Disc Brakes on a C59

[Master50]

So you're going to have to have a wet weather bike and a fair weather bike? And how hard can you really brake with the traction available with 20-23mm tires in the wet? (In my experience with aluminum rims in the wet, I have too much stopping power for 23mm tires. Disc brakes would be complete overkill for the conditions.) You'd have to run wider tires to make the disc brakes worth it, whose weight probably wouldn't appeal to someone trying to get UP the climb as quickly as possible.

Ultimate stopping power is really a tuneable and often irrelevant spec on disk brakes for bikes discussions.
Every disk system needs to be tuned for the application and I think we all agree that road bike brakes are strong enough. It is in applications where modulation can be an advantage. While threshold braking is not a skill I seek to learn, in the right hands skilled braking can gain advantages. We know that carbon rimmed wheels are not the greatest braking surface and certainly a disk brake is much more predictable and in the right hands the rider can use the brakes closer to the traction limits than rim brakes. For the rest of us? Maybe our wheels will last too long?

 

[42x16ss]

Now with discs, people who have never lifted the rear wheel under hard braking can have even more stopping power.

This made me laugh pretty damn hard when I first read it, then I thought back to Oscar Pereiro's crash in the '08 TdF. One thing that disc brakes will prevent is burping clinchers/loose tubulars caused by hot rims after frequent heavy braking.

Sure, it's not an issue for 99% of riders but I bet for guys like Nibali, Samu, Cancellara and Gilbert they can't come soon enough.

 

[dsut4392]

So you're going to have to have a wet weather bike and a fair weather bike? And how hard can you really brake with the traction available with 20-23mm tires in the wet? (In my experience with aluminum rims in the wet, I have too much stopping power for 23mm tires. Disc brakes would be complete overkill for the conditions.) You'd have to run wider tires to make the disc brakes worth it, whose weight probably wouldn't appeal to someone trying to get UP the climb as quickly as possible.

Why would you need a rim brake bike for fine weather when discs work better than rim brakes in fine weather too?

I'm running a front disc on my commuter with 1" slicks (i.e 25c equivalent) and it's a notable benefit over rim brakes, wet or dry. Less force required for equivalent stopping power, much better modulation.

Peak usable braking power is probably little different between rim or disc (as it's limited by the tire/road interface), but you get that peak almost instantly with discs and have much more modulation, and it makes a real world difference in stopping distance and control.

A major limitation in braking in wet conditions with rim brakes is not the coefficient of friction between the tire and the road, but between the brake and the rim. Although peak friction can give you just as much braking power as discs, it can take some time (seconds that feel like minutes!) before the brakes start to bite on the rim and how progressive the 'bite' is can be highly variable.

As for how hard you can brake in the wet on 23c tires, quite hard indeed in a straight line (and the vastly superior modulation [NOT power] of discs helps too). There is plenty of traction available from your front wheel, and tire width is not a limiting factor in braking (especially in the wet).

 

[simo1733]

Well, don't bank on it. That's practically too much braking power for the road racer. Someone's going to come out with a smaller rotor that will sweep big-money consumers off their feet.

Also note, Colnago's got the disc version of their 'cross product posted too. Talk about overkill!

I'm assuming the Colnago carbon is an OEM product which means you should see a couple more brands releasing a similar bike in 2012 until the bigger OEM's are done waiting for some standards to settle and Shimano to be up to full-speed on producing the levers. Even then supply of the lever mechanism will be constrained for a while.

C59 isn't an OEM product.

 

[rgmerk]

So you're going to have to have a wet weather bike and a fair weather bike? And how hard can you really brake with the traction available with 20-23mm tires in the wet? (In my experience with aluminum rims in the wet, I have too much stopping power for 23mm tires. Disc brakes would be complete overkill for the conditions.) You'd have to run wider tires to make the disc brakes worth it, whose weight probably wouldn't appeal to someone trying to get UP the climb as quickly as possible.

I'd ride the disc brake bike all the time. A top-end bike build, particularly for a small-size non-aero frame, will be way under the 6.8kg limit these days. Even with an extra 200 grams for the discs, you could still be under. As such, I can't see why you wouldn't ride the disc brake bike, seeing the braking is still going to be slightly better than the rim brake version, and you don't run the risk of popping a tyre from overheating brakes going down a steep descent.

Even assuming aluminium braking surfaces, it's not the power in the wet that's the issue, it's the feel. Disc brakes give you consistent feel and instant stopping power, and that's a very reassuring feeling.

And carbon is another story entirely. Carbon rims, wet weather and braking simply do not go together well.

 

[RDV4ROUBAIX]

The funniest part of all this is the fervent denial or inability to accept changes from the usual suspects here, making ridiculous statements that d-brakes have "too much power for road bikes", or are "too heavy", or "finding a solution for a problem that doesn't exist", same old tired arguments. These are the same people who protested clipless pedals and indexed shifting in the 80's, went up in arms when brakes and shifters were integrated in the 90's, considered hunger strikes when head tubes went to 1 1/8" and tapered. If I had a dime for every time some old curmudgeon complained about new tech or tech migrating from mtb to road, I'd be a millionaire. I'm going to take a guess and say I'll bet most of the d-brake deniers don't even own a carbon wheel set, therefore they know everything about this topic. Logic at it's finest.

 

[bladerunner]

The funniest part of all this is the fervent denial or inability to accept changes from the usual suspects here, making ridiculous statements that d-brakes have "too much power for road bikes", or are "too heavy", or "finding a solution for a problem that doesn't exist", same old tired arguments. These are the same people who protested clipless pedals and indexed shifting in the 80's, went up in arms when brakes and shifters were integrated in the 90's, considered hunger strikes when head tubes went to 1 1/8" and tapered. If I had a dime for every time some old curmudgeon complained about new tech or tech migrating from mtb to road, I'd be a millionaire. I'm going to take a guess and say I'll bet most of the d-brake deniers don't even own a carbon wheel set, therefore they know everything about this topic. Logic at it's finest.

Well put RDV4Roubaix except for one thing : you'd not be a millionaire but a TRillionaire by now!!!

 

[steelciocc]

Thanks for respecting a different viewpoint RDV.

 

[Gaear Grimsrud]

RdV: only time will tell if the C59 is the beginning of the move to discs.

If I had a dime for every "game changer" that was just a marketing fad. Some innovations really are that: clipless pedals, brifters (both of which I adopted immediately). Some aren't.

 

[Gaear Grimsrud]

RdV: only time will tell if the C59 is the beginning of the move to discs.

If I had a dime for every "game changer" that was just a marketing fad. Some innovations really are innovations: clipless pedals, brifters (both of which I adopted immediately). Some aren't.

 

[DirtyWorks]

..These are the same people who protested clipless pedals and indexed shifting in the 80's,....

Disagree. I think you and many others breathlessly awaiting new ways to blow ridiculous amounts of money on the next cycling fad like to paint with a very broad brush.

If I had a dime for every time some old curmudgeon complained about new tech or tech migrating from mtb to road, I'd be a millionaire. I'm going to take a guess and say I'll bet most of the d-brake deniers don't even own a carbon wheel set, therefore they know everything about this topic. Logic at it's finest.

Really? Cycling is truly the new golf and carbon wheel sets are the greens fees.

You and many others are legitimizing the notion that winning races requires the fastest way to go slow. Where are these road/'cross bike races where going slow wins an event? Are braking contests the newest kind of bike race?

Your comments are the reason the competitive sport will remain an irrelevant niche in the U.S. The relentless pursuit of mostly nonsense gear for club ride FASHION glory drives interested people away from the sport by the hundreds. Picture characters from Idiocracy rolling around on carbon fiber wheels....

 

[DirtyWorks]

and you don't run the risk of popping a tyre from overheating brakes going down a steep descent.

Is this a frequent occurrence for you and your circle of friends? Where is this descent that is so steep the heat from braking blows many cycling tires off of wheels?

It's okay to want discs on a racing bike to be the Gear King for a month. Just call it what it is and stop making stuff up to justify spending the money.

 

[FignonLeGrand]

Yes, I'm sure a standard to accommodate discs will proceed as smoothly as the bottom bracket standard(s).

It's funny that some of the same people who scoff that pros are paid to ride "plastic" frames are rubbing their hands at the prospect of pros validating their favorite bits of unnecessary tech.

I'm sure discs have a future, just as electronic shifting has a future: as a niche for those who can't spend enough on their bicycles.

haha I agree there will be some toing and froing as everyone tries to get one up on the other manufacturers. I did say direction of all bikes, I dont actually think current disc brakes will be the long term outcome for road bikes, they seem a little too agricultural for my liking. But I really dont think its a gimmick, once UCI allowed on cross bikes it seemed clear to me that this was going to be the next step. Cross provides a great pilot study on how best to proceed.

I also believe electronic gear changers are the future...............for urban e-bikes. We might all laugh but my 80 year old neighbour loves her battery assisted bike and with an electronic shifter she would be even more comfortable. Whereas I wouldnt even think of going electric.

 

[Gaear Grimsrud]

But I really dont think its a gimmick, once UCI allowed on cross bikes it seemed clear to me that this was going to be the next step. Cross provides a great pilot study on how best to proceed.

Possibly, but there are a few differences in 'cross: 1) foul conditions are routine; 2) tires are wider; 3) bike weight/aerodynamics are less important.

An article that was quite positive about discs on road bikes had this to say:

To transition, manufacturers will need to rethink road frames and wheels from the ground up. Bikes may initially be anywhere from 100 to 500 grams heavier than similarly equipped bikes with rim brakes. The effect that disc brakes might have on aerodynamics is also largely unknown, although the results of some tests were not encouraging: "Disc brakes were tested in the Texas A&M wind tunnel a decade or so ago, and they sucked," said Damon Rinard, Cervelo's senior advanced R&D engineer. He acknowledged that the company is considering a new round of wind-tunnel testing with discs.

The industry also needs to agree on standards for the new brakes, or risk confusing consumers with competing standards, just as too many bottom-bracket standards currently saturate the market. Charles Becker, SRAM's category manager for road and triathlon, says he hopes the industry can find middle ground. But SRAM isn't waiting. It's undertaking experimental development of road-bike disc brakes. "From both SRAM's and the industry's perspective, I'd like to see it happen," says Becker. "I think there's a lot of performance to be gained."

I'll believe the last sentence when I see the majority of grand tour bikes using discs on mountain stages.

 

[DirtyWorks]

An article that was quite positive about discs on road bikes had this to say:

I'll believe the last sentence when I see the majority of grand tour bikes using discs on mountain stages.

If the UCI allows it, they'll use discs regardless of the performance benefit. Why? Because it will sell WAY more disc kits to RDV4Roubaix and his pals. It's very hard to know what the UCI will do though.

 

[rgmerk]

Is this a frequent occurrence for you and your circle of friends? Where is this descent that is so steep the heat from braking blows many cycling tires off of wheels?

It's okay to want discs on a racing bike to be the Gear King for a month. Just call it what it is and stop making stuff up to justify spending the money.

No, it's not frequent, but you only want to have a downhill blowout at speed once.

The descent I would like discs for is Mount Baw Baw.

I did the climb late last year. Coming down, I stopped about half-way down to check the rims, and nearly burned my fingers. It took several minutes for them to cool down.

And, yes, mates of mine have had tyre blowouts on descents.

 

[Gaear Grimsrud]

"Tubular tires very rarely roll when they are professionally glued. It is seen more in cyclocross than in any other discipline."

 

[Gaear Grimsrud]

And, yes, mates of mine have had tyre blowouts on descents.

Any incidents in the pro ranks someone can point to?

 

[User Guide]

I don't get the build they did. I see Shimano DA DI2 but with some custom Colnago brake levers. Are they making their own brifters for use with DI2?

The Brakes/levers are formula,who make some very light and great performing xc brakes.But you can get brakes already that work with normal shifters(use a little piston too change cable pull too hydraulic, hopes v twin for example)

 

[dsut4392]

Yes, I'm sure a standard to accommodate discs will proceed as smoothly as the bottom bracket standard(s)

Yeah, the same issue is a big problem in the MTB world what with IS and post mount, centrelock and 6-bolt, and a squillion different rotor sizes. That's why mountain bikers gave up on them (as well as them being a silly marketing driven fad of course).

What's that? Mountain bikers didn't give up on discs? They learned to live with multiple standards because you can easily get an adapter between just about any possible variants. So it's really not a problem?

[using a shimano post-mount caliper with a $5 no-name IS adapter to fit a 3rd party 185mm (non-standard size for shimano for the noobs) 6-bolt disc: NOT a problem in the real world]

 

[Gaear Grimsrud]

That's why mountain bikers gave up on them (as well as them being a silly marketing driven fad of course).

And because they both have two wheels, we can safely assume that if discs caught on with MTBs, the same will happen for road bikes.

 

[Notso Swift]

No, it's not frequent, but you only want to have a downhill blowout at speed once.

The descent I would like discs for is Mount Baw Baw.

I did the climb late last year. Coming down, I stopped about half-way down to check the rims, and nearly burned my fingers. It took several minutes for them to cool down.

And, yes, mates of mine have had tyre blowouts on descents.

Robert
I bet you also have some mates who have had a Tub roll on them as well. not frequent, but it does happen.
I still stand by the fav that Carbon rims should only be tubular!
As for Baw Baw, that top half is seriously tough, 6km at well over 10%, so if you are going to do it anywhere coming down then that is the place!

I am not anti disks, but I am suspicious that this is something we don't actually need but the marketers are driving for.

 

[RDV4ROUBAIX]

Thanks for respecting a different viewpoint RDV.

I have the utmost respect for different views, but all the points you guys are trying to make in the last 3 or 4 threads on this subject are wrong.

RdV: only time will tell if the C59 is the beginning of the move to discs.

If I had a dime for every "game changer" that was just a marketing fad. Some innovations really are innovations: clipless pedals, brifters (both of which I adopted immediately). Some aren't.

Time is telling, and from where I'm sitting just in the past year I've seen and heard things that make me believe that these changes are coming sooner than we think. The C59D isn't really THE game changer, just the most visible. The small indie frame builders have been building d-brake road race bikes for years.

Disagree. I think you and many others breathlessly awaiting new ways to blow ridiculous amounts of money on the next cycling fad like to paint with a very broad brush.

When you come back to planet earth sometime compare pricing on a bb7 set to Dura Ace or Super Record calipers and tell us all about that ridiculous difference.

Really? Cycling is truly the new golf and carbon wheel sets are the greens fees.

That's right, carbon completely changed the demographics of people who are into racing at club levels or just race bikes. Nothing new here.

You and many others are legitimizing the notion that winning races requires the fastest way to go slow. Where are these road/'cross bike races where going slow wins an event? Are braking contests the newest kind of bike race?

Insane much? How do you race anything without decent brakes?

Your comments are the reason the competitive sport will remain an irrelevant niche in the U.S. The relentless pursuit of mostly nonsense gear for club ride FASHION glory drives interested people away from the sport by the hundreds. Picture characters from Idiocracy rolling around on carbon fiber wheels....

You guys are too much, especially you DW. You sound like you need a hug. I can't take all the credit for why bike racing can't get better in the US, Pffft!!! I think most of the credit goes to the USAC for putting gear limits on Jr. racing when their counterparts in the rest of the world are allowed to race normal gears. Why do you think every time a U.S. kid goes to race Kermesses in Belgium to cut their teeth they get shelled all the time? Everybody else is pushing bigger gears, much earlier than us.

Anyway, disk brakes are nothing but advantageous for carbon race wheels. They're coming.

 

[Master50]

Rdv4
You had me right up to gear restrictions. Eddy Merckx is still one big restriction proponent and gear restrictions come and go but they certainly are enforced in Europe. Yes races do exist without restrictions but that is not the primary reason American kids get shelled. Experience! Still got to have that.

 

[RDV4ROUBAIX]

... and jet lag.

Forgot to mention. Road disk brakes will make carbon wheels suitable for daily use, something they aren't in their current rim brake torture devices state.