Edge 1.45 Rims Pulsing and Question About Overheating Rims

[UncleJamsArmy]

Edge/Enve has been very cool in warrantying the second clincher rim. They're letting me switch out both rims for tubulars. I'm done with the carbon clincher experience. Also, just noticed the 1.45 clincher went up in weight to 440 grams; must be part of the beefing up process. Just as heavy as my Open Pro's.

[gumgardner]

Yah at that weight it just doesnt make sense, unless it's strictly for the bling factor

[scb]

Enve is replacing my Edge 45s under warranty. Very good folks to deal with.

[Denavelo]

I'm running Edge 45's and would love to go back to tubular deep carbon.. Carbon Clincher is convenient because of clincher tire availability, but nothing beats the ride of a good tubular wheelset.

[bluhorizan]

Edge had been very responsive to my warranty problems with their 1.45 clincher wheels. I have had a series of problems with the Edge 1.45 clincher carbon rims. First set began having pulsations with braking and was found to be warped. Edge promptly replaced the rim. This occurred again and the second wheel set was replaced. The latest version of their wheels (10/2010) were sent to me and instead of Swiss yellow stop brake pads, they now have a gray brake pad which is recommended specifically for their wheel. Took my bike out for the first time yesterday and rode my favorite 7 mile climb in Palo Alto. The wheels felt great, stiff yet comfortable and responsive. Braking also seemed improved. The descent on Page Mill road is steep and challenging with a number of switchbacks and a 8-12% grade. I'm in my 50's so I don't push the speed above 25 mph down hills and much slower in steeper sections. About a third of the way down, there are two steep switchbacks which I braked fairly hard to about 12 mph. As I exited the second switchback and started to accelerate into the next straight section, I heard a pop and then a flash of light. The next thing I recall is laying on the side of the road and several people around me. The front tire had blown out. I was taken to the local ER and had a head CT and chest x-ray. Fortunately I don't have any permanent injuries after this accident. I'm still wondering why the blow out with this brand new set of wheels with Edge developed new brake pads? I have descended this same mountain numerous times with their previous versions and wonder if there is actually less heat dissipation with these new materials. At this point I think I'm done with carbon clincher wheels despite their incredible ride characteristics. Having survived my first serious bike crash, I am thankful to be writing this post today.

[eric]

Glad to hear you wern't hurt worse.

I descent Page Mill frequently... I like that it's challenging. But I don't think I'd use carbon clinchers to go down it.

Carbon doesn't conduct heat as well as aluminum. In fact it's more of an insulator. So the heat from the brake track does not get spread through the entire rim like with an aluminum rim... it stays in the bead area, heating up the tire. If your tires started out with a high pressure like many people use, the heat can raise its pressure enough to cause it to blow out. Or cause the tire to come apart as has happened to me (the tire carcass separated from the bead).

After that I saved my carbon clinchers for races where there's not a lot of sustained braking. The steep parts of Page require enough braking to make me nervous about carbon clinchers.

[Yiannis-Super 6.]

I still don't get why you guys keep going back to carbon clinchers, the definition of insanity? keep doing the same thing and expecting a different result.

[em3]

bluhorizan...sorry to hear about your wreck. Not sure why you think your blowout was caused by rim heat and not some obstacle on the road or even a broken spoke, especially given that the blow out happened while you are accelerating after the sharp and steep turn. Also, just curious, how much do you weigh?

Hope you have a quick recovery.

EM3

[bluhorizan]

Thanks for your feedback. I just remember braking fairly hard on two successive switchbacks and starting to accelerate after the final turn, hearing a pop, feeling the front wheel turn abruptly to the left and falling. I don't recall hitting a pothole or anything on the road. I just inspected the wheel which is pictured below. The tire has partially rolled off the rim. The Bontraeger SL tube has a 12 inch linear laceration along the seam. There doesn't appear to be any damage to the rim nor broken spokes. I'm 175 pounds and 6ft tall.

A friend just sent me a link to this discussion on the differences of brake pads for carbon rims: http://glorycycles.blogspot.com/2010/11 ... e-pad.html

With the timing of the blowout, I think it was most likely due to rim overheating causing tube overinflation. My front wheel tire was inflated to 105 psi the morning of my ride. My concern is that the newly developed ENVE brake pads do not dissipate heat effectively as compared to the yellow stops that I've used extensively over the past year including last year's Markleville's Death Ride where I used Edge carbon wheels as well.

[bluhorizan]

Here is a picture of the tube

[em3]

bluehorizon, thanks for the additional explanation and the evidence (pics). From what you describe and what the evidence shoes it appears your original theory of excessive heat build up may be correct. The only additional issue I can think of that would cause a long tear/blowout in your tube is whether your tire was mounted properly and the tube was slightly pinched by the bead. However, I think that such a scenario is unlikely because you would have felt a bump while riding and I doubt it could have blown a 12 inch tear in your tube.

I bet the folks at ENVE would like to know all the details about your...hopefully they can use this sort of evidence to advance their R&D with carbon clincher technology.

EM3

[x43x]

Makes me worried about the 45 Clinchers I have coming. Would tube material have any effect on the overheating? I'm going to try latex tubes for the first time, so hopefully they work out. Maybe I just won't brake anymore.

[bluhorizan]

I definitely would use a standard weight tube. Perhaps the Bontraeger SL (superlight) tube was a factor although it feels fairly robust. Not sure if latex would be a good choice since I think it is marketed to be a minimal weight item. I'll definitely contact ENVE and let them know of this potentially catastrophic problem.

[shapeofthings]

my recently deceased edge 38 developed a pretty noticeable bulge on the the front right brake track. was using swisstop pads.
I don't think it was one ride, but a slow build-up that finally gave way to the deformation.

Edge/Enve seemed cool about replacing it, but I'm getting my wheels rebuilt to velocity a23s.
alloy makes much more sense for the type of riding I do (mostly involving climbing).

I wouldn't worry about it too much, my shop guy said the redesigned version (as mentioned earlier in the thread) hold up much better than my generation.

[morephyous]

have a set of those new enve pads, will see how they stack up against swiss stop yellow kings on a set of enve tubs