Disc Brakes for Pro Peloton

ciderman_100 wrote:

I think the main thing is that we need a definitive rear spacing measurement and disc diameter otherwise you'll be locked to certain makers due to differing standard just look at the amount of bb sizes

Why do we need those things standardised? We are locked into a manufacturer in so many other ways already. Have you got Shimano gears? If so, you are locked into their rear mech, shiters and brakes already. Same goes for SRAM and Campag. You pick your component manufacturer and go with their offerings.

PaulBox wrote:

If they are approved for the pro's we'll all be riding them in a few years. This is the reason I currently can't pull the trigger on a new bike. I'd happily buy another with normal brakes, but will that limit my options on replacement wheels in three years time?

Try buying a rim brake wheel for a mtb these days, yes you can, but not any of the best models.

if you can still get square tapered BBs I am sure you will be able to get rimmed brake parts in three years time.

Shep73 wrote:

You can also go past the braking power/limits of discs, anyone who may have ridden down the radio mast climb near Marlborough at high speed will know that discs have their limits.

Sounds like a descent you'd only do very slowly on rim brakes... just saying.

And Shimano brakes are very easy to bleed, though never had much luck with SRAM / Avid ones...

movingtarget wrote:

I must say in my personal experience, I have mech disc brakes on my winter (cyclocross) bike and I love them and hate them. It's very wet in Portland and on rainy days having the added reliable stopping power in traffic and on descents is the main reason why I bought a disc-equipped bike. That said, I really feel the drag on them in crosswinds where at times I'm fighting being pushed into traffic and there is definitely a weight penalty on climbs and group rides. Would I buy them again? Probably since it's a winter bike but not for the summer road bike.

Since the pros are doing alpine descents, I would think that the crosswind aerodynamics would have a significant impact.

Are you sure it's just the discs having this crosswind effect and not any of the significantly larger factors at play- like you or what you're wearing or what you had for breakfast?

surly_by_name wrote:

my advice would be to avoid going too long on wheelsets 'cause in 3 years time you will struggle to buy a frame without 135mm OLD rear end/disc tabs.

not sure I agree - and in any case that assumes people view bike frames as disposable items with a short life. I fully intend to still be on my ti frame in 3 years time and won't be 'upgrading' it simply because the new things is a new brake system or bottom bracket standard, or whatever

drmatthewhardy wrote:

All the pro-disc people talk as if bikes still had drum brakes like cars did before disc brakes.

No they don't.

Welsh boy wrote:

ciderman_100 wrote:

I think the main thing is that we need a definitive rear spacing measurement and disc diameter otherwise you'll be locked to certain makers due to differing standard just look at the amount of bb sizes

Why do we need those things standardised? We are locked into a manufacturer in so many other ways already. Have you got Shimano gears? If so, you are locked into their rear mech, shiters and brakes already. Same goes for SRAM and Campag. You pick your component manufacturer and go with their offerings.

Yea but all axle spacing are the same on all those groupsets you've listed.All the groupsets fit any/all frames for now hence the need for standard sizings so all frames pair with new disc brake groupsets

jacknorell wrote:

Shep73 wrote:

You can also go past the braking power/limits of discs, anyone who may have ridden down the radio mast climb near Marlborough at high speed will know that discs have their limits.

Sounds like a descent you'd only do very slowly on rim brakes... just saying.

And Shimano brakes are very easy to bleed, though never had much luck with SRAM / Avid ones...

But the Pro's hit them at speed, and the point I'm getting at is complacency in riders who may think they have more power than they actually have on fast descents. Shimano are better for bleeding apparently but you have to be patient with them. Some people just don't get on with it so it's a job for their LBS.

LOL, well I am more likely to eat oatmeal in the winter ....

But seriously, there are even wind tunnel tests showing that ~20 degree crosswinds produce significant and consistent drag on disc vs rim braked bikes. The rotor's a small surface area but when you have 20+ mph swirling gusts or microshears which happen pretty frequently where I ride and in alpine conditions it'll be noticeable.

http://velonews.competitor.com/2014/12/bikes-and-tech/discs-drag-wind-tu...

700c wrote:

surly_by_name wrote:

my advice would be to avoid going too long on wheelsets 'cause in 3 years time you will struggle to buy a frame without 135mm OLD rear end/disc tabs.

not sure I agree - and in any case that assumes people view bike frames as disposable items with a short life. I fully intend to still be on my ti frame in 3 years time and won't be 'upgrading' it simply because the new things is a new brake system or bottom bracket standard, or whatever

Have a look at the MTB market for what may be about to happen. You can get 26" kit, however considering this is the first year of 650's from the major manufacturers it is shocking how quickly the good stuff is being dropped. Lots of stuff is only in 650 or 29.

I was looking at Chainreaction the other day for a 9spd rear mech for the mtb, and again not much choice, XT or deore i think. I seem to remember that it was RockShox policy to manufacture spares for nothing over three years. Obviously parts that were common could be used but anything model specific and you started to have problems.

So yes you might want to keep your bike a while but the manufacturers certainly won't be providing the spares to keep it going any longer than they deem necessary.

Just to be clear spares will be available, just don't expect the good stuff.

Shep73 wrote:

jacknorell wrote:

Shep73 wrote:

You can also go past the braking power/limits of discs, anyone who may have ridden down the radio mast climb near Marlborough at high speed will know that discs have their limits.

Sounds like a descent you'd only do very slowly on rim brakes... just saying.

And Shimano brakes are very easy to bleed, though never had much luck with SRAM / Avid ones...

But the Pro's hit them at speed, and the point I'm getting at is complacency in riders who may think they have more power than they actually have on fast descents. Shimano are better for bleeding apparently but you have to be patient with them. Some people just don't get on with it so it's a job for their LBS.

Apart from being a mistake you'd only do once...

Who in their right mind would slam on the brakes at max velocity rather than learn where the limit is beforehand?

Power is not an issue, grip runs out long before, btw.

Quote:

Who in their right mind would slam on the brakes at max velocity rather than learn where the limit is beforehand?

Power is not an issue, grip runs out long before, btw.

Just like the born again bikers, who make up the highest death rate for motorcycling, not realising the power available at the lower CC end, Mamils are the equivalent, have not ridden a bike for 25yrs, and only have the previous tech to base their knowledge on. I have seen more mamils at the side of the road bleeding than I have ever done teens/twenties etc. lighter faster more powerful braking, just the same as motorcycles.
I think personally there should be a minimum skill level and fitness test for riding on the road. 10mph is not safe on any road with cars on. IMO.... I will say that again....IMO. Not yours not anyone else's, mine.

benevans wrote:

Has anyone had there finger caught in a disc brake rotor? with mass pileups rather frequent in road racing, is this something that should concern the UCI?

Has anyone been bitten by a sharp chainring, has anyone caught their finger in rotating spokes, has anyone hit their face/head on the floor? All considerations in bunch crashes so I dont think this is a real worry for the UCI.

Welsh boy wrote:

benevans wrote:

Has anyone had there finger caught in a disc brake rotor? with mass pileups rather frequent in road racing, is this something that should concern the UCI?

Has anyone been bitten by a sharp chainring, has anyone caught their finger in rotating spokes, has anyone hit their face/head on the floor? All considerations in bunch crashes so I dont think this is a real worry for the UCI.

And the UCI banned spinergy wheels and spinaci's because of safety questions. (at least that was the given reason)

And you could say, why add more dangerous things to a bike? isn't the risk of chainring gouges bad enough, why add the risk of burns into the mix?