Cracked carbon around BB shell. Salvageable? Can I ride it?

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bikerjulio
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Joined: Fri Dec 11, 2009 10:38 pm
Location: Welland, Ontario

by bikerjulio

If I thought that a failure there would be catastrophic, then I'd be agreeing with the "don't race" guys.

But I don't.

I had a very similar failure, that was not even that noticeable when riding. I noticed it off the bike by being able to wiggle the crank a little, but that was it.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

by Weenie


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stella-azzurra
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Location: New York

by stella-azzurra

For it to be catastrophic you would need both sides of the bb shell to fail a the same time.
Worst thing would be to render this frame unrepairable.
If you can wiggle the crank now it will only get worse.

A more catastrophic event would be for the chain to come off suddenly which would cause you to crash if you were accelerating suddenly. This could be caused by the BB shifting off it's center.

On second thought this could be catastrophic :lol: :lol: :lol:
I wouldn't ride it if you were seriously racing.
A ride in the park maybe.
I never took drugs to improve my performance at any time. I will be willing to stick my finger into a polygraph test if anyone with big media pull wants to take issue. If you buy a signed poster now it will not be tarnished later. --Graeme Obree

mrfish
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Location: Near Horgen, Switzerland

by mrfish

Injecting epoxy as the armchair enthusiasts suggest won't work. Epoxy alone does not put any carbon across the crack, then an external patch only links the carbon on one layer, so the 10 layers of carbon below which have been carefully placed according to finite element analysis and a detailed layup schedule are doing nothing. Then the repair process suggested does not compact the repair area. Solving these problems requires rebuilding the bb lug and therefore your expert is right in suggesting this is not cost effective.

Racing the frame is a bad idea. Even if there's only a 1/100,000 chance that the bb falls out and then causes someone else to crash, you will have been negligent and so not covered by accident or legal insurance. The consequences of being sued by a middle-aged guy (e.g. partner in a law firm) for loss of earnings, hospital bills etc. does not bear thinking about.

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Devon
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Location: Oxford, England

by Devon

Some good points re: causing an accident. Hadn't considered that. The crank is still solid and unless you see the crack you wouldn't know. It's only about half the way around the BB at the moment. I am however planning to get my new frame ordered today so hopefully I'll have it built in time.....
Campagnolo; because it's a bicycle, not a fishing rod.

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shoemakerpom2010
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Location: Palm Coast, Fl.

by shoemakerpom2010

That area is probably the most stressed area on a frame. No epoxy of any kind is going to work permanent. I would get in touch with Calfee if the frame is out of warranty and don't even think of racing on that.
http://calfeedesign.com/repair/

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