Disco Breaks.

craprider

This has probably come up before, but with teams having to add weight to their bikes to meet UCI standards why don't pros ride discs?
The Breaking advantage both descending and in the wet make it a no brainer to me?

iainf72

craprider wrote:

This has probably come up before, but with teams having to add weight to their bikes to meet UCI standards why don't pros ride discs?
The Breaking advantage both descending and in the wet make it a no brainer to me?

Against the rules.

craprider

so increasing safety is against the rules?
i knew the UCI were stupid but that takes the biscuits.

nweststeyn

You want the riders to stop every 30 minutes and dance?

rozzer32

craprider wrote:

so increasing safety is against the rules?
i knew the UCI were stupid but that takes the biscuits.

Apart from when you have a crash in the peloton and have disc brakes acting like circular saw.

nweststeyn

nicklouse

nweststeyn wrote:

http://www.dailydiggers.com/2008/05/disco-breaks.html

cougie

craprider wrote:

so increasing safety is against the rules?
i knew the UCI were stupid but that takes the biscuits.

I think the normal brakes are safer - and you'd need everyone to be on discs or none of them. If braking is improved in say half the peleton - the other half would just pile into them ? And its usually the amount of rubber on the road thats the limiting factor ?

craprider

But then you have the arguments that you should only have carbon or metal rims due to the difference in breaking?
its just inconsistent. as usual.

greasedscotsman

craprider wrote:

But then you have the arguments that you should only have carbon or metal rims due to the difference in breaking?
its just inconsistent. as usual.

Breaking?

nweststeyn

greasedscotsman wrote:

craprider wrote:

But then you have the arguments that you should only have carbon or metal rims due to the difference in breaking?
its just inconsistent. as usual.

Breaking?

Metal rims tend to fatigue, whereas carbon can break suddenly and catastrophically...

I'm assuming that's what craprider meant

ddraver

What cougie says is correct, I ve never considered the point about rims though, fair point!

Genuinely i think it's because they re traditionalists and they don't want bikes to look different. Another problem is that the current halfway house braking systems are not so good yet because there is no benefit to putting the R&D money into making the brakes (SRAM Red excepted) or the frames. It's a vicious circle basically...

It's even more of a shame because i reckon 99% of us normos would be better off with discs...

craprider

i cant speel for siht today :P

I did mean the difference in carbon and metal surfaces for BRAKING yes.

andyp

IanLD

I still think the additional time to relocate a wheel with disc brakes (especially the rear) may be a factor that prevents pro use. The Formula brakes on the new Colnago with fully hydraulic levers look great. I use Formula on my hybrid and my mountain bike, but find it a real pain sometimes when the disc hits the pads when putting a wheel back in.

I also find the feel of my Campag Centaur brakes on the road bike to be nicer. The power of the discs may not be there, but there is still plenty to lock up a wheel.

If the marketing guys decide that is the way we are going, it will happen, but I'll reserve judgement until I've tried it and also seen how the pros cope.

clanton

Number of reasons why disc brakes are not going to hit the pro riad scene for a while:

The technology needs work - small light disc brakes as per what you'd want on a road brake are prone to overheating and brake fade with potentially catastophic results on long descents.

There would be issues with the changeover - how do you cope with neutral support vehicles with some caliper brakes/some disc brakes?

Safety issues as above re crashes - heated discs can burn.

The limiting factor for braking is the grip you can get on the road - not the braking strength of the brakes themselves usually. So where is the need for them?

Changing wheels is slower with disc brakes - you need to seat the dic inside the caliper. Unless the frame spacing and hub spacing are exact throughout the peleton and every caliper set up perfectly you will have continual niggles with this - leading to potentialy disastrously slow wheel changes/dragging disc brakes etc.

rick_chasey

It'll happen eventually.

They used to put badges on the back of Jags in the '60s telling the driver behind that it had really good brakes.

ddraver

Answers...

clanton wrote:

Number of reasons why disc brakes are not going to hit the pro riad scene for a while:

The technology needs work - small light disc brakes as per what you'd want on a road brake are prone to overheating and brake fade with potentially catastophic results on long descents.

Mostly true about size and weight but the overheating thing is not a real problem. Certainly no more so than brake fade with calipers. Most of these stories have come from people who have tried a half assed halfway house approach and then dragged their brakes all the way down the hill

There would be issues with the changeover - how do you cope with neutral support vehicles with some caliper brakes/some disc brakes?

True enough at the moment but I reckon a standard will appear soon enough

Safety issues as above re crashes - heated discs can burn.

As can heated rims

The limiting factor for braking is the grip you can get on the road - not the braking strength of the brakes themselves usually. So where is the need for them?

Modulation, control and decreased power needed at the fingers. I can one finger brake on my MTB down tracks steeper than any road (and also down roads, but where's the fun in going down a road ). Even with my calipers in supor tip top condition I can't do that. Plus disks work consistently in the wet/dry/mud. Think Spring classics. By removing the brake surface from the rims you could reduce the weight of the rim, increase the aerodynamic benefits (if that's your bag) and make it stronger

Changing wheels is slower with disc brakes - you need to seat the dic inside the caliper. Unless the frame spacing and hub spacing are exact throughout the peloton and every caliper set up perfectly you will have continual niggles with this - leading to potentialy disastrously slow wheel changes/dragging disc brakes etc.

True....but then this is a problem that does nt exist in MTBing. If you puncture, you either squirt a load of sealant and CO2 in and pray or your race is over and 5 seconds extra is irrelevant. More work is needed, but it's not an insurmountable problem. A certain amount of self adjust is possible with the calipers as they have to take into account pad wear, bent disks etc

Outsider art by Loan

Ignoring the other issues surrounding disc brakes on road bikes, I reckon letting riders brake harder and more suddenly would create more problems than it would solve.

mfin

Discs would burn you far more than rims if you touched one after the same amount of braking. Its simple physics, the total braking forces are happening over a much smaller surface area and only come out as heat and sound.

For anyone who's never touched a disc after doing some heavy braking DONT try it, the metal can get glowing hot, it will burn you and you will lose your fingerprints. Spray water from a bottle on your mate's mountain bike disc brake after he's come down a descent with a minute or so's braking and watch him jump up through the resulting steam like a genie.

Fact is, if you crashed in a pile up and brakes were hot it would be like pressing a knife that's been heated over a gas cooker against your skin.

I reckon they should allow them.

nweststeyn

I've been burnt by a disc on my downhill bike a few years ago... I could descend with my hands on the brakes of my road bike for 10 minutes and it still wouldn't be that hot - it were 'orrid!

But thats an aside to the other, more major, issues anyway...

AchillesLeftKnee

I would have thought the problem would be to do with the size (aeroness and weight) of discs you'd need to be able to cope safely with the speeds and durations of some road descents. Proper downhill MTB brakes are tonking great beasts, and I would have thought anything that's likely to be required to descend an Alp at race pace would require something equally massive and obtrusive.

Paul 8v

It will happen but not in its current form and not for a few years.

As for Disco breaks, stopping every few hours and throwing some shapes sounds like a great way to stretch out ;-)

No_Ta_Doctor

"Peter Sagan took the lead in the Sony Music Discobreak Jersey after beating Thomas Voeckler in the intermediate Danceoff. In the post race press conference Sagan shrugged off a series of questions from Paul Kimmage regarding the use of disco-biscuits in the peloton by opening his arms wide and saying 'I love you. Can you feel the force? Can you feel it? I love you all'"

DeadCalm

No tA Doctor wrote:

"Peter Sagan took the lead in the Sony Music Discobreak Jersey after beating Thomas Voeckler in the intermediate Danceoff. In the post race press conference Sagan shrugged off a series of questions from Paul Kimmage regarding the use of disco-biscuits in the peloton by opening his arms wide and saying 'I love you. Can you feel the force? Can you feel it? I love you all'"

craprider

ddraver

I wanna see Sagan recreate that on the bike over the next finish line...

angrynortherner

Wouldn't you need to beef up the fork legs and rear stay as well? Current front brakes are mounted on the crown (one of the strongest areas), discs would be applying all the force at the bottom of the fork so would need to be beefed up to cope.

Also from an aero perspective the current solution is largely hidden by the fork crown, some element of the disc and calliper would always be stuck out in the wind.

Discs are great for CX/MTB's, I've never ever thought my road brakes (6700 Ultegra) were weak - the canti's on my CX bike are by far the worst brakes I've ever had.

craprider

no idea, but it wouldn't be too hard.

deejay

Rick Chasey wrote:

They used to put badges on the back of Jags in the '60s telling the driver behind that it had really good brakes.

"Off Topic" That brings a smile to my face.
Small company (just started in the 60's) gave me an Austin-Mini and the fastest it would run at was 87 mph with a good tail wind.
With a mile to go to the end of Motorway M45 an E type Jag overtook me doing at least a Ton and as I watched him I thought he should be braking before the roundabout at the end.
He did eventually and skidded straight into the side of an 8 wheel truck that was going around the R/B.
As I passed by I noted the Jag was starting to fold like an envelope.
I never saw one of those badges though.

Vino'sGhost

mfin wrote:

Fact is, if you crashed in a pile up and brakes were hot it would be like pressing a knife that's been heated over a gas cooker against your skin.

I reckon they should allow them.