It sounds like your cranks have worn internal tapers, and are moving on the spindle. Once they do this they are pretty much toast, as they will always move a bit and wear some more, so the alloy becomes loose on the spindle again. The bolt is then loose too.
There isn't really a cure, apart from replacing them.
It sounds like your cranks have worn internal tapers, and are moving on the spindle. Once they do this they are pretty much toast, as they will always move a bit and wear some more, so the alloy becomes loose on the spindle again. The bolt is then loose too.
There isn't really a cure, apart from replacing them.