While installing a euro bottom bracket (BSA threaded), I heard a crack while tightening the NDS. The frame is aluminum and I'm not sure what the material of the bottom bracket is.

Bottom bracket


After I heard the crack, I unthreaded and it was slightly gritty towards the end, but still threaded and unthreaded from the frame fine. It appears that I'm able to get up to a certain torque before it cracks again.

Before I get flamed, I'd like to defend myself in saying that it was not cross threaded, and the torque wasn't ridiculous. The drive side was in fact torqued harder than the non drive side, so I figured it would be fine.

How much did that damage the threads? Since it's still holding some torque, am I fine to ride the bike? If I took it to a shop, would they be able to simply retap the thread? Should I order a new bottom bracket cup if they retap the thread?

  • Is this not a steel frame? Does anything have visible damage? Jun 26, 2021 at 2:41
  • Also were the threads well lubricated and what with? Jun 26, 2021 at 7:08
  • @NathanKnutson It was an aluminum frame. The threads were lubricated with Park Tool PPL-1 (essentially marine grease). Jun 28, 2021 at 15:44


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