If it's with a Shimano chain set, perhaps tighten the hollowgram bolt a bit more before torquing the crank arm up?
It's rival, so just one bolt to tighten. It's fine most of the time, just when it's been going for a while (like after 40 or so miles), which makes me think it's something expanding and rubbing.
@dglshrn started
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If it's with a Shimano chain set, perhaps tighten the hollowgram bolt a bit more before torquing the crank arm up?