Crank arm advice

I have an old ZIPP carbon crank set and the left crank arm presents some movement (Play) against the aluminum bushing that goes into the bottom bracket, I have a long endurance race and can’t get the new one on time.
How risky is to loose completely the traction between the carbon and the aluminum bushing?Screen Shot 2021-11-11 at 7.03.14 AM
The movement is about 1mm up-down

With that kind of play (1 mm) I would say that complete failure is imminent. If you really really need to use the crankset, you could apply some epoxy resin to it and hope for the best. Do yourself a favour and change the crankset, risk of it coming apart during ride is just too high.


If it comes apart, the best case would be you don’t crash, but you have to hike a bike to the next aid station / hope you can call someone to get you. Worst case is pretty bad: it breaks when you are out of the saddle, and you crash pretty bad.

Not odds that I would take

Agreed, and since that looks like a square taper there will be no issue getting replacements online/at any bike shop.

Yeah it looks like a square taper and you lost or broke on of the pinch bolts. If that’s the case then most bike shops might have one lying around

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Now that’s a good spot, I assumed he’d taken the bolt out to inspect it - but if you’re right it might be the easiest fix ever!

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Is this the crankset, with an ISIS bottom bracket?

Whatever you do, don’t ride it loose.

Edit: If it is ISIS and you don’t have the hold down bolt, maybe a bolt from a different ISIS BB will work? I’d head down to the local bike store to see if they have a large old parts bin to look through.

Yes that is the one.

The retainment screw is in place, just removed for inspection, the play is en the carbon.

Just removed for inspection

Then you need a new crankset. I wouldn’t ride that in an event far from home. I wouldn’t ride it at all if the carbon has unbonded from the metal.