Opinion on stripped threads in crank arm.

[JohnV]

I'm not having much luck with the drivetrain on this bike. I got the bike out of the shop last month with the new Tiagra crankset and BB and all was going great until last night when I was working out on the trainer. About 9 miles into my normal 20 mile workout, I started hearing a noise coming from the BB that sounded like the needle bearings were grinding. You can feel some roughness when turning the crank manually at a slow speed while connected to the trainer.

I have to take the bike back to the shop that replaced the crankset tomorrow to have them correct the problem. This is really getting old. In a city as large as Tampa, you would think that there are some decent bike mechanics here. I'm wondering if when they put the new BB in, if they greased it before inserting the crank arm.