The debate over hydraulic disc brakes in the pro peloton

[leftcoaster]

http://velonews.competitor.com/2014/08/ ... ton_340905

[Rolf]

The article suggests there's no questioning it's better technology, and that there's a consensus that general adoption for road bikes is inevitable—despite resistance from the pros.

Some interesting bits:

The UCI ... believes that a wholesale swap is the safest route, when the technology is ready. This would prevent riders from running into each other due to a huge disparity in braking power, especially on high- speed descents.

(Something I've occasionally noticed on a wet Tripleshot ride. )

The UCI will run Paris-Roubaix as a road disc test event in 2016...

Pros are most validly concerned about getting cut or burnt by hot, sharp, spinning discs in high-speed pileups. But the other concerns are negligible—or could be addressed by further engineering or standardization across the peloton—and are certainly not significant concerns for amateurs: weight (100-300 gms?); aerodynamics (pshaw! — okay, mayyybe understandable for TTs); and slower wheel changes.

It's mystifying to me why all those high-end bikes at Pro City and La Bicicletta have rim brakes. Particularly when consumers of such bikes are equally willing to shell out thousands for carbon wheelsets that come with built-in guilt every time one hits the brakes, knowing the carbon braking surface is being compromised.

I guess if you spend $5+K on your bike, you emotionally want it to be as close to what you see tearing down the Alps and Pyrenees under Cancellara and Sagan. And the marketing of these bikes bears that out. But instead, here:

Road discs, and ... the UCI, have reversed the [usual order of sport technology being led from the front.] The technology is trickling upwards, from the amateur realm, and from the dirt, to the upper echelons of road racing.

[leftcoaster]

Here are some of the pro's opinions......

http://velonews.competitor.com/2014/08/ ... ate_341014

For....

I’d love to have road discs someday. I’m all for the progression of the sport, and it’s only beneficial. I think it’s the next step

I’ve never used [discs] before, except on a mountain bike. I’d love to try it in training, and in a race. I think it has its advantages — you see how scary it is to go downhill in a race with no brakes or almost no brakes. The problem now with carbon rims is 50 percent of your brake power is gone when it starts raining so it’s maybe a good thing that they will allow it, or should allow it.

Against....

You have to strengthen the forks, the wheels, you need more spokes in the wheels

I think, for going under the rigors of full ProTour racing, it’s a long ways to go. You have to think about other things in mass crashes… Have you ever touched a disc brake when it’s hot? It’s hot, so when you have mass crashes you’ll start having disc brake burns on your body

I don’t want to jump out of the car and see a guy with his femoral artery sliced. If there’s 25-30 guys on the floor

[Rolf]

That last little bit of alarmism is actually from a Garmin mechanic, not a rider.

If they really wanted to make crashes safer, they'd cover up that nasty toothed ring thingy that is bound to shred some flesh in pileups:


Here are some further interesting articles on this disc-ussion from the past year:

http://www.bicycling.com/bikes-gear/bik ... isc-brakes

http://cyclingtips.com.au/2013/10/disc- ... ture-hold/

[agoraphobic cyclist]

Pros are most validly concerned about getting cut or burnt by hot, sharp, spinning discs in high-speed pileups.

That's a red herring. Discs have been CX legal since 2010, and I've yet to hear such horror stories.

...the other concerns are negligible—or could be addressed by further engineering or standardization across the peloton—and are certainly not significant concerns for amateurs: weight (100-300 gms?); aerodynamics (pshaw! — okay, mayyybe understandable for TTs); and slower wheel changes.

The weight aspect is funny to me, when they're strapping weights to the bike to make the 15 lb limit... Aerodynamics, OK but there's a point where we can't go any faster so I'd rather see difficulty increased so we're seeing the athlete rather than who can get the best equipment. Like how swimming banned the particular model of swimsuit...

The guilt of the brake surface eroding on carbon isn't really new - rim brakes have always had the issue of erosion so we watch the rims don't get concave. But what I learned recently is the inherent danger with rim brakes on carbon. When I look at the tech, discs:

• Perform better
• Less danger of causing a crash
• Carbon rims last longer

...for currently a weight and aero penalty.

The wheel swap aspect, coming from BB7s, isn't an issue to me. While single piston, you can pull someone off the street and they can figure out how to dial in BB7s in minutes. Cantis to me have always been a black art, and when V brakes came in - cantis weren't worth the time to learn.

I'm not a cycling purist, and discs make a lot of sense. For me, I want road discs to be more common because I'd rather spend the money on the frame and save by swapping wheels. And once more common, there'll be more competition in wheelsets - working to bring the weight down.

[mfarnham]

If a wholesale swap is the safest route (according to the UCI), then presumably we'll do that in Tripleshot too, right?

When can I tell my wife that I'm being forced to buy a new road bike?

Martin

[Josh.E]

The almost universal assumption by non engineers is that disc brakes will simply work better on road bikes than rim brakes, when the fact is getting them to work well enough to release has been the driving factor that has delayed their release until now.

Right now, disc brake develpment for road a purely market driven technology, not a performance improvement driven technology. The bike manufacturers recognized the perception that consumers have (extrapolated mainly from low speed performance on mountain bikes, and now cx bikes) that disc brakes are superior to rim brakes. So they tasked their engineers with designing disc brakes for road bikes. Problem was that the engineers couldn't get the disc brakes working well enough for road bikes. The problem was heat dissipation in disc sizes that would be accepted on a road bike. In low speed mountain biking, there is not a lot of energy that needs to be dissipated. On a 40km/h descent there is exponentially more energy. The rotor and pads need to dissipate almost 2.5 times as much heat to slow a rider from 40 to 30km/h as it takes to slow a rider from 20-10km/h. So the disc brakes would fade due to heating and completely stop working on high speed descents.

There's been talk of disc brakes coming soon on road bikes for 5 years now There's reason why it's taken this long for the first road bikes to start coming out with them.
IMO, this industry has a history of releasing new technology before they are ready in the rush to be the first. It's a bit similar to early carbon fibre wheels and frames failing as they got released before the technology was proven ready for prime time.
The technology may very well get there and surpass rim brakes eventually, but personally, I'd rather not be a beta tester for something like friction fade as I'm descending mt washington at 70km/h.

This article from a few years ago is a good one.
http://www.bikerumor.com/2012/02/14/roa ... they-work/

This article has a much more positive spin of the state of the technology (as one would expect from SRAM as they release them)
http://road.cc/content/news/80972-why-s ... are-future

[AdamD]

That's a red herring. Discs have been CX legal since 2010, and I've yet to hear such horror stories.

Really disagree with that, in cross your rarely see multi rider pileups. More so one or two guys sliding out in a corner.
If youve ever experienced this you probably are not keen on 80 sharp burning rotors added to the mix

If they really wanted to make crashes safer, they'd cover up that nasty toothed ring thingy that is bound to shred some flesh in pileups:

I do have a nice scar in my shin from a chainring in that crash actually.