Monday, October 19, 2009

Edge Composite 68 Carbon Wheel Failure

Our protagonist, the author of a blog called "Manley Man", had recently participated in Levi Leipheimer's GrandFondo ride in California. Among the highlights of this ride are really steep descents, some of which feature blind corners.

One of these, called Meyer's Grade Road, was an 18% grade technical downhill and the Manley Man was being pretty cautious going down this road, hitting his brakes every now and then (okay, 'every now and then' maybe a huge assumption from my side). Yet, towards the bottom of the descent, he found things out the hard way. Observations were described thus :
"Toward the bottom third of this descent I felt a very bad pulsation in the front brake lever. I looked down at the front wheel to see if there was something wrong but there wasn't anything visibly bad. But it was scary to see the fork flexing back and forth under braking; it probably was oscillating at least an inch when I had the front brake applied heavily.

I got to the bottom of the descent and my teammate pulled over a few seconds later to see how I was doing. I spun the front wheel and it got stuck. It wasn't clear to me what happened. I opened the brakes up to let the wheel spin more freely. At this point I saw the issue. Initially it looked like the sidewall of my Rubino Pro had bulged out and was rubbing the break pads (yellow Swiss Stop). But to my surprise it actually was a deformity of the braking area of the rim! I had somehow managed to melt the carbon!"

Here's the deformed wheel, picture courtesy of Manley. The original specs of this clincher can be found on the product page. Because its a clincher wheel, the carbon braking track has to withstand the pressure inside the tire.

Manley Man limped through the rest of Levi's ride, being able to use what he estimated as only 10% of his total front braking power. He says that he'll be on the phone with Edge Composites having a long talk with them.

This kind of scenario has been a common topic of discussion on this blog and forums. If you'd like to get a little deeper into rim heating during braking, please see this past article. You may also notice that these kind of incidents happen not only with amateurs, but also professionals on the international stage. See this article.

Now we're all really really wondering what Edge Composites told the owner of the wheel. Will they have it replaced under warranty or pass on the blame to him with no gifts? Manley?

Do you want to discuss the specific nature of this failure? Please include your comments below.


Clincher Failure On Meyers Grade

Rim Heating During Hard Braking
Tubulars Exploding And Peeling Off
Bizarre H Plus Son Rim Failure In Japan

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1 comment:

Ken Waters said...

Hmm interesting. I was wondering under what circumstances the Edge warranty code says this can be replaced for free. If they are replacing it, they must be claiming its a known problem to occur while riding and if it does, we'll replace it. Maybe I'm late to the scene but are other wheel manufacturers now doing the same thing? Why don't they all just stop making flimsy stuff like this in the first place?