Are all carbon clin...
 

[Closed] Are all carbon clinchers for rim brakes affected by heat?

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Had a couple of carbon clincher rims replaced under warranty due to uneven braking/ grabbing after only a little use.

Can't complain at the warranty provision but it seems the braking went uneven not even through any excessive braking or heat build up.

Is this uneveness inevitable after a period of time with all carbon clinchers? Does the gradual heat effect of braking eventually make such rims go uneven?

I want another set of clinchers but don't want to splash out on a set, cheap or expensive if they're going to start grabbing after hardly any riding.

Does anyone else have such experience?


 
Posted : 21/09/2015 12:24 pm
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due to uneven braking/ grabbing

I genuinely thought "they all do that, mister"?


 
Posted : 21/09/2015 12:35 pm
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No, when I first got them, the braking was smooth through the whole wheel revolution.

After a few rides, braking on the rear rim was like someone tugged at the wheel once per revolution. A real grab then let go kind of sensation.


 
Posted : 21/09/2015 12:44 pm
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The first thing you should do is tell us what brand you bought.


 
Posted : 21/09/2015 1:03 pm
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No, I'm not doing that, as I'm not grumbling about the product brand, just want to know about carbon wheels in general.

Would I get this problem say on Zipp?


 
Posted : 21/09/2015 2:20 pm
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I have been using a set of Nextie rims on my road bike since the Spring and I haven't had anything like you describe. I did however go for the basalt braking surface on them.


 
Posted : 21/09/2015 2:34 pm
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Would I get this problem say on Zipp?

Dunno, for all we know you're already talking about Zipp's...


 
Posted : 21/09/2015 2:42 pm
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Would I get this problem say on Zipp?

You could, yes. If you drag your brakes a lot and get the rim hot enough then they'll go wobbly and grabby. No carbon rim is immune from this, but it's a pretty extreme use case.


 
Posted : 21/09/2015 3:02 pm
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Ok, well this happened not in an extreme use case and definitely no dragging of brakes.

Didn't want to waste my money on another set only to find its a normal 'feature'


 
Posted : 21/09/2015 5:09 pm
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FWIW Mavic replaced* >80 individual carbon clinchers at the Marmotte this year that had failed due to heat build up, shocking..

edit *as in supplied a spare until a rider had finished


 
Posted : 21/09/2015 5:26 pm
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There was a thread on WW about Enves doing it in some US sportive too, but they were actually 'melting' to the point of not fitting in the frame.


 
Posted : 21/09/2015 5:36 pm
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I've done about 20,000km on HED carbon wheels over the last few years including La Marmotte this year and lots of other alpine trips with no problem. I've used both standard and carbon pads.

My wheels are tubs, but I can't see that would make any difference to this question.

I'd be looking at another brand if I were you.


 
Posted : 21/09/2015 5:40 pm
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^ Tubs handle the pressure increase without issue, which is where I believe some carbon clinchers fail


 
Posted : 21/09/2015 5:48 pm
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tubs, but I can't see that would make any difference to this question.

A tub rim is essentially a square in profile, and rather stronger than a u-shaped clincher, where the sidewalls can distort to be non-parallel rather more easily.


 
Posted : 21/09/2015 5:50 pm
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Think about the explodey style pressure exerted on a clincher via the tube and tyre opposed to a tub that's just glued on. If you heat up "plastic" until it gets squishy it's going to get messy.


 
Posted : 21/09/2015 5:53 pm
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Aren't HED's alu with a carbon fairing? I thought they'd only very recently released full carbon?


 
Posted : 21/09/2015 5:54 pm
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I've put nearly 2 years onto a set of farsports 38mm clinchers .. Been using Swiss stop black prince pads on them and they have been faultless ๐Ÿ™‚


 
Posted : 21/09/2015 5:57 pm
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I've known Mav previous version of the M40C's I use fade yes, but then that was hacking over the Dolomites in 11' and yes the rims did get hot and the coating came off the face, Mav replaced them obi's but I have known it happen. As is I'm now on set 4 (I change them every season since coming from Lightweights) and never had a problem since.

Would I use Zipps'? No.
Enve? No
Lightweights? never ever again.

I'm sticking with Mav.


 
Posted : 21/09/2015 6:02 pm
 tlr
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tubs, but I can't see that would make any difference to this question.
A tub rim is essentially a square in profile, and rather stronger than a u-shaped clincher, where the sidewalls can distort to be non-parallel rather more easily.

Fair enough.


Aren't HED's alu with a carbon fairing? I thought they'd only very recently released full carbon?

Jets are Alu with a fairing, the Stingers are all carbon tubs.


 
Posted : 21/09/2015 6:08 pm
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I've been riding Corima wheels on the road the last few months. I thought it was impossible for them to get hot because I can't squeeze the levers hard enough to get any braking friction at all.

It's a borrowed bike with Campag Record brakes and at the first T junction the lack of braking compared to my XT discs came as a bit of a surprise.


 
Posted : 21/09/2015 6:09 pm
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#swisstops..


 
Posted : 21/09/2015 6:11 pm
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Sounds like its no more likely to happen on cheap carbon rims as it is for expensive ones then.

This happened just from local riding, not the Alps or even the Lakes say.

I was going to try some Farsports or similar.

Why not Lightweights Bikebouy?


 
Posted : 21/09/2015 6:25 pm
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I'd have sufficient confidence in FarSports to buy some. Indeed I have. My 38mm 2016 rims turned up on Saturday.


 
Posted : 21/09/2015 6:33 pm
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^^ did you buy direct or from the Aliexpress store?


 
Posted : 21/09/2015 6:35 pm