It seems that flat-mounts are made for 140/160 front, 140 rear, that's it. Flip the orientation of the fork adapter for 140 or 160. Now, how can I use 180 in front?? Is there a flat-mount adapter for this?? Apparently there's an adapter for the rear to use a 160 instead of a 140, so I guess it could be mounted on the fork adapter? Two adapters, that sounds super ugly and many screws. Is there a one-adapter solution for 180mm? Thanks -


----------



## nova_rider (Sep 23, 2005)

What type of bike needs a 180mm front rotor?


----------



## fronesis (Jan 22, 2014)

Flat-mount calipers are not meant to be run with 180mm rotors, so anything you cobbled together would be compromise or hack. 

Like Nova, I have to ask: why not just run a 160mm rotor?


----------



## cxwrench (Nov 9, 2004)

As the previous guys posted...what's the thinking behind a 180mm rotor? If you actually 'need' a 180 rotor to slow yourself down what you really need is a different bike. There is no good way to put a 180mm rotor on a bike w/ flat mount calipers.


----------



## Pierre (Jan 29, 2004)

Whether I need a 180mm rotor is irrelevant. I was asking the question out of genuine interest. It is possible to use 180mm with post-mount brakes, so it would make sense to be able to do it as well with flat-mount brakes. What a surprising design, that this is not possible.

By the way, not so long ago, people were saying that disc brakes in general didn't make any sense on road bikes. Other people were saying that wide tires are 'slower' etc...


----------



## cxwrench (Nov 9, 2004)

Pierre said:


> Whether I need a 180mm rotor is irrelevant. I was asking the question out of genuine interest. It is possible to use 180mm with post-mount brakes, so it would make sense to be able to do it as well with flat-mount brakes. What a surprising design, that this is not possible.
> 
> By the way, not so long ago, people were saying that disc brakes in general didn't make any sense on road bikes. Other people were saying that wide tires are 'slower' etc...


Uhmmm no. Flat mounts are pretty much specifically for road bikes. The design and engineering is such that 160mm is the largest rotor that everyone involved is comfortable putting on a road bike. The stopping power generated is good for the majority of riders. If you increase the size of the rotor you increase the leverage created by the brake system on the frame and fork so you'd need to increase the strength of both. To answer your question...again...no, it's not possible to do it safely. I won't make any comments about whether you (think you) need a 180 or not.


----------



## masont (Feb 6, 2010)

Pierre said:


> Whether I need a 180mm rotor is irrelevant. I was asking the question out of genuine interest. It is possible to use 180mm with post-mount brakes, so it would make sense to be able to do it as well with flat-mount brakes. What a surprising design, that this is not possible.
> 
> By the way, not so long ago, people were saying that disc brakes in general didn't make any sense on road bikes. Other people were saying that wide tires are 'slower' etc...


I didn't really care why you wanted to do it until you made a big deal out of not wanting to explain why you wanted to do it, now I'm really curious.


----------



## slope (Aug 9, 2012)

masont said:


> I didn't really care why you wanted to do it until you made a big deal out of not wanting to explain why you wanted to do it, now I'm really curious.


Well, I just picked up a 18 Kona Rove NRB.
I weigh 245 lbs.
Yeah, I'd like to lose some weight which is another reason I got the bike.
160 is nowhere near enough to stop my fat ass.
Lots of people in my situation.


----------



## Steve B. (Jun 26, 2004)

slope said:


> Well, I just picked up a 18 Kona Rove NRB.
> I weigh 245 lbs.
> Yeah, I'd like to lose some weight which is another reason I got the bike.
> 160 is nowhere near enough to stop my fat ass.
> Lots of people in my situation.


160 is plenty. 140 is fine as well. 

Unless you are running really wide tires, like 40mm or larger and carrying a touring load, the issue is going to be tires breaking contact when the brake works great.


----------



## cxwrench (Nov 9, 2004)

slope said:


> Well, I just picked up a 18 Kona Rove NRB.
> I weigh 245 lbs.
> Yeah, I'd like to lose some weight which is another reason I got the bike.
> 160 is nowhere near enough to stop my fat ass.
> Lots of people in my situation.


160 will work. If it doesn't get a different brake set up.


----------



## Finx (Oct 19, 2017)

slope said:


> Well, I just picked up a 18 Kona Rove NRB.
> I weigh 245 lbs.
> Yeah, I'd like to lose some weight which is another reason I got the bike.
> 160 is nowhere near enough to stop my fat ass.
> Lots of people in my situation.


On a bad day I weigh the same as you. 

I ride gravel and road in a hilly region, and I have 10k plus miles on 140/140 and 160/140 and have not had an issue. Even with quick emergency stops. As someone else said, in that situation, you are probably going to lock up a tire, regardless of the size of the rotor.

The one scenario you probably need to be careful of is really long descents where you have to stay on the brakes for an extended period. Just be aware of this, use good technique to keep the brakes cool, and don't get in over your head. You should be fine.


----------



## slope (Aug 9, 2012)

Hmm....I am running cable disc (TRP Spyres).
I am also running wide tires but can't come anywhere near stopping on a dime.
Not even close.
Maybe I'm expecting too much of a "road bike".
Looking at changing pads perhaps.


----------



## aclinjury (Sep 12, 2011)

slope said:


> Hmm....I am running cable disc (TRP Spyres).
> I am also running wide tires but can't come anywhere near stopping on a dime.
> Not even close.
> Maybe I'm expecting too much of a "road bike".
> Looking at changing pads perhaps.


Have you braked hard enough? to the point that the front tire is almost skidding? Practice this hard braking technique in a straight line. If you've clamped on the front brake lever as hard as you could (ie., you're appling all 4 fingers) and you still cannot get the front tire to almost lockup and skid in a straightline, only then would you need to consider going to a more power brake setup.

now to lessen the chances of you folding the front wheel under hard braking, you should perform the above test in a series of increasing speed attempts, this will allow you to feel and hear how the tire is behaving. If you sense that tire is about to lock and skid, just release the front brake and you'll roll out it safely.

but I do think that guys in your weight category is better off with an 180mm rotor though.


----------



## cxwrench (Nov 9, 2004)

slope said:


> Hmm....I am running cable disc (TRP Spyres).
> I am also running wide tires but can't come anywhere near stopping on a dime.
> Not even close.
> Maybe I'm expecting too much of a "road bike".
> Looking at changing pads perhaps.


I'll bet a dollar your brake isn't set up correctly. You can go from very powerful to won't do a damn thing in less than 10mm of cable if you don't adjust them correctly.


----------



## masont (Feb 6, 2010)

slope said:


> Hmm....I am running cable disc (TRP Spyres).
> I am also running wide tires but can't come anywhere near stopping on a dime.
> Not even close.
> Maybe I'm expecting too much of a "road bike".
> Looking at changing pads perhaps.


Your problem isn't rotor size. Plenty of big guys do just fine on 160. 

Either you need new pads and a rotor cleaning, your bike is brand new, or your brake just isn't set up properly at all. Any one of those will cause you to not have the power and modulation you should, and that's totally independent of rotor size.


----------



## Okcorrell (Jan 1, 2021)

I created an account to specifically support your efforts with a search for a 180mm flat mount fork adapter. These other responses are pretty elitist at best (if you don’t have something or constructive to say, keep your keyboard to yourself). I am also on the search for a 180MM front rotor for increased modulation and additional heat dissipation for long, aggressive descents. I haven’t found anything out there for SRAM, but Shimano seems to have one. Good luck with your search!






Pierre said:


> Whether I need a 180mm rotor is irrelevant. I was asking the question out of genuine interest. It is possible to use 180mm with post-mount brakes, so it would make sense to be able to do it as well with flat-mount brakes. What a surprising design, that this is not possible.
> 
> By the way, not so long ago, people were saying that disc brakes in general didn't make any sense on road bikes. Other people were saying that wide tires are 'slower' etc...


----------



## ogre (Dec 16, 2005)

Okcorrell said:


> I am also on the search for a 180MM front rotor for increased modulation and additional heat dissipation for long, aggressive descents.


Increasing the rotor size will not increase modulation, and may actually decrease it. Also, difference in surface area between a 140mm rotor and a 160mm rotor is negligible (do the math), so that won't affect heat dissipation. And the OP started this thread over two years ago so I bet he or she has moved on from this topic. 

But hey, welcome and thanks for joining! This place is a ghost town. Yeah, some posters can be acerbic but there's a lot of knowledge you can get from this site.


----------



## Okcorrell (Jan 1, 2021)

ogre said:


> Increasing the rotor size will not increase modulation, and may actually decrease it. Also, difference in surface area between a 140mm rotor and a 160mm rotor is negligible (do the math), so that won't affect heat dissipation. And the OP started this thread over two years ago so I bet he or she has moved on from this topic.
> 
> But hey, welcome and thanks for joining! This place is a ghost town. Yeah, some posters can be acerbic but there's a lot of knowledge you can get from this site.


I got a noticeable increase in modulation and power when I went from 180 to 200 on my downhill mtn bike. All good. Thanks for nice reply and feedback. I am always looking to learn and figure out new ways to send it! Happy/safe riding out there!


----------



## ogre (Dec 16, 2005)

Okcorrell said:


> I got a noticeable increase in modulation and power when I went from 180 to 200 on my downhill mtn bike.


Sure, you'll get more 'power' by increasing the diameter of the rotor. To be extreme, imagine applying an equal force to stop a tiny 100mm rotor versus a giant rotor closer to the outside diameter of the rim. Which one will stop you better with the same amount of force applied? Car manufacturers have long took advantage of this - the bigger the rim diameter, the larger the rotor they can use. And it's possible to over-engineer the bike. You don't want 230mm rotors on a road bike.


----------



## Okcorrell (Jan 1, 2021)

ogre said:


> Sure, you'll get more 'power' by increasing the diameter of the rotor. To be extreme, imagine applying an equal force to stop a tiny 100mm rotor versus a giant rotor closer to the outside diameter of the rim. Which one will stop you better with the same amount of force applied? Car manufacturers have long took advantage of this - the bigger the rim diameter, the larger the rotor they can use. And it's possible to over-engineer the bike. You don't want 230mm rotors on a road bike.


Perhaps this was the wrong forum for the question as my application is a gravel bike that use largely road bike parts. I routinely hit 15-22% grades and long steep descents in Northern California. Any help with confident, reliable braking is welcome.


----------



## Lombard (May 8, 2014)

Okcorrell said:


> I created an account to specifically support your efforts with a search for a 180mm flat mount fork adapter. These other responses are pretty elitist at best (if you don’t have something or constructive to say, keep your keyboard to yourself).


Welcome to RBR where anonymity breeds hostility!  Seriously, some posters can be harsh and like to throw their weight around, but can be helpful anyway.



Okcorrell said:


> Perhaps this was the wrong forum for the question as my application is a gravel bike that use largely road bike parts. I routinely hit 15-22% grades and long steep descents in Northern California. Any help with confident, reliable braking is welcome.


Well I guess if you are descending 20%+ long hills, you need all the braking help you can get. Are you climbing those same 20%+ hills? Heck, anything more than around 16-17% and I'm walking!


----------



## Okcorrell (Jan 1, 2021)

Thanks for welcome! Yes, decency is often lost in a faceless world. 


Lombard said:


> Welcome to RBR where anonymity breeds hostility!  Seriously, some posters can be harsh and like to throw their weight around, but can be helpful anyway.
> 
> 
> 
> ...


Yes, but I am not breaking any records in any respect. Grind, grind, grind my way to the top. The descents are made even trickier with loose gravel on the majority of double track fire roads. Happy and safe riding!


----------



## nova_rider (Sep 23, 2005)

I'd argue that pros can and will descent steeper, faster, and brake harder than anyone here, yet I am not aware of any complaints about 160mm not being sufficient from any of the top-tier pro teams.

Effective braking has more to do with knowing the proper technique than having fancy hardware.


----------



## Lombard (May 8, 2014)

nova_rider said:


> I'd argue that pros can and will descent steeper, faster, and brake harder than anyone here, yet I am not aware of any complaints about 160mm not being sufficient from any of the top-tier pro teams.
> 
> Effective braking has more to do with knowing the proper technique than having fancy hardware.


I'm also guessing if the OP is doing mostly gravel and off-road riding, he's not bombing down the hills super fast in the first place.


----------



## ogre (Dec 16, 2005)

Lombard said:


> I'm also guessing if the OP is doing mostly gravel and off-road riding, he's not bombing down the hills super fast in the first place.


Bombing down the hills is a lot easier on the brakes than creeping down.


----------



## Lombard (May 8, 2014)

ogre said:


> Bombing down the hills is a lot easier on the brakes than creeping down.


Bombing down and then trying to slow down after getting up to 40+ mph or more?


----------



## nova_rider (Sep 23, 2005)

Lombard said:


> I'm also guessing if the OP is doing mostly gravel and off-road riding, he's not bombing down the hills super fast in the first place.


Ok, so I will ask what is the problem again?


----------



## Lombard (May 8, 2014)

nova_rider said:


> Ok, so I will ask what is the problem again?


My point was in confirming your point in case it wasn't obvious.


----------



## Okcorrell (Jan 1, 2021)

nova_rider said:


> I'd argue that pros can and will descent steeper, faster, and brake harder than anyone here, yet I am not aware of any complaints about 160mm not being sufficient from any of the top-tier pro teams.
> 
> Effective braking has more to do with knowing the proper technique than having fancy hardware.


I agree with you. Despite the elite advice, I am not a pro rider. I also would not consider 180MM fancy hardware.


----------



## duriel (Oct 10, 2013)

Are u using cable or hydraulic brakes? Due to the long descents that I do, I changed to hydraulic, and it is a world of difference drag braking.


----------



## Chantecler (Jan 18, 2021)

ogre said:


> Increasing the rotor size will not increase modulation, and may actually decrease it. Also, difference in surface area between a 140mm rotor and a 160mm rotor is negligible (do the math), so that won't affect heat dissipation. And the OP started this thread over two years ago so I bet he or she has moved on from this topic.
> 
> But hey, welcome and thanks for joining! This place is a ghost town. Yeah, some posters can be acerbic but there's a lot of knowledge you can get from this site.


Pi R squared would be entire volume of a disk, move r from 70 to 80 and r squared goes from 490 to 640 times Pi (3.142) and the difference (150 delta x 3 is massive). Or just diameter, 2Pi x r = about every millimetre increase in radius is over 6 times increase in diameter... so a 140-160 disk increases diameter from c6x70 to c6x80 = 420mm diameter to 640mm diameter. So the diameter increase is over 50% From 140 to 160. I mean just in my head, no calculator or anything.


----------



## Chantecler (Jan 18, 2021)

Btw I have a canyon lux (xc) that runs flat mount 180 front and 160 rear. Nothing unusual with those sizes even for weight weenie world champions, who would shift down if they could but don’t want to lose heat dissipation, modulation etc.


----------



## cxwrench (Nov 9, 2004)

Chantecler said:


> Pi R squared would be entire volume of a disk, move r from 70 to 80 and r squared goes from 490 to 640 times Pi (3.142) and the difference (150 delta x 3 is massive). Or just diameter, 2Pi x r = about every millimetre increase in radius is over 6 times increase in diameter... so a 140-160 disk increases diameter from c6x70 to c6x80 = 420mm diameter to 640mm diameter. So the diameter increase is over 50% From 140 to 160. I mean just in my head, no calculator or anything.


You've forgotten your maths. 
Every mm increase in radius = 2mm increase in diameter. Circumference is the word you were looking for. A 140 or 160mm disc is just that...140mm or 160mm diameter. Trying to sound smart only works when you get everything right.


----------



## Lombard (May 8, 2014)

cxwrench said:


> You've forgotten your maths.
> Every mm increase in radius = 2mm increase in diameter. Circumference is the word you were looking for. A 140 or 160mm disc is just that...140mm or 160mm diameter. Trying to sound smart only works when you get everything right.


I'm no smartypants, but it's surface area that is significant here. Doing the calculation Pi * R * R:

For a 140mm disc, 3.142 * 70 * 70 = 15,396 sq mm

For a 160mm disc, 3.142 * 80 * 80 = 20,109 sq mm

Difference = 4,714 sq mm

So, the 160mm disc has 30.6% more surface area than the 140mm.

Of course I am reminded of a quote from one of my favorite posters on this forum, DCGriz, who wisely said, "With bicycles in particular, it is important to separate what is merely true and what is important". A bike with 140mm disc brakes still has more stopping power than a similar rim brake bike. Unless you plan on riding your brakes down 1-mile long steep hills or longer, the 140mm disc brakes will slow and stop you just fine without melting.


----------



## duriel (Oct 10, 2013)

If your going to do an exact calculation, are those are the outside diameters? The actual center line of the caliper may a significantly different than those numbers.


----------



## Lombard (May 8, 2014)

duriel said:


> If your going to do an exact calculation, are those are the outside diameters? The actual center line of the caliper may a significantly different than those numbers.


Oooops! You are correct! The usable surface is not Pi * R * R because of the spider. So you would need to know the radius of the inner disc surface As I said, I'm no smartypants!


----------



## duriel (Oct 10, 2013)

I think one could flip the bike with rim/120/140/160/180 brakes, so in reality, we are discussing modulation & heat dissipation. The bigger the brakes the better the modulation & heat dissipation, no calculation is required.
My new moto has sexy twin front brakes, don't ask me why.


----------



## ogre (Dec 16, 2005)

Lombard said:


> I'm no smartypants, but it's surface area that is significant here. Doing the calculation Pi * R * R:
> 
> For a 140mm disc, 3.142 * 70 * 70 = 15,396 sq mm
> 
> ...


I'm no smarty pants either but you're forgetting something. Say the rotor surface is 10 mm 'wide'. So the surface area is a 160mm rotor is (3.14 * 80 * 80 = 20,096 sq mm) LESS the surface area of a 150mm circumference circle (3.12 * 75 * 75 = 17,663 sq mm), so total surface area is 20,096 - 17,663 = 2,434

Same calculation for a 140 mm rotor - (3.14 * 70 * 70 = 15,386 sq mm) LESS (3.14 * 65 * 65 = 13,267 sq mm), total surface area is 15,386 - 13,267 = 2,120

So the 160mm rotor has about 15% more surface area.


----------



## duriel (Oct 10, 2013)

I don't know why you guys are worried about the surface area of the disk that the pad hits. If the rotor is connected to a plate that is the full internal diameter, that calc isn't right either. My disks have a metal heat dissipater that goes from the disk all the way into the hub, and it's vented!

The only braking is done by the pad! Which is virtually the same size on most brakes. The only thing that changes is the distance from the axle.


----------



## Lombard (May 8, 2014)

duriel said:


> I don't know why you guys are worried about the surface area of the disk that the pad hits. If the rotor is connected to a plate that is the full internal diameter, that calc isn't right either. My disks have a metal heat dissipater that goes from the disk all the way into the hub, and it's vented!
> 
> The only braking is done by the pad! Which is virtually the same size on most brakes. The only thing that changes is the distance from the axle.


You are correct. DOH! So it appears the only advantage to larger discs is greater heat dissipation - unless you also have larger pads.

Didn't I say I was no smartypants?



ogre said:


> I'm no smarty pants either but you're forgetting something. Say the rotor surface is 10 mm 'wide'. So the surface area is a 160mm rotor is (3.14 * 80 * 80 = 20,096 sq mm) LESS the surface area of a 150mm circumference circle (3.12 * 75 * 75 = 17,663 sq mm), so total surface area is 20,096 - 17,663 = 2,434
> 
> Same calculation for a 140 mm rotor - (3.14 * 70 * 70 = 15,386 sq mm) LESS (3.14 * 65 * 65 = 13,267 sq mm), total surface area is 15,386 - 13,267 = 2,120
> 
> So the 160mm rotor has about 15% more surface area.


As I corrected myself in Post #36


----------



## Lombard (May 8, 2014)

D


----------



## nova_rider (Sep 23, 2005)

duriel said:


> I don't know why you guys are worried about the surface area of the disk that the pad hits. If the rotor is connected to a plate that is the full internal diameter, that calc isn't right either. My disks have a metal heat dissipater that goes from the disk all the way into the hub, and it's vented!
> 
> The only braking is done by the pad! Which is virtually the same size on most brakes. The only thing that changes is the distance from the axle.


The larger diameter will have greater surface areas on both the rotor and cooling fins to dissipate heat, thus less fade. The slight caliper mechanical advantage can translate to less effort/better modulation.


----------



## Lombard (May 8, 2014)

nova_rider said:


> The larger diameter will have greater surface areas on both the rotor and cooling fins *to dissipate heat, thus less fade*. The slight caliper mechanical advantage can translate to less effort/better modulation.


Of course you will only notice the "less fade" part if you are in a situation where fluid may boil.


----------



## nova_rider (Sep 23, 2005)

Lombard said:


> Of course you will only notice the "less fade" part if you are in a situation where fluid may boil.


If your fluid boils, it's not fade, but rather brake failure. Fade occurs when the rotor and/or pad overheats and lose friction during heavy application. Fluid boil is often caused by prolong dragging of pads on the rotor with light application, or a big no-no when it comes to proper braking techniques.


----------



## duriel (Oct 10, 2013)

It is a difficult issue.
Going fast DH, overall is easier on the brakes, until they are called into duty. Then they are under a lot of stress, pressure & temperature sky rockets, oil may boil at that point but is suppressed due to thermal mass.
Going slow DH, overall is harder on the brakes. Drag braking will slowly build temperatures where the oil will boil constantly, there is no suppression due to thermal mass.

He never did answer my question on cable vs hydraulic. I think he just wants to argue.


----------



## cxwrench (Nov 9, 2004)

Lombard said:


> I'm no smartypants, but it's surface area that is significant here. Doing the calculation Pi * R * R:
> 
> For a 140mm disc, 3.142 * 70 * 70 = 15,396 sq mm
> 
> ...


I promise you the area of the entire circle isn't 15 or 20 square meters... and we're only talking about the swept area.


----------



## Finx (Oct 19, 2017)

Such an RBR thing to do to resurrect a sleeping thread to argue the details of the math involved with a question that has already been answered.

Back to the original question, I'm not aware of a way to adapt a flat mount road disc to 180mm rotor. it might be possible, but you would be looking at some fringe hack, and not something the brake manufacturer or frame designer would likely endorse.

I'll re-iterate, speaking from a lot of experience as a heavy rider on a heavy'ish bike on steep, sketchy terrian (I live in the Cascade Mtn foothills, where fire roads are not only steep and sketchy in terms of surface, but also quite muddy due to rain), that 160mm should be adequate. If not, you might look at upgrading to a better quality brake caliper. Good quality hydraulic disc brakes with 160mm rotors stop my fat ass - they should stop yours as well...


----------



## Lombard (May 8, 2014)

cxwrench said:


> I promise you the area of the entire circle isn't 15 or 20 square meters... and we're only talking about the swept area.


Umm, your conversion from sq mm to sq m is off by a few decimal points. 15,000 or 20,000 sq millimeters = 0.015 or 0.02 sq meters. That IS the area of the entire circle.

And I thought YOU were a smartypants.


----------



## cxwrench (Nov 9, 2004)

Umm, your conversion from sq mm to sq m is off by a few decimal points. 15,000 or 20,000 sq millimeters = 0.015 or 0.02 sq meters. That IS the area of the entire circle.

And I thought YOU were a smartypants. 
[/QUOTE]
1000mm =1meter. How am I off?


----------



## Lombard (May 8, 2014)

cxwrench said:


> 1000mm =1meter. How am I off?


1000mm = 1meter, correct.

1000 sq mm does not equal 1 sq meter.

Hint: 12 sq inches does not equal 1 sq foot.

Hint: How many sq feet is 1 sq yard? How many cubic feet is 1 cubic yard?


----------



## cxwrench (Nov 9, 2004)

D'oooohhhh.


----------



## duriel (Oct 10, 2013)

This is not a thread druggie, a guy joined to get the same question answered, then he didn't like anyone's answer, so he when back to his fake world.


----------



## Chantecler (Jan 18, 2021)

cxwrench said:


> You've forgotten your maths.
> Every mm increase in radius = 2mm increase in diameter. Circumference is the word you were looking for. A 140 or 160mm disc is just that...140mm or 160mm diameter. Trying to sound smart only works when you get everything right.


Lol, I agree, I used diameter instead of circumference, but I obviously knew my maths as I used radius (being half diameter) and calculated circumference increase (which is what affects area: add 1mm to circumference and you get over 6mm squared volume extra... the non linear nature is what you missed, actual impact on area depends on depth of area heated by brake, and then actual heating depends on materials used etc). But well done, you keep on focussing on diameter and ignore the exponential difference in surface area. 140 to 160.... no big deal you say (ie what is an extra 20 on 140?). Bad maths if you are talking about either surface area (cooling) or braking impact, where again distance from hub is not linear in effect.


----------



## overl0ad (Feb 16, 2021)

just to add fuel the the fire...

i've been toying with this idea of going 180mm in the fronts and 160mm in the rears with 4 pots both ends

OR

180mm front and rear with 4 pots in the front and 2 pots in the rear.

not that i need it, and i freely admit that i don't.

want to do it "just cos i can",

only thing i'm wondering about is that fluid displacement from the levers.

any comments about the fluid displacement?

edit: yes, i know i'll ned to go PM calipers to do 4 pot.ideally, i'd like to stick with my 2 pot FM calipers for now and just go 180/160


----------



## spiroX (Nov 13, 2019)

Sorry to resurrect an old thread, but I have the same issue.
I have a Kona Rove NRB DL with ultegra 8020 levers and calipers. Front brake was never particularly good. Whenever I was on a MTB, even with altus or similar, brakes were much better. I could never lock my front wheel, but on MTBs I could see that happening. I don't own a MTB and am fairly new (2years) to cycling so I have never tried another road bike. Prior to this Kona I had another Kona Rove with spyre C mechanical disc brakes and those were worse.
I have since switched to metallic pads and ultegra rotors as previous rotors were not designed for metallic pads. That improved the situation a bit. My ultegra brakes have now failed, just after 1 year of usage. 1 of the pistons has jammed and only one works. LBS had no luck in unjamming it so I got new calipers. Because of covid I could only find 105 which are (I think) the same brakes, and they feel the same.
So now I am thinking either there is something wrong with my levers, although 2 bike mechanics didn't notice anything unusual, and brakes have been bled by a good mechanic, or the brakes/levers are just not as good as MTB ones? One strange thing is that my rear ones work too good!?! So much so that it is really easy to lock my rear wheel. I have to be extra careful when braking with rear wheel. I was even thinking going to 140mm at rear because of this! But I'm just being careful not to overdo it, and I am using resin pads at the rear which seem to give better modulation.
I see all this videos telling you how to brake not to go over the bars, but I am never even close to this. When in the drops I can apply full throw of the lever, so that the lever is right next to the bar and I will stop, but I don't feel as confident as on a MTB. The lever is not hitting the bar or something like that, it can't go any further. In the hoods on a steep descent I do not think I would stop, at least not soon enough, I am ALWAYS on the drops when riding descents just for this reason.

Now my options are:
1. Go to SRAM. This would mean that I have to change shifters AND calipers. Very expensive, but I did read on a few places that SRAM feel "better". I don't know is it true or if it brakes better.
2. Get Hope RX4+ calipers. Supposedly those brake better, certainly a lot cheaper than full SRAM groupset
3. Get MTB calipers, like SLX ones. They have flat mount SLX, but would have to check if it is compatible with ultegra levers, and I don't know if it would improve the situation.
4. Get 180mm rotors, and (make?) adapters for 180mm flat mount.

For the last point, a few observations:
a) Going from 160 to 180 rotors, and assuming brake surface center is 10mm less then rotor radius, it would increase braking power by appx. 15% because of the bigger lever. Assuming same force is applied to brake levers.
b) There would be more modulation, again, due to bigger lever.
c) More heat dissipation, but I don't have an issue with heat. I use finned pads and ultegra rotors have an aluminium center made for cooling so they dissipate the heat very well.
d) There are adapters for post mount so there is no technical reason not to make one for flat mounts. As long as the angle and position of the pads on the rotors is the same it will work without any issues. As I need only 1 adapter, and have access to aluminium and tools, I could probably make it myself.
e) Larger rotors will apply more torque to the fork, but ONLY when applying full lever throw, and that would be 15% then. With a good robust gravel fork this should not be an issue.

I should also mention that I am not Chevy, 80kg (appx 160bs), and have extra few kilos on the bike when touring. Bike is appx 10kg.

Any opinions on SRAM, Hope or MTB calipers? Or 180mm with adapters?

Sorry for the GIANT post, but there is not much info for 180mm rotors on road bikes, and with gravel it is surprising to me this still isn't a thing.


----------



## duriel (Oct 10, 2013)

I think the OP was cable brakes, LP is hydraulic. Everyone on this post wants to go to big rotors. IMO, if you can keep your small rotors if you get your brakes adj and brought back up to original condition.
Bleed your levers, clean the rotors, clean the calipers and replace the pads. If the pads then become contaminated, get new calipers and start all over with the whole system.

Standard rotors should be able to throw you over the bars, if they can't there is one of those above items that is defective.


----------



## spiroX (Nov 13, 2019)

I was afraid someone will say that. I have 2 sets of rotors with plenty of meat on them, cleaned, and now even new 105 calipers. Still poor braking. So maybe there is something wrong with brake levers themselves. Those are not cheap.
I'll try to find someone with road hydro brakes to try them out. If they perform better then mine it must be the levers.


----------



## overl0ad (Feb 16, 2021)

do you have any contamination from silicon? 

from my last post, i took a really close look at the forks with the wheel n disc in and i'm 100% the 180's will fit in there.

metallic pads did make a big difference, but only after a few hundred km's did the disc / pads bed in proper. finding a good hill and coming down at 60kmh helped.


----------



## spiroX (Nov 13, 2019)

overl0ad said:


> do you have any contamination from silicon?


Where exactly do you mean? On the rotors? They were cleaned with alcohol, and brake pads are new.


> from my last post, i took a really close look at the forks with the wheel n disc in and i'm 100% the 180's will fit in there.


I think most bikes that can handle wider gravel tires should be able to fit 180mm rotors. It is only 1cm more in radius.
BTW 25.4mm=1inch. There are adapters for 140 to 160mm rotors. It's still strange for me that no one offers 160 to 180 flat mount adapters, or gravel brakes with either 4 pistons or for 180mm rotors.


> metallic pads did make a big difference, but only after a few hundred km's did the disc / pads bed in proper. finding a good hill and coming down at 60kmh helped.


I used to have metallic at the front, now it's resin only because my local shop didn't have it at the time. I'll go back to metallic. I also live in a very hilly area and do 100-200km a week so they bed in rather quickly 

I see that you were wondering about fluid displacement from the levers. As long as the calipers are ment for those levers that shouldn't be an issue. I don't think Shimano 4 piston MTB calipers are ment (compatible) for their STI shifters, but Hope makes them specifically for Shimano or SRAM road shifters.


----------



## overl0ad (Feb 16, 2021)

contamination as in some silicon from some spray. i used "mr sheen" on my bike, but i'm careful when i use it.

in terms of displacement, while the MTB stuff does now have FM, i don't know if the pistons are machined the same internally for fluid displacement. chances are that they look the same, but who know without measuring them


----------



## spiroX (Nov 13, 2019)

overl0ad said:


> contamination as in some silicon from some spray. i used "mr sheen" on my bike, but i'm careful when i use it.


I didn't use any silicone spray on my bike. I wash it with just soap, degreaser on the chain and casette is applied using a toothbrush, and I lubricate the chain with a dropper. But the rotors are cleaned anyway.


> in terms of displacement, while the MTB stuff does now have FM, i don't know if the pistons are machined the same internally for fluid displacement. chances are that they look the same, but who know without measuring them


I see your point, I suppose it's true, but most companies to be competitive today use as many interchangeable parts as possible. It saves on research and manufacturing costs. Fun fact: Volvo (just one example) offers 4-5 diesel engines today with main engine being the same. They add parts to make it more powerful like turbo or supercharger. Sometimes the change is just in the engine control unit. You can just reprogram it and get the more powerful engine.
Also Shimano does offer flat mount for MTB in SLX, XT and XTR range.
And they (including road ones) REAAAALY look the same 
I imagine (I could be wrong) that they are all the same except for highest range XTR and dura-ace being of lighter material, but still dimension wise, the same.


----------



## duriel (Oct 10, 2013)

I'm installing a turbo on mine right now.


----------



## Killvin (Jul 28, 2021)

Pierre said:


> It seems that flat-mounts are made for 140/160 front, 140 rear, that's it. Flip the orientation of the fork adapter for 140 or 160. Now, how can I use 180 in front?? Is there a flat-mount adapter for this?? Apparently there's an adapter for the rear to use a 160 instead of a 140, so I guess it could be mounted on the fork adapter? Two adapters, that sounds super ugly and many screws. Is there a one-adapter solution for 180mm? Thanks -


whisky makes a fork that can adapt for 180 rotors using a normal flat mount 160 adaptor. I just installed one on a customers bike and if you are willing to get a new fork you can do it.


----------



## overl0ad (Feb 16, 2021)

so, seems that Hope do a 4 pot flat mount which can run a 180mm rotor

they have 2 options/variations to accommodate DOT fluid or mineral oil



StackPath


----------



## jedifrogmstr (12 mo ago)

nova_rider said:


> What type of bike needs a 180mm front rotor?


One that needs to stop!!


----------



## nova_rider (Sep 23, 2005)

jedifrogmstr said:


> One that needs to stop!!


Nonsense. I know of no major bike brands that offer 180mm front rotor on their road models, so I guess none of these can stop.

When it comes to hauling down a bike, the limiting factor is often the tire contact patch, NOT the rotor size.


----------



## overl0ad (Feb 16, 2021)

so, as a joke, i went from 160 to 140

the initial bite and modulation isn't as good

already running metal pads on a DA 9200 setup. so... there is some logic to the need to go bigger rotor for those who prefer a more positive initial feel and modulation.


----------



## duriel (Oct 10, 2013)

One should probably wear a parachute if running 180 rotors, in case the front locks up and doesn't skid.


----------



## Lombard (May 8, 2014)

duriel said:


> One should probably wear a parachute if running 180 rotors, in case the front locks up and doesn't skid.


How would you get the front tire to skid if it locks up. It won't happen, you're going on a flying lesson.


----------



## PBL450 (Apr 12, 2014)

Lombard said:


> How would you get the front tire to skid if it locks up. It won't happen, you're going on a flying lesson.


No! It’s discs. You don’t lock up the front and go over the bars because discs are so much better. 


Sent from my iPad using Tapatalk


----------



## Lombard (May 8, 2014)

PBL450 said:


> No! It’s discs. You don’t lock up the front and go over the bars because discs are so much better.


How can I forget? Disc brakes are the solution to everything including warts and hemorrhoids.


----------



## duriel (Oct 10, 2013)

I do have a new wart, but my disk brakes don't seem to affect it too much. I thought it was a rock under the skin and digging it out didn't help either. 
Disk brakes are better PERIOD!


----------



## overl0ad (Feb 16, 2021)

guys, this isn't productive. 

we are here to discuss the options to go 180 on the front discs for a roadie.


----------



## PBL450 (Apr 12, 2014)

overl0ad said:


> guys, this isn't productive.
> 
> we are here to discuss the options to go 180 on the front discs for a roadie.


My fairy dragon makes less fire when it’s 180! That’s the level of discussion we are at here. 


Sent from my iPad using Tapatalk


----------



## MtManChad (12 mo ago)

Pierre said:


> It seems that flat-mounts are made for 140/160 front, 140 rear, that's it. Flip the orientation of the fork adapter for 140 or 160. Now, how can I use 180 in front?? Is there a flat-mount adapter for this?? Apparently there's an adapter for the rear to use a 160 instead of a 140, so I guess it could be mounted on the fork adapter? Two adapters, that sounds super ugly and many screws. Is there a one-adapter solution for 180mm? Thanks -


Here’s the answer To your adapter question. I’m a bigger rider and living in the mountains need more stopping power than a 160 in front offers.

















Discord 180mm Flat Mount Disc Brake Fork Adapter


Made for steel or super beef carbon forks, so you can get 23% more stopping power with a 180mm rotor vs a 160mm rotor. Two piece design. You'll see why that has to the be case when you get it. Comes with stainless hardware. US made and anodized. Silver or Black. Not sure if your fork can handle...




analogcycles.com


----------



## duriel (Oct 10, 2013)

If you put those on, you're going to have to sit 23% lower cause when you hit the brakes your going over the bars, end of story. You're iether going to fly down 4' or over the guard rail for a big dive.


----------



## Lombard (May 8, 2014)

duriel said:


> If you put those on, you're going to have to sit 23% lower cause when you hit the brakes your going over the bars, end of story. You're iether going to fly down 4' or over the guard rail for a big dive.


It all in learning how to use your brakes and applying gradual pressure. It isn't hard.


----------



## MtManChad (12 mo ago)

cxwrench said:


> As the previous guys posted...what's the thinking behind a 180mm rotor? If you actually 'need' a 180 rotor to slow yourself down what you really need is a different bike. There is no good way to put a 180mm rotor on a bike w/ flat mount calipers.


there actually is a good way to mount a 180mm see my last post. “Engineering minds always come up with solutions”


----------



## MtManChad (12 mo ago)

Lombard said:


> It all in learning how to use your brakes and applying gradual pressure. It isn't hard.


So when I went from a 160 to 200 on my mountain bike I didn’t go over the bars and way more power with way less finger effort or long ride fatigue. I don’t buy 160mm rotors for 200+ riders on very long mountain Descents They just don’t cut it and get way too hot. I’m a mechanical engineer and it’s simple math more leverage more power even if you don’t need it all it’s better than working something underside way too hard for the job at hand.


----------



## Lombard (May 8, 2014)

MtManChad said:


> So when I went from a 160 to 200 on my mountain bike I didn’t go over the bars and way more power with way less finger effort or long ride fatigue. I don’t buy 160mm rotors for 200+ riders on very long mountain Descents They just don’t cut it and get way too hot. I’m a mechanical engineer and it’s simple math more leverage more power even if you don’t need it all it’s better than working something underside way too hard for the job at hand.


Well if you are prepared for the fact yoy will have more braking power, you won't go over the bars. If you apply the same pressure you did before, then there is a good chance you will do an endo. It's all about being prepared for change.


----------



## MtManChad (12 mo ago)

Lombard said:


> Well if you are prepared for the fact yoy will have more braking power, you won't go over the bars. If you apply the same pressure you did before, then there is a good chance you will do an endo. It's all about being prepared for change.


I’m just posting this to reply to the original question so people know somebody makes one 
I’ve been riding for 28 years and never flipped a bike because too much front break. I’ve seen progression from crappy rim brakes as a kid to mechanical then hydraulic disk when people thought they were a dumb idea but they work great in snow and rain and can get real hot and still work.


----------



## overl0ad (Feb 16, 2021)

thanks heaps for the linkage.

i'm sure that there will be lots of people who are quietly appreciative for it.


----------



## duriel (Oct 10, 2013)

So you are going to believe some guy who rides a road bike with disk brakes on the ski slopes????? Ha!


----------



## overl0ad (Feb 16, 2021)

duriel said:


> So you are going to believe some guy who rides a road bike with disk brakes on the ski slopes????? Ha!


sorry, was this for me?


----------



## duriel (Oct 10, 2013)

It's for anyone who will read it! ~~
I now do agree that bigger brakes on a mtn bike is better, but on the road why are you on the brakes?










`


----------



## MtManChad (12 mo ago)

duriel said:


> So you are going to believe some guy who rides a road bike with disk brakes on the ski slopes????? Ha!


it’s along a gravel road, go find a new thread and bash on somebody else or go for a ride! 
I’m just getting info to people seeking parts.


----------



## Lombard (May 8, 2014)

MtManChad said:


> it’s along a gravel road, go find a new thread and bash on somebody else or go for a ride!
> I’m just getting info to people seeking parts.


He can't ride, he hurt his booger finger and now he can't even pick his nose.


----------



## overl0ad (Feb 16, 2021)

duriel said:


> It's for anyone who will read it! ~~
> I now do agree that bigger brakes on a mtn bike is better, but on the road why are you on the brakes?


i don't know about everyone else, but i personally quite like being able to come to a stop quickly with better modulation on the road bike.

even more so when i'm coming down a hill at >50KMH and a car pulls out in front of me or the lights goes red. also found that it's helpful when there are hairpins and other such things.

i know you don't need brakes when you're riding on the velodrome, so i'm guessing that you've removed all your brakes to save some weight and get more aero?


----------



## Lombard (May 8, 2014)

overl0ad said:


> i don't know about everyone else, but i personally quite like being able to come to a stop quickly with better modulation on the road bike.


Good modulation is important and lessens the chance of locking a wheel. Hydraulic disc brakes do this well. But modern rim brakes also do this quite well - maybe not quite as well as hydraulic disc brakes, but in the grand scheme of things and for road riding, good enough. I don't know if mechanical disc brakes have become any better, but I rode a mountain bike with mechanical disc brakes about a decade ago and the modulation sucked - they were grabby.


----------



## duriel (Oct 10, 2013)

I've rode them all, rim, mech disk, hydraulic disk, road & mtn. I have lifted the rear wheel off the ground stopping with my road hydraulic disks with standard size disks. 
I think I'll try going mano, remove them all and just use my foot or finger (haven't decided yet) between the frame & tire, we'll see how that goes.


----------



## Lombard (May 8, 2014)

duriel said:


> I've rode them all, rim, mech disk, hydraulic disk, road & mtn. * I have lifted the rear wheel off the ground stopping with my road hydraulic disks with standard size disks. *


You can do this with any type of brakes if you don't know how to use your brakes. It's all about learning how to use your brakes correctly.


----------



## duriel (Oct 10, 2013)

I did it on purpose, I wanted either to stop as fast as possible or to spin turn, it wasn't a mistake.


----------



## nova_rider (Sep 23, 2005)

If bigger is better, I'll just stick with my 622mm rotor.


----------



## Lombard (May 8, 2014)

nova_rider said:


> If bigger is better, I'll just stick with my 622mm rotor.


<Drumroll>


----------



## overl0ad (Feb 16, 2021)

i think the factor that rim brakes don't come up tops is when it's wet.

used to run the open pro ceramics, and truth is those still don't stop as well as hydros.

i appreciate that 160 is enough for most people, and 180 is over the top for most.

but let's also be honest. 105 on an alloy frame will also be sufficient for majority of people.


----------



## 103 (Oct 20, 2009)

nova_rider said:


> What type of bike needs a 180mm front rotor?


A race winning bike does. 


https://www.cyclingnews.com/news/a-dropper-post-wasnt-mohorics-only-tech-hack-for-milan-san-remo/?utm_medium=social&utm_campaign=socialflow&utm_content=cyclingnews&utm_source=facebook.com&fbclid=IwAR1kgueBz7zmNHNN9XUkKgO5megFmpnyy5ywrxdM8Cg1csy151tSLLIDa94#l15147yjojo9ucllrtl


----------



## duriel (Oct 10, 2013)

I would speculate that his 'dropper post' could be just as or more important to his win. With the larger disks, his modulation would be slightly improved, but how much time are they really on the brakes? When I went to disks, I really liked the improved feel, would slightly larger disks improve that by a significant factor?


----------



## Lombard (May 8, 2014)

duriel said:


> I would speculate that his 'dropper post' could be just as or more important to his win. With the larger disks, his modulation would be slightly improved, but how much time are they really on the brakes? When I went to disks, I really liked the improved feel, would slightly larger disks improve that by a significant factor?


I doubt it. I think the improved modulation is mostly because they are hydraulic rather than mechanical.


----------



## nova_rider (Sep 23, 2005)

103 said:


> A race winning bike does.
> 
> 
> https://www.cyclingnews.com/news/a-dropper-post-wasnt-mohorics-only-tech-hack-for-milan-san-remo/?utm_medium=social&utm_campaign=socialflow&utm_content=cyclingnews&utm_source=facebook.com&fbclid=IwAR1kgueBz7zmNHNN9XUkKgO5megFmpnyy5ywrxdM8Cg1csy151tSLLIDa94#l15147yjojo9ucllrtl


Kids, don't try this at home - Remember, I'm a professional.


----------



## nova_rider (Sep 23, 2005)

duriel said:


> With the larger disks, his modulation would be slightly improved,


No. You have it backwards - the larger disk would actually result in worse modulation due to the increased braking power with the same lever force applied.


----------



## overl0ad (Feb 16, 2021)

nova_rider said:


> No. You have it backwards - the larger disk would actually result in worse modulation due to the increased braking power with the same lever force applied.


i don't think modulation will change, just requires that the rider is more aware of what's going on a have better control.


----------



## duriel (Oct 10, 2013)

I changed my mind, modulation would be worse. So square one.... dropper seatpost!!!!! for the WIN!!!!!


----------



## nickyburnell (6 mo ago)

Peak Torque (youtube) has created an adapter to do just this. Fade is a massive issue for 100kg plus riders with a loaded or heavy bike. If you don't think so then you don't go downhill fast enough. (see anybody can make sweeping statements). I come from an engineering background, I've worked on trucks, cars, hydraulics and built a ton of motors so my Shimano 160 hydraulics are set up fine. New rotors, new metal pads. The front is rubbish. Check out the Peak Torque adapter, he's a proper engineer and heavy. Shame he champions Chinese stuff sometimes but that's his consience not mine. Not cheap but I'm getting one


----------



## overl0ad (Feb 16, 2021)

that setup is actually cleaner than the discord ones i got

def better feel and modulation from the 180's


----------



## duriel (Oct 10, 2013)

If there is greater modulation with 180mm rotors, that would mean that the total braking force (TBF) decreases as braking area/rotation (BAR) increases.
Where BAR = braking area of contact per rotation/area of brake pad
Which would mean bigger roto's would produce less maximum braking power unless the brake pads are increased in size.

Since it is impossible to change the maximum brake pad pressure (from the piston) without changing the calipar to multi pistons or larger pistons. I am interested in determining if with the same piston, will the TBF increased more by increasing the brake pad size or reducing it. I'm thinking the TBF will be reduced with a reduction in brake pad size even if the brake pad pressure is increase proportionally (due to the smaller pad size). Or expressed another way, the area of the brake pad and area of the brake disk is more important than the actual brake pressure since that pressure is limited by the master cylinder.


----------



## overl0ad (Feb 16, 2021)

i'm talking about leverage and not braking force

correct, total pressure does not change, but amount required does. so with a larger rotor, i need less force to scrub off the same speed.

maybe we are talking about the same thing but using different terms.


----------



## duriel (Oct 10, 2013)

My comments were not really directed to you completely. But from what you said on your 2 posts, your modulation is worse, braking power is more. Your brakes have become more touchy which is the opposite of controlling modulation, understand? Look up the definition of the words.
I'm trying to determine something else for another bike I'm working on and is not related to rotor size.


----------



## overl0ad (Feb 16, 2021)

Feel of brakes is subjective no?

I like brakes which are sensitive cos that’s how I ride/drive

others may prefer to have to pull hard before anything happens, or prefer the feel of a pair of RX4+. 

I get better control on this setup


----------



## Finx (Oct 19, 2017)

I have the ideal bike to use 180mm front rotors on. It's a Class III Trek Domane HP E-Bike that I use for commuting (30 hilly miles in each direction). It's not a commute I do daily, but I've managed almost 2000 miles over the last two years with it.

The bike is _really_ heavy, between the bike/frame/motor/battery/panniers/trunk bag/40mm Schwalbe Marathon Supreme Tires, and then add my fat @$$ in, and going down big hills is quite an adventure.

So this thread inspired me to try putting 180mm rotors on the front.

I started by ordering a Shimano Ice Tech 180mm rotor and the Peak Torque 180mm adapter.

Today I finally got around to installing it.

I'm not sure why, but for some reason, my setup did not require any additional adapters. I stacked the Peak Torque adapter and the standard Shimano adapter (that came on the bike for 160mm) and then put the rotor on the wheel. After installing it, I realized the caliper was too high and the pads were barely getting any bite on edge of the rotor. So I took the Peak Torque adapter back off and just used the adapter that was already on the bike, and it worked find with the 180mm rotor.

I rode it around and bedded in the brakes, and even with minimal bedding in, the front brake feels significantly more powerful with the 180mm rotor than the 160 did. I didn't ride it enough to do any kind of full analysis of feel, or any other non-quantifiable metrics, but there was a definite improvement in the power of the front brake.










Edit to add: Yes, I double checked, this rotor is definitely 180mm (it's stamped on it if you zoom in) and the old rotor was definitely 160mm. I also compared the 160mm adapter on this bike (which is labeled 160mm/180mm with one from another bike that only says 160mm on it and they are identical. I'm not entirely sure why this setup supports both 160mm and 180mm with the same caliper mounts, but it does.


----------



## overl0ad (Feb 16, 2021)

there are 2 different drilling / mount points on forks.

the spacing is the same, but one is higher then the other up the fork. 

most comminuter / touring / gravel bikes will let you use 160/180 via the shimano mount. road bikes will let you use 140/160

that's def a 180 rotor in your pic (the 140/160 have 4 arm carriers, the 180/200 have 5 arms)

to build on this info. IF you wanted to go 200/203 for any reason, you'll need the adaptor i believe. i haven't tested it, and won't be testing it, but logic says that the way to go.


----------



## Finx (Oct 19, 2017)

overl0ad said:


> there are 2 different drilling / mount points on forks.


This fork has only one set of holes. 

You can see where the profile of the fork is raised and flat for the adapter to mount.


----------



## overl0ad (Feb 16, 2021)

sorry, i meant that there are 2 standards which are chosen from.

unlikely to find both standards on the same fork.


----------

