I am installing a new Shimano R9100 BB. I removed the old BB then cleaned and greased the threads. When installing the new BB, everything feels smooth yet I can only get it installed about halfway before I meet resistance. I run into this issue for both drive side and non-drive side.
I’m not sure how far I’m supposed to be able to turn it by hand – I’ve seen mixed information online. I’m afraid that if I force it, I’ll damage the threads.
Should I go ahead and use the BB tool and continue to screw it in?
Should I take it to a shop to have them chase the threads?
by alexschultz13
12 Comments
Chasing the threads is never a bad idea. It looks ok to me, at some point you’ll hit the threadlocker and it will be harder. But first, the stupid question: have you checked the thread rotation of the frame? Is it English or Italian threaded? That’s the most important thing.
Resistance when you hit the blue threadlock???
It’s not cross threaded, so send it home with the tool.
Just to be sure:
Did you check, that the actual BB shell is not obstructed in any way?
Most often, der are cable housings or Di2 components in the way.
If that’s not case I can recommend you check out [BB Infinite](https://youtube.com/@bbinfinite?si=JWpHFB5y4GHmmHAn).
He had some deep insights on the whole them of bottom brackets.
Do both brackets stop when the shell comes in contact with the blue stuff on the thread?
Is it Loctite?
One of the BB Infinite guides say:
For threaded BBs
✅ Inspect/Test:
Try dry-fitting (no grease) if the BB threads in all the way by hand. If you can’t thread the BB all the way in by hand and need a tool, stop → the threaded frame shell needs to be chased.
It’s the threadlocker. You had another one of the same BB in there, so no obstructions. It might take a tool to get past the threadlocker, shouldn’t be much torque till it’s in all the way.
blue dry thread locker is garbage. In some cases can even damage threads ( I kid you not, I snapped threads on brand new Fox 38 on a brake mount). So clean it up with wire brush as good as you want. There is no point of that threadlocker anyway since you usually put grease on threads anyway
I recently installed a new Shimano BB and had the same thing happen – when it hit the threadlock on the threads there was more resistance. It wasn’t cross-threaded – it just needed a little more effort. Using a BB tool I was able to tighten it to the appropriate spec with no problems.
Do it again
Thanks everyone for the help, it was the loctite. I used the tool and a longer torque wrench to screw it all the way in with no problems.
Why would you grease a thread with loctite on it?
Probably combination of the blue loctite and the o-ring in the plastic spacer engaging