So, I’m a 182lb rider who has managed to crack two carbon tubular rims this season: an older Zip 404 non-dimpled rim (2004?), and an older HED Stinger rim (year uncertain, has a nearly identical toroidal shape to the older 404). The cracks both happened in shorter races on city streets with lots of potholes, while I was in the pack. I suspect that these wheel-cracking encounters would have simply caused a pinch flat on clinchers, putting me out of contention.
As wheel replacements are starting to cost more than I’d like, I am exploring my options. I do have a pair of 404 clincher wheels that are just as fast, except for being about 350 grams heavier. I am comfortable gluing my own tubulars, so the clincher/tubular point is moot. I just want to be able to finish races without destroying my equipment.
What experiences have you had with carbon rim failure? Are the newer 2009 rims any more reliable? Should I just stick with clinchers or box-section tubulars? Have any of you used Calfee’s (or someone else’s) carbon repair service for a carbon rim? Should I simply save the nice carbon wheels for longer road races, using something more durable in crits and circuit races? Given that Zipp markets variants of the new 303 and 404 rims as cyclocross wheels, I suspect that I’ll have better luck with the newer rims. At the same time, I don’t want to pay for yet another cracked rim!
Please let me know what you think.
Where did it crack. Usually carbon rims crack/stretch at the nipple holes from the force of the spoke pulling it.
I’m finding myself in much the same position that you describe. After researching my options on what to do with a damaged carbon rim I’m returning to using an aluminum box rim with wheelcover for my tri rides. After considering durability, reliability and serviceability I couldn’t justify the $ for replacement rims. For the record, I race at 190lbs.
Although I don’t believe that my experience with the durability of carbon rims is typical, I don’t want to continue with what I now see as increased risk every time I use my race wheels. My last rear clincher rim got me through two IM’s and two IM/2 before showing a crack at a spoke hole.
Certainly there is risk in everything we do but I’ve made the decision for myself that exposing high price wheels to the common hazards that we all encounter when riding isn’t worth it.
For those who haven’t reached this point yet and whose experiences differ, keep an eye on the classifieds for a damaged carbon wheel going up for sale.
Rob
Please allow me to clarify: the rims have cracked at or across the tire bed or at the brake track, as a direct result of hitting a pothole or some other object in the road. My tires were inflated to 120-130psi. I did my best to unweight, but sometimes there is little you can do in a race.
FWIW the newer version of the Zipp rims are supposed to be a lot better at impact resistance than the old ones. They basicly found a way to make the Pave version of the rim without adding the extra weight of the additional carbon layer at the tire bed. That is all well and good, and I know for a fact that it is not jsut marketing hype, but the bottom line is that guys like us that are over 180lbs are going to bang the occational rim. If it were a clincher you would certainly damage the outer portion of the rim and maybe the brake track. Sharp cornered potholes @ 20mph are going to destroy anything being ridden by a big guy.
The real question is replacement cost, and if you are good with $400 rebuilds or $100 rebuilds.
Also you could try running a fatter tire like 25c to help carry the weight at the rear.
At 185, I’m in that weight range. But it’s much better than the 240 I was 11 years ago and the 210 I was just a couple of years ago. I have ridden the older Zipps with the black Edco hubs, 1st generation 202s, 808s, and have a few rides in on Reynolds KoMs. Never cracked a carbon rim. And I’ve hit a few potholes on all but the Reynolds.
The funny part is that I’ve cracked the rear rims on both Ksyrium SLs and ESs! The ESs when I weighed 180 – which now appears to be my summer weight.
Go figure…