My guess, is that the taper on the (alloy) crank is damaged, so no amount of tightening the bolt is going to keep it tight. If that is the case, you probably need a new crank.
@cip1000 started
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My guess, is that the taper on the (alloy) crank is damaged, so no amount of tightening the bolt is going to keep it tight. If that is the case, you probably need a new crank.