Hi all,
I’m trying to solve a squeak/creak that only appears after ~10-15 minutes of sustained load (sometimes earlier). At first the bike seems quiet, then it starts squeaking pretty consistently under torque.
I originally suspected the bottom bracket and already bought a new BB, but when taking things apart I noticed the crank arm seems to be rubbing / grinding against the BB cup. You can clearly see wear marks on both the crank and the BB cup plastic (see photos). Just to make sure, I already cleaned and added some grease to the BB, but that didn’t solve it – I assume it relates to the grinding.
Now I’m wondering if this is simply an assembly issue (missing spacer etc.) rather than the BB itself – or something else entirely. Before I press in the new BB and make things worse: any ideas what I’m doing wrong / what to check next? 😅
Crank: Shimano GRX RX810
BB: Token Ninja Lite BB4124 (ca 10k km if that matters)
Thanks a lot!
by Impressive_Land_4413
3 Comments
The bearing’s shield should be every so slightly proud of the bottom bracket’s attachment splines, but it’s not. I presume if you used a Shimano PF86 BB there wouldn’t be this tolerance issue.
However, this is a case where I would use a 0.5mm or 1mm *spindle* spacer to create the needed (and missing) separation between the arm and the bottom bracket. The safety pin should still fully engage with that spacer present.
You didn’t install it correctly, undertorqued
Or
the bb is out of specs. These chinese bbs sometimes have problems, only prowheel is spot on
Take the BB out and check the frame. Make sure the shell width is in spec. I’d also look for facing marks on the shell. You’d be surprised how many bikes are poorly prepped before assembly
Just realized this is pressfit. That’s why it creaks. Get a thread together one.