How soon will disk brakes be used on road racing cycles?



Thylacine

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Geez, much of an ego vspa? You think the 'racers' were responsible for carbon rims, STI, and ceramic bearings, oversize headtubes, oversize crank spindles? Designers and Engineers were. We make it, pro racers STFU and use it. Their job is to STFU and ride and sell the companies' ****, they are little more than rolling advertisements.

You also clearly missed the Tour 2 days ago, where Hushovd lost time on the climb owing to the fact he's a sprinter and stuff, and then managed to make up the time on the descent, to win the stage. Imagine how much more time he would've made up if he could brake 50% later on those dozens and dozens of corners and switchbacks.

There's a golden rule in racing "You can only go as fast as you can stop", and as most races do as much climbing as they do descending on any given day, it's time the focus the design away from climbing and superlight parts that have essentially no quantifiable benefit, and think about other areas where the breed can be improved.

Brakes is one of those areas. Clearly. It's not even a debatable thing.

All you have to do to get a first hand illustration of how stupid rim brakes are, is ride an MTB with them, then switch to one with Discs. I've had hydraulic discs on my MTB's for probably 15 years, and nobody would EVER go back to rim brakes. They're HATEFUL. Increased complexity and maintenance? RUBBISH. Set and forget, change the fluid maybe once a year, it's just as quick as changing a cable. NEVER had any failure whatsoever either.

Electronic shifting and hydraulic discs on road bikes are the inevitable future. Like with everything, there'll be those that aren't the Early Adopters and that's fine, but Ludditism for it's own sake is pretty damn annoying, especially considering I'd place good money on the fact that these same people aren't exactly racing lugged steel frames with friction shifting.

Originally Posted by vspa .

fast descender jersey ? non sense,
from all your posts i can tell you have no racing experience whatsoever,
if you do, go to europe and challenge the guys in a descent with your disc brakes, i guarantee that you will get drop in a minute against those guys,

i would also elaborate why not to use them on a peloton, something that you also seem to misunderstand, racing get nervous and you have little room to maneuver, sometimes your reflexes act faster than the blink of the eye, with disc brakes you would cause twice the crashes than you see today, in fact a good cyclist will almost avoid using the brakes in the peloton by measuring pedal strokes and looking for tiny spaces where to go,

that said, it may be the case that disc brakes could be one day introduced on the road but just remember that when a proven good new technology enters the market it is adopted almost immediately by every bike maker and every cyclist and disc brakes have been around for a while already,
 

finnrambo

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Jun 6, 2010
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disk brakes will be on the road scene when the disk, pad, hose, lever, master cylinder, piston and those other parts are all carbon and boron, they will never make it past cat.4 though because they can cause crashes like vspa said, I've have been crashed twice from riders hitting their brakes for fear of corners and drafting. When disks come out I'll be the first guy to quit
 

Thylacine

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Nothing like blaming the equipment for rider error. I doubt there's a regulatory body on earth that would ban a piece of equipment solely because it works better than the old version.
 

dhk2

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Aug 8, 2006
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Originally Posted by doiturself .



1. Why do you say "never"?

2. Why do you think they will be "too heavy"? Are the engineers at Shimano, et. al. incapable of making a road-racing specific disk brake system of appropriate weight? One of my riding buddies, who owns a LBS, has a carbon fiber road bike which weighs in at 15 pounds. It uses the Shimano electronic shifting system. If an electronic shifting system can be designed and used on a modern road bike which comes in at 15 pounds (inconceivable ten years ago), why not disks?

3. Why do you think the advantages of disk brakes, which are so obvious on every other type of vehicle or industrial application (airplanes, cars, trucks, motorcycles, machinery), do not extend to bicycles? Do bicycles operate in an alternate universe inhabited by Luddites?

There is one category of jersey not currently awarded in the Tour: that for fastest descender. The climbers get one, the sprinters get one, but not the fastest guys on descents. That's because the antique brakes are not up to aggressive corner entry. Put some great brakes on these bicycles and you will see an entirely new category of speed, and the climbers will not have an advantage. Many minutes can be made up on a long descent where relatively fade-free disks are used, which don't melt the glue on the tubular tires and allow consistent control over corner entry speed and brake modulation through the turns.

Disks will be a huge game changer and that's why they are being resisted. But in the end racers are going to have to have the whole skill set: climbing, descending, sprinting, in order to be competitive.
1. I wrote that I've never seen any article or report to claim a competitive advantage for road race bikes. My question was, have you?

2. Any extra grams added to a race bike must be justified. Discs will always be heavier than the current system, which uses the rim itself as the disc, combined with calipers that are mounted on already-existing hard points. Any caliper designed to operate on a smaller disc will have to exert more clamping force to provide the same braking force at the tire, so it would likely be heavier as well. Offsetting the extra weight of the disc rotor can't be accomplished by shaving down the rim, since (for clinchers) the rim sidewalls have to be strong enough to resist tire pressures.

3. Road race bicycles already use "disc brakes", which are lighter and offer better braking control than old-school coaster brakes and drum brakes. Why do you think adding a seperate, smaller disc and a heavier caliper requiring more force would be worth the extra weight?
 

doiturself

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Jul 4, 2011
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1. The advantages of a disk brake over any other design are so well-known that yet another article proving them again hardly seems necessary. Their current use on downhill racing bicycles and now cyclocross should be sufficient proof of their superiority on bicycles, though.

2. This presumes that somehow road bikes will be using the kind of heavier systems now seen on MTB (although the Shimano XTR is very light by any standard). Clearly, a system designed for a 14.9 pound bicycle instead of a 29 lb. machine will be far lighter still. This kind of objection seems to be based on the notion that disk brakes cannot be made any smaller or lighter than those currently available, which is erroneous. Also I must reiterate that the rim/wheel assembly for a disk system would be much lighter as it would not have to function as a braking surface. Carbon fiber or composite materials could be used for wheels without compromise when disk brakes are part of the overall wheel/brake system, thus making the wheel itself much lighter.

3. A rim is not a disk. It is a hoop and the big problems with rim brakes are well understood but since we are rehashing everything, let's go over them again: a) the rim has to be much thicker to handle braking as well as be strong enough to function as a wheel; b)heat buildup in the tire can cause sudden failure; c) the rubber pad material used for rim brakes has terribly uneven and unpredictable performance under hard braking as compared to the advanced materials used in a disk brake pad.

Originally Posted by dhk2 .



1. I wrote that I've never seen any article or report to claim a competitive advantage for road race bikes. My question was, have you?

2. Any extra grams added to a race bike must be justified. Discs will always be heavier than the current system, which uses the rim itself as the disc, combined with calipers that are mounted on already-existing hard points. Any caliper designed to operate on a smaller disc will have to exert more clamping force to provide the same braking force at the tire, so it would likely be heavier as well. Offsetting the extra weight of the disc rotor can't be accomplished by shaving down the rim, since (for clinchers) the rim sidewalls have to be strong enough to resist tire pressures.

3. Road race bicycles already use "disc brakes", which are lighter and offer better braking control than old-school coaster brakes and drum brakes. Why do you think adding a seperate, smaller disc and a heavier caliper requiring more force would be worth the extra weight?
 

swampy1970

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Feb 3, 2008
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Originally Posted by doiturself .

This is from the "Death Ride" site:

Use your brakes sparingly and evenly on descents, rims can heat up from brake pad friction. Watch for overheating brakes.

I'm with Dave on that one - a few of the descents on that ride only require very infrequent application of brakes...

There was a comment about tubular tires going away soon - that isn't gonna happen. The rims are stronger, due to a lack of a bead wall required for clinchers/tubeless tires and lighter too. Stronger - lighter... why give that up? The ride quality is better too. You think that tubless tires ride great - go ride a high quality tubular tire thats been properly installed and glued. Heaven. Tires and glue melting - that isn't going to effect 99.999% of folks that race and the 0.0001 that it does is nearly always due to incorrect glueing practise. It'd be interesting to see which would be the most frequent offender - tubular tires rolling due to glue melting or clincher tires blowing off the rim due to excessively heavy braking loads and the subsequent heat. I'd say the tubulars would win that battle. That said, I've never rolled a tubular that I've glued and haven't had a clincher tire blow of the rim even when riding a loaded touring bike on silly steep hills in Wales.

The only issue I percieve with braking on a road bike at present is that some carbon rims may not provide the best braking modulation. Do you redesign the rim layup or do you redesign the brake because the rim is [email protected]?

You can make a disk brake more powerful than a regular dual pivot caliper however, if the current generation of racing brakes provides enough power at any speed to lock up the wheels even with smooth and gradual application of force on the brake lever, then the limiting point is the availability of traction between the tire and the road. Having more powerful brakes isn't going to help in the slightest. The required effort to use the brakes is minimal, so that really does away with the factor of reduced fatigue overtimes. Brake levers such as the Dura Ace 7900 are fully adjustable for reach - which makes this point even less of a factor.

You say that disk brakes are illegal - that's only for road racing. There's nothing from stopping you putting something together and performing tests to validate your beliefs. If you can put something together and get some meaningful data that proves positive for disk brakes on road bikes then the perception that they offer no advantage, that they'd make for slow wheel changes etc etc might start to change. If anything, go grab a setup from TRP or someone similar and give that ago now that the UCI have allowed disk brakes in cyclocross.
 

doiturself

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Originally Posted by swampy1970 .





I'm with Dave on that one - a few of the descents on that ride only require very infrequent application of brakes...

There was a comment about tubular tires going away soon - that isn't gonna happen. The rims are stronger, due to a lack of a bead wall required for clinchers/tubeless tires and lighter too. Stronger - lighter... why give that up? The ride quality is better too. You think that tubless tires ride great - go ride a high quality tubular tire thats been properly installed and glued. Heaven. Tires and glue melting - that isn't going to effect 99.999% of folks that race and the 0.0001 that it does is nearly always due to incorrect glueing practise. It'd be interesting to see which would be the most frequent offender - tubular tires rolling due to glue melting or clincher tires blowing off the rim due to excessively heavy braking loads and the subsequent heat. I'd say the tubulars would win that battle. That said, I've never rolled a tubular that I've glued and haven't had a clincher tire blow of the rim even when riding a loaded touring bike on silly steep hills in Wales.

The only issue I percieve with braking on a road bike at present is that some carbon rims may not provide the best braking modulation. Do you redesign the rim layup or do you redesign the brake because the rim is [email protected]?

You can make a disk brake more powerful than a regular dual pivot caliper however, if the current generation of racing brakes provides enough power at any speed to lock up the wheels even with smooth and gradual application of force on the brake lever, then the limiting point is the availability of traction between the tire and the road. Having more powerful brakes isn't going to help in the slightest. The required effort to use the brakes is minimal, so that really does away with the factor of reduced fatigue overtimes. Brake levers such as the Dura Ace 7900 are fully adjustable for reach - which makes this point even less of a factor.

You say that disk brakes are illegal - that's only for road racing. There's nothing from stopping you putting something together and performing tests to validate your beliefs. If you can put something together and get some meaningful data that proves positive for disk brakes on road bikes then the perception that they offer no advantage, that they'd make for slow wheel changes etc etc might start to change. If anything, go grab a setup from TRP or someone similar and give that ago now that the UCI have allowed disk brakes in cyclocross.
Agree with all you say, well put.

Power is not the issue or advantage; it is control, consistency, and efficiency.

It may well be that disks for road-racing cycles will have LESS overall stopping power than the rim brakes currently in use because as you said, it is entirely possible to lock up a wheel with current systems -- sometimes. But a great brake system, even a very powerful one, that provides consistent performance and very fine control and modulation will be a great advantage, as corner entry speed is the biggest factor in slowing a descending rider. A disk system with lighter wheels would allow later, more precise braking. This is a skill set not well-represented in the current field of top level Tour competitors but it will become a factor when better brakes are adopted.

The testing you suggested is already well underway on many fronts and we'll start to see the results soon enough. Obviously, Volagi is at the forefront in this respect; they call their cycles "endurance" bikes but based on the weights and components one can easily see how a competitive road race bicycle cannot be far off on that company's horizon. Here is a quote from Barley Forman, one of the founders, re: the efficacy of disk brakes on their line:

The other obvious highlight has to be the front and rear disc brakes. To us, it was a decision that made itself: is it better? Yes, in almost every way! Road bicycles are really the only hold-out to disc brakes – every other performance form of transportation currently available has adopted disc brakes for a reason – they are better. It’s obviously about safety and control, but also about going faster, with more confidence.

Once you try discs on a long twisty downhill, we’re convinced you won’t want to go back to rim brakes. Outside of that, they’re better in the rain, work with a broken spoke, work with a dented rim, work better with carbon rims (no heat build-up), won’t roll a tire on a hot day, fits larger tires, easier to change a flat (cleaner), last longer, consistent performance, etc, etc…

The remarks about "control" and "going faster with more confidence" are what will assure the appearance of disk brakes on bona fide racing cycles in the near future. But even now, one can ride a disk-equipped mountain bike or touring bike and savor the benefits of disk brakes on bicycles.
 

doiturself

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Originally Posted by vspa .

fast descender jersey ? non sense,
from all your posts i can tell you have no racing experience whatsoever,
if you do, go to europe and challenge the guys in a descent with your disc brakes, i guarantee that you will get drop in a minute against those guys,

i would also elaborate why not to use them on a peloton, something that you also seem to misunderstand, racing get nervous and you have little room to maneuver, sometimes your reflexes act faster than the blink of the eye, with disc brakes you would cause twice the crashes than you see today, in fact a good cyclist will almost avoid using the brakes in the peloton by measuring pedal strokes and looking for tiny spaces where to go,

that said, it may be the case that disc brakes could be one day introduced on the road but just remember that when a proven good new technology enters the market it is adopted almost immediately by every bike maker and every cyclist and disc brakes have been around for a while already,
Well, you are wrong there re: racing but there is no point in comparing past deeds. Great brakes are as important as a great engine and great suspension and re: bicycling they are the last holdout. Some others have already posted to that effect; the truth seems to be more to the point that road cyclists are not especially good on the brakes because the brakes are not especially good! Thus one would be rather cautious about pushing equipment and or speeds.

Peloton, descent, it makes no difference; a better braking system is an advantage. If a rider is too ham-handed to be able to use it, that is another thing and that is exactly why disk systems will be a game-changer; it will take a whole new skill set to be able to exploit them.
 

jpr95

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I'm sure that once disc brakes are allowed by UCI for use in pro road races that riders will simply have their mechanics install them the morning of the race and away they'll go. With the hundreds of thousands of dollars that teams spend on riders and bikes, and the great knowledge they already have, there would be no reason for them to do any sort of testing ahead of time. Riders won't want to practice with them at all because they're never concerned with a major change in equipment the day of a race. /img/vbsmilies/smilies/cool.gif

Jason
 

dhk2

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doitur, I find your responses less than convincing. Let me summarize:

1. The advantages are so obvious they don't need to be demonstrated or tested on road race bikes. So, I take that as a "no".

2. I didn't presume anything about the weight of a road bike disc system, and agree current MTB systems could likely be made lighter for road use. What I said was that a disc-brake system for road bikes will always add weight compared to the current caliper brake systems in use. That's a judgement on my part, based on the weight that could be shaved off the rim vs the extra weight of the disc, the stronger caliper and heavier hub and fork required to react the braking forces. The front wheel may also need to be strengthened to handle hub braking forces; certainly radial spokes like I use now wouldn't be an option. My opinion is that once all the extra weight is accounted for, the most expensive and exotic disc brake system will outweigh a cheaper standard rim-caliper system by a significant amount, enough that racers who have to climb hills won't buy them.

3. a: Disagree that the rim sidewall has to be much thicker to withstand braking wear. Clincher rims have to be thick and strong to withstand the force of the tire bead which wants to spread them out. Since clinching rims have pressure ratings now which aren't all that high (eg, Mavic @ 140 psi), I doubt much weight, ie, maybe 50 grams max could be shaved from the rims without risking tire blowouts.

b: Yes, agree heat buildup from braking on long descents can cause sudden failure in theory. Friends on tandems have hub brakes (drum or disc) in addition to their rim brakes on the rear wheels in order to reduce rim/tire heating on long descents. They use them as "drag brakes" to keep speeds down to 40 mph or less, when they could see 55-60 mph without any braking.....faster than they care to go on their touring tandems. I don't see any evidence that these are needed on single road race bikes. You really think it's a problem for road racing?

c: Disagree that the rubber pad has "terribly uneven and unpredictable performance under hard braking". My opinion is that most caliper brake systems (providing they are in good repair) are much better than the capability of the riders. We have a lot of fast, technical descents here, a few riders I know have the ability to exploit the braking potential of their caliper brakes.

Hey, no need to rehash your statements again just for me. To me, disc brake systems on a road bike are another one of those ideas that solve a problem we road bikers don't really have, and you haven't convinced me otherwise. But one thing I've learned here over the years is that you'll never convince everyone of anything:most discussions just end without changing anyone's mind.
 

jpr95

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Dhk2, I'm a little skeptical about your concerns with the spokes and how disc brakes would affect them. Even with rim brakes, there is still a huge transfer of force through the spokes. When the rim brakes grab the rim, the fork is still pushing forward with the momentum of the bike and rider on the hub and through the spokes. I don't know that there would be any difference. I think the forces on the spokes would be the same up to the point of lock-up/skid.

Jason
 

davereo

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Jun 17, 2010
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Originally Posted by jpr95 .

Dhk2, I'm a little skeptical about your concerns with the spokes and how disc brakes would affect them. Even with rim brakes, there is still a huge transfer of force through the spokes. When the rim brakes grab the rim, the fork is still pushing forward with the momentum of the bike and rider on the hub and through the spokes. I don't know that there would be any difference. I think the forces on the spokes would be the same up to the point of lock-up/skid.

Jason

Its the radial load of braking from the center of the wheel. Think of it as the energy tranfered when pedaling to get the rear wheel spinning ten times greater than you can pedal. Huge potentential for your wheels to countinue to roll as your hubs stop causing your spokes to just shear away. Mountain bikes and CX bikes equiped with disc brakes have high spoke counts due to this energy transfer.
 

doiturself

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A lot of interesting comments; really, I was interested in hearing the objections.

Disks are on the way; you don't have to use them but they're coming. Maybe it'll take a younger generation of riders not clinging to their guns and religion /img/vbsmilies/smilies/duck.gif to embrace them, but they are coming nonetheless./img/vbsmilies/smilies/biggrin.gif
 

doiturself

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Originally Posted by dhk2 .

doitur, I find your responses less than convincing. Let me summarize:

1. The advantages are so obvious they don't need to be demonstrated or tested on road race bikes. So, I take that as a "no".
Are you attributing that to me? Here is what I wrote; I certainly did not state no testing was needed, au contraire...my words from my initial response to your queries follow but it seems some have overlooked them (the bold face type is Barley Forman's words):

The testing you suggested is already well underway on many fronts and we'll start to see the results soon enough. Obviously, Volagi is at the forefront in this respect; they call their cycles "endurance" bikes but based on the weights and components one can easily see how a competitive road race bicycle cannot be far off on that company's horizon. Here is a quote from Barley Forman, one of the founders, re: the efficacy of disk brakes on their line:

The other obvious highlight has to be the front and rear disc brakes. To us, it was a decision that made itself: is it better? Yes, in almost every way! Road bicycles are really the only hold-out to disc brakes – every other performance form of transportation currently available has adopted disc brakes for a reason – they are better. It’s obviously about safety and control, but also about going faster, with more confidence.

Once you try discs on a long twisty downhill, we’re convinced you won’t want to go back to rim brakes. Outside of that, they’re better in the rain, work with a broken spoke, work with a dented rim, work better with carbon rims (no heat build-up), won’t roll a tire on a hot day, fits larger tires, easier to change a flat (cleaner), last longer, consistent performance, etc, etc…
 

cheetahmk7

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Sep 16, 2010
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You would think from this thread that disc brakes have no down side.

- MTB brakes can have a fair bit of initial bite. This is fine on a MTB when riding by yourself, but could easily spell disaster when riding in a nervous bunch of 100 road riders
- Discs on mountain bikes can squeel when hot
- The discs on mountain bikes often rub and there is nothing you can do about this mid race.
- The wheels on mountain bikes are really hard to replace as aligning the wheel so that the disc slides between the pads is finicky. I would hate to try swapping wheel within one lap during a crit.
 

dhk2

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doitur, here's what you replied to me yesterday, as an answer to my first question about whether you'd seen any articles or reports about the advantages of disc brakes for road race bikes:

"1. The advantages of a disk brake over any other design are so well-known that yet another article proving them again hardly seems necessary. Their current use on downhill racing bicycles and now cyclocross should be sufficient proof of their superiority on bicycles, though."

That's the answer I took as a no, that you hadn't seen any such reports. Further, that the question was so obvious (to anyone with a brain) that any testing would be a waste of time. Isn't that exactly what you meant by replying with the sentence above? Seemed it was pretty clearly written to me.

BTW, I have used disc brakes for years on road motorcycles, after riding lots of older motos with drums. On the street, never had any problems with drum brakes fading, just like I've never encountered overheating of my bicycle rim brakes. The modulation and power of hydraulic discs was better than drum brakes, even those with the double-leading edge design. The discs did have some issues with drag and squeal. Also, changing the wheel was a bit tougher and slower due to the limited clearance between the pads and the rotor. These problems would have to be solved before road-racing cyclists would adopt disc brakes. Maybe they've already been fixed on MTB disc systems, I have no experience with them.
 

tafi

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Originally Posted by doiturself .

A lot of interesting comments; really, I was interested in hearing the objections.

Disks are on the way; you don't have to use them but they're coming. Maybe it'll take a younger generation of riders not clinging to their guns and religion /img/vbsmilies/smilies/duck.gif to embrace them, but they are coming nonetheless./img/vbsmilies/smilies/biggrin.gif
Well, if they are on the way they will have to be drastically different to the discs in use now in order to be acceptable for road and road-race use.

The basic facts as they currently stand:

1) Rim brakes are already powerful enough to break road tyre adhesion. Therefore with curent tyres there is no need for more powerful brakes on road bikes.

2) In light of point (1), discs can only be useful in situations where tyre adhesion is increased to allow it. In order for that to happen, rolling resistance will have to rise as well (to do otherwise would defy the laws of nature) and i can't see any roadie being prepared to allow that.

3) As it currently stands a rider using 105/Veloce can descend with the same confidence in braking as a rider on Dura Ace/Record. This does not transfer to low-mid level disc brakes which often employ plastic caps on reservoirs (they flex and leak under pressure) and poor caliper sealing. Someone on an MTB at 40kph might be able to live with that. Descending on the road at 90+kph is a different story.

4) Rotors and disc calipers are very hard to line up. Many replies here have pointed to this being an unacceptable handicap in racing wheel changes.

5) Squealing and rubbing are always more common issues with discs than with rim brakes. Any rubbing at all robs power. Everyone knows that rotors are never completely straight and trying to ensure this is a huge extra burden on the racer or race mechanic.

6) Disc brakes will make the hubs, calipers, forks, frames and levers heavier. Radial spoke patterns will be out, further increasing the weight of wheels. Tyres are already as wide as the brake track on current wheels so we cannot expect drastic rim weight savings if the brake track isn't needed anymore.

About the only advantage I can see discs having is wet weather consistency. But then on a wet descent I can't imagine having braking power so out of line with the available grip.

Out of all of this points 2, 5 and 6 would lead most road-racers to dismiss disc brakes out of hand. No-one is going to adopt a technology which will slow them down.

As for road race mechanics, all of the above would be a significant concern when they are already pushed for time and know the ease of use, and relaibility, of the current rim brake.

If it doesn't win favour with the pros and mechs then it won't get off the ground.
 

doiturself

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Originally Posted by tafi .




Well, if they are on the way they will have to be drastically different to the discs in use now in order to be acceptable for road and road-race use.

The basic facts as they currently stand:

1) Rim brakes are already powerful enough to break road tyre adhesion. Therefore with curent tyres there is no need for more powerful brakes on road bikes.

I pointed out in an earlier post that road disks might in fact be less powerful overall than current rim brakes, but with far more consistency, excellent control, and less fade.

2) In light of point (1), discs can only be useful in situations where tyre adhesion is increased to allow it. In order for that to happen, rolling resistance will have to rise as well (to do otherwise would defy the laws of nature) and i can't see any roadie being prepared to allow that.

No, my response to point one clarifies this.

3) As it currently stands a rider using 105/Veloce can descend with the same confidence in braking as a rider on Dura Ace/Record. This does not transfer to low-mid level disc brakes which often employ plastic caps on reservoirs (they flex and leak under pressure) and poor caliper sealing. Someone on an MTB at 40kph might be able to live with that. Descending on the road at 90+kph is a different story.

As was stated earlier, certainly, the disk system design for a road racing cycle would be on a par with chassis and other component design, that is, cutting edge, light, efficient, and effective. (I wonder why one would suggest that a mid-level consumer grade braking system would be the subject of this discussion.../img/vbsmilies/smilies/eek.gif)

4) Rotors and disc calipers are very hard to line up. Many replies here have pointed to this being an unacceptable handicap in racing wheel changes.

They are not at all hard to line up, certainly not for experienced technicians. Take a wheel change on a racing motorcycle; you are talking twin disks, over 13 inches in diameter and 3/16" thick, with six-piston calipers. A skilled pit crew can make that change in just a few seconds. I myself was able to install the front wheel on my 29r mountain bike in less than ten seconds today. It took longer than that to get the skewer correctly tightened. Also, how many flats are anticipated? Dropping a chain can be worse, and with MTBs, where pinch flats are more common, wheel changes are more frequent yet MTBs all use disk brakes.

5) Squealing and rubbing are always more common issues with discs than with rim brakes. Any rubbing at all robs power. Everyone knows that rotors are never completely straight and trying to ensure this is a huge extra burden on the racer or race mechanic.

A properly designed and adjusted disk system will neither squeal nor rub. If this was true most cars, trucks, and motorcycles would be emitting such a din that any busy road would be a cacophony of howling and shrieking disks. A good disk brake system will pull the pads back just a few thousandths of an inch from the disk, resulting in virtually no drag at all.

6) Disc brakes will make the hubs, calipers, forks, frames and levers heavier. Radial spoke patterns will be out, further increasing the weight of wheels. Tyres are already as wide as the brake track on current wheels so we cannot expect drastic rim weight savings if the brake track isn't needed anymore.

This has been discussed in detail in earlier posts, but, no, the systems will be high tech, composite-based, very light, and very effective. Wheels will be lighter; take a look at the wheels on modern MTBs that use disks. The extra material that would be used to create a flat surface for pad brakes is completely gone and the wheel is angle in toward the spokes. These wheels use radials spokes with disks.

About the only advantage I can see discs having is wet weather consistency. But then on a wet descent I can't imagine having braking power so out of line with the available grip.

Why would one presume that disks have to have great amounts of power? The power will be matched to the application. Of course, disk will be much more consistent all around, wet or dry.
 

doiturself

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As far as testing the difference, I just put a set of cyclocross tires on my 2011 Camber Elite 29r MTB. Compared to any of my road bikes (steel, aluminum, and titanium) this thing can bomb down a hill and be run into a corner much, much faster -- and that is with the suspension locked, no cheating, and max pressure in the tires. There is just no comparison in terms of efficacy between the disks and chuck wagon brakes./img/vbsmilies/smilies/duck.gif

A system designed specifically for a competition road bike would be much lighter and less powerful but equally a quantum leap.

As soon as I can afford it I plan to pick up a midrange Volagi...

SRAM Rival group, and the absence of those calipers really cleans up the bike.

http://volagi.com/bikes/introducing-volagi%E2%84%A2-liscio-rival-smooth-operator-msrp-289500
 

danfoz

Well-Known Member
Apr 12, 2011
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Originally Posted by Thylacine .

Geez, much of an ego vspa? You think the 'racers' were responsible for carbon rims, STI, and ceramic bearings, oversize headtubes, oversize crank spindles? Designers and Engineers were. We make it, pro racers STFU and use it. Their job is to STFU and ride and sell the companies' ****, they are little more than rolling advertisements.
That is some deep and profound respect showcased toward the pros, I would be curious as to the company that is designing cycling products with this sentiment in mind.

Guys who win races get to dictate what they ride and their sponsors learn how to disguise equipment well or STFU like they did when Sean Kelly decided he would wait awhile before adopting clipless.

Coming from an MC background and being somewhat fearless to boot I pride myself on being a great decender (but unfortunately a miserable climber). My downhill speed is usually limited by the size of my chainring (or idiots applying too much brake). And in retort to the whole motorcycle/automobile adoption thing, until ATP is dispensed at fuel pumps along with gasoline, it's still a hard sell because after one scrubs speed entering the corner, one needs to accelerate out. Someone familiar with "burning matches" would understand this concept... a racer would. Lighter frame materials were great for aspiring polka dot jerseys, DI2 for aspiring green jerseys, clipless pedals for cyclists everywhere as they made exiting the bike, especially under the duress of an accident, a whole lot safer, and 11-speed cassettes for those of us who just can't live without the 18T. Disc brakes are great, when I'm coming down from 120mph on my Ninja, or when I'm shredding the competition playing Forza3 on my XBOX.

Disk brakes for road bikes are coming, no argument there. Those who feel they need will use, those who are enamored by gadgets for gadget's sake will use, those who are forced to adopt and aren't in a position to pushback will use. Sadly, I sense the evangelists will glean the most pleasure from the latter scenario just so it can be said "I told you so".

When this technology solves a problem that exists for me, I will adopt. Thankfully we are no longer in the middle ages and I need not fear some inquisitor pouring molten lead into my orifices to do just that.