Warning: Swisstop Yellow Fail

[twizzle]

Carbon fibre composite components don't accept/dissipate heat, which is why the pads have to be 'melt proof'. Just like the brakes on a car, you can't "ride the brakes", you have to get the pads off the rim to let them cool down.

Just of out interest... how long should people expect a carbon rim to last? My alloy training rim lasted less than two years before the sidewall split, carbon rims wear under braking as well - should people expect them to last forever? Perhaps ASBB's front rim was too thin to handle the heat?

Edit: damn you, auto-correct!

[Nobody]

...you also need to think about how you break when using carbon.

Yes I've often thought about this. That's why I use high spoke count alloy wheels.

[herzog]

Bring on hydros for road. It's 2012.

[Nobody]

Just of out interest... how long should people [expect] a carbon rim to last?

I don't think this enters into the equation when most people consider carbon wheels.

My alloy training rim lasted less than two years before the sidewall split...

You'd benefit more than most from a front disc conversions in durability and safety.

...carbon rims wear under braking as well - should people expect them to last forever? Perhaps ASBB's front rim was too thin to handle the heat?

Good point. I doubt any manufacturers of carbon brake track wheels would want to release data on the average braking life of their wheels. Might put a dent in their sales.

[pawnii]

The life of carbon rims would be determined by the quality of the resin and moulding process more than the carbon itself.
yes/no?

[aeroslave]

Bring on hydros for road. It's 2012.

+100

[notwal]

Bring on hydros for road. It's 2012.

+100

I take it you mean discs.
I think that discs, although they may provide an effective solution, are a work around. Rim callipers remain the most mechanically elegant solution to braking for a road bike. Rim braking just has to be improved. The problems of heat dissipation and wet rims should be and are being tackled by manufacturers.

Easton make a song and dance about the heat resistance of the resin in their composites. I don't know how good it is but I have no doubt good solutions will emerge. The aircraft industry depends on the stuff.

[Nobody]

Bring on hydros for road. It's 2012.

+100

I take it you mean discs.
I think that discs, although they may provide an effective solution, are a work around. Rim callipers remain the most mechanically elegant solution to braking for a road bike. Rim braking just has to be improved. The problems of heat dissipation and wet rims should be and are being tackled by manufacturers.

The manufacturers are tackling the problems by releasing disc brakes soon for road use. I think the bicycle is the last (light) vehicle I know of that uses rim brakes. If there was a better solution than discs, it should have been applied in some other form of light vehicle by now.

I still find rim brakes useful as rear wheel brakes where less braking power is required and braking performance is less critical.

[Mulger bill]

Problem with discs on a roadie is that trendy radial spoking is a no no

[jules21]

Problem with discs on a roadie is that trendy radial spoking is a no no

shaun, that's not really that big a problem - if you're willing to pay the weight penalty of disc brakes, then what's an extra 10 spokes?

i don't see discs taking off on road bikes. but then, it's dangerous making those sorts of predictions

[sumgy]

Did everyone else miss the part where he has used these same carbon rims for 4 years both racing and training?
I would blame the fact that you are using 4 year old heavily used carbon rims on the failure before I blamed the well respected Swiss Stop pads.

[rkelsen]

i don't see discs taking off on road bikes.

Agreed. What's the point of spending megabucks on lightweight carbon rims, and then handicapping them with discs?

The issue discussed in this thread could be avoided by using rims with an alloy braking surface. Of course, there would be a weight penalty... Measurable in tens of grams, not the (several) hundreds of grams discs would add.

but then, it's dangerous making those sorts of predictions

It's also dangerous to say stuff like this around here.

[jcjordan]

Carbon fibre composite components don't accept/dissipate heat, which is why the pads have to be 'melt proof'. Just like the brakes on a car, you can't "ride the brakes", you have to get the pads off the rim to let them cool down.

Just of out interest... how long should people expect a carbon rim to last? My alloy training rim lasted less than two years before the sidewall split, carbon rims wear under braking as well - should people expect them to last forever? Perhaps ASBB's front rim was too thin to handle the heat?

Edit: damn you, auto-correct!

My Bouwmeester White Dot (the orginal version) 38mm clinchers are now 3 years old and still going strong. They have alot of km's on them and they still have their integrity around the breaking zone. They have started to yellow there from nearly a constant use of yellow swiss stops but otherwise no decernable wear.

[Nobody]

i don't see discs taking off on road bikes.

Agreed. What's the point of spending megabucks on lightweight carbon rims, and then handicapping them with discs?

The issue discussed in this thread could be avoided by using rims with an alloy braking surface. Of course, there would be a weight penalty... Measurable in tens of grams, not the (several) hundreds of grams discs would add.

but then, it's dangerous making those sorts of predictions

It's also dangerous to say stuff like this around here.

I suspect the future will prove you wrong.



http://www.canyon.com/_en/technology/project68.html
viewtopic.php?f=34&t=31034&start=600

[rkelsen]

http://www.canyon.com/_en/technology/project68.html

That'd be "Project 5.8" with rim brakes.

[DaveOZ]

Agree. After running my CX bike with discs for over a year now I would love to have disc on all my bikes. I think the weight would come down given that wheels could be designed without the need for a braking surface.

[Nobody]

http://www.canyon.com/_en/technology/project68.html

That'd be "Project 5.8" with rim brakes.

You can't say that for sure and I highly doubt it. As DaveOZ said above, once the braking surface and extra associated bulk is removed from the rims, the wheels should be lighter where it counts, on the outer edge. Also since UCI has still got the current weight limit, it easily leaves an opportunity for discs to be added without adding weight.

[jules21]

Also since UCI has still got the current weight limit, it easily leaves an opportunity for discs to be added without adding weight.

i had forgotten about this. i think discs can work in this context - but the attraction is likely to be less for riders of non-UCI weight weenie bikes. i just don't find rim brakes to be that important - how often do you really need max. performance from them?

[Nobody]

i just don't find rim brakes to be that important - how often do you really need max. performance from them?

Remember the Goodyear ad on TV? "If it only saves you once a year...". To me, it's not about averages or how often, it's about that one time you're caught out in the rain and you have a car pull out in front of you while on a decent. For the sake of a few hundred dollars and some weight, I'll be less likely to need to reflect on the worst case scenario while lying in a hospital bed.

[sumgy]

i just don't find rim brakes to be that important - how often do you really need max. performance from them?

Remember the Goodyear ad on TV? "If it only saves you once a year...". To me, it's not about averages or how often, it's about that one time you're caught out in the rain and you have a car pull out in front of you while on a decent. For the sake of a few hundred dollars and some weight, I'll be less likely to need to reflect on the worst case scenario while lying in a hospital bed.

Long term hydro user on my MTB's but IMO the additional braking power that these will bring to a roadie will be balanced out by the increased lack of grip that a road tyre has compared to an MTB tyre, leading to possible increased sliding and stopping distance.

Only crash I ever had in the rain on my roadie was due to a slide around a sharp bend.

[DaveOZ]

Can't blame the brakes for lack of control by the user. I find discs much easier to modulate than rims.

[sumgy]

Can't blame the brakes for lack of control by the user. I find discs much easier to modulate than rims.

So you have used disc brakes with 23mm tyres?
I dont find either easier or harder.

[DaveOZ]

Can't blame the brakes for lack of control by the user. I find discs much easier to modulate than rims.

So you have used disc brakes with 23mm tyres?
I dont find either easier or harder.

Yes, I have discs on my commuter.

[Nobody]

Long term hydro user on my MTB's but IMO the additional braking power that these will bring to a roadie will be balanced out by the increased lack of grip that a road tyre has compared to an MTB tyre, leading to possible increased sliding and stopping distance.

Only crash I ever had in the rain on my roadie was due to a slide around a sharp bend.

I've had a front disc (BB7, 185mm) on my road/CX bike since about March 2010. Seems fine to me. Never felt overpowered. Never crashed a road bike yet.

[sumgy]

Long term hydro user on my MTB's but IMO the additional braking power that these will bring to a roadie will be balanced out by the increased lack of grip that a road tyre has compared to an MTB tyre, leading to possible increased sliding and stopping distance.

Only crash I ever had in the rain on my roadie was due to a slide around a sharp bend.

I've had a front disc (BB7, 185mm) on my road/CX bike since about March 2010. Seems fine to me. Never felt overpowered. Never crashed a road bike yet.

mmmkay.