TdF - Carbon Rims in the Wet

by Scrufftie   July 11, 2014  

I wonder whether the teams in the TdF and other races ever consider alloy rims for wet days to reduce the risk of crashes. I don't have any experience of riding carbon rims but I gather that braking in the wet is less predictable and difficult to modulate.

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Well I suppose component choice and availability might be down to manufacturersponsorship requirements. Certainly if I know it's going to be wet all day then I use aluminium rims as braking is more predictable for sure.

But then I don't have to ride at 28mph and accelerate out of turns and over inclines like the pros do, just to stay in contact!

posted by 700c [587 posts]
11th July 2014 - 9:56

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My experience is that once you are used to it, braking on carbon rims in the wet is not that bad.

Actually, the pads available out there make it OK... I understand that a lot of non-Campagnolo sponsored teams find a way to fit Campag carbon brake pads to their machines as these are seen as some of the best.

The ones we use on our team are amazingly good in the wet, however they will literally last no more than 100miles in the rain.

posted by Jimmy Ray Will [317 posts]
11th July 2014 - 10:43

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Sean Kelly mentioned this yesterday or the day before - he was saying a lot of teams would go back to alu braking surfaces in the wet. I guess you just get better modulation with them? We've certainly seen a lot of crashes, so I wonder if any of them were caused by carbon rims grabbing and locking up?

posted by bashthebox [647 posts]
11th July 2014 - 12:26

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It's not long since we saw teams equipped with Nemesis handbuilts lining up for the start of classics. I guess if they really wanted to use an alloy rim, they could. The Campagnolo sponsored teams, for example, could even sport Bullets instead of Boras and no one would really notice.

posted by Nick T [834 posts]
11th July 2014 - 12:45

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bashthebox wrote:
carbon rims grabbing and locking up?

Carbon rims don't have a hope of locking up in the wet, it's the opposite problem they have. If anything you'll have less chance of skidding on a slippery surface with carbon rims thanks to the loss of braking.

posted by Nick T [834 posts]
11th July 2014 - 12:48

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That's not my experience... typically carbon brakes in the wet have very little power, but then the rims start to heat, the surface dries and you get a very rapid change from no brakes to very sharp braking.

The quicker the surface heats and dries the less pronounced this transition is.

posted by Jimmy Ray Will [317 posts]
11th July 2014 - 13:14

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I can't say that I've had that happen to me, but I've only used carbon tubs. Is that on clincher or tub rims?

posted by Nick T [834 posts]
11th July 2014 - 13:27

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Nick T wrote:
bashthebox wrote:
carbon rims grabbing and locking up?

Carbon rims don't have a hope of locking up in the wet, it's the opposite problem they have. If anything you'll have less chance of skidding on a slippery surface with carbon rims thanks to the loss of braking.

Not true.

Carbon brakes significantly, significantly, better in the dry than alloy, and probably around the same in the wet. It's one big difference in performance that catches riders out.

The other thing is modulation. Carbon rims can lock up in the wet just like in the dry, but the initial bite is extremely feeble, than as the pads dry the rim they begin to bite. Hard.

Because of this it's easy to overcook it braking by gripping the brakes too hardwhen riding with carbon. The rapid change in braking strength causes you to lose traction in your tire. If it's the front tire on a wet, greasy surface, then it's pretty likely you will crash.

posted by Gordy748 [98 posts]
11th July 2014 - 22:35

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Gordy748 wrote:

Carbon brakes significantly, significantly, better in the dry than alloy, and probably around the same in the wet.

Both my carbon and alloy wheelsets would beg to differ on this.

posted by Nick T [834 posts]
12th July 2014 - 5:35

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At tdf speeds I'm sure carbon rims perform differently than at amateur speeds.

posted by Beaufort [183 posts]
12th July 2014 - 6:59

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