For a permanent solution, replace the crank bolt. If that does not help, replace the bottom bracket and the crank bolts altogether.
For all mechanical issues:
https://www.lfgss.com/microcosms/511/
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For a permanent solution, replace the crank bolt. If that does not help, replace the bottom bracket and the crank bolts altogether.
For all mechanical issues:
https://www.lfgss.com/microcosms/511/