nickc3

So, this is second time I've done BB maintenance....First time went smooth.
This time, just did a cleanup of grit and re-greasing. Re-installed - everything shifted OK in stand. Went out, and it was not shifting into big ring most shifts. Brought it back home, uninstalled pedal side...gave crank side a good smack a few times to make sure shaft was all the way though. Re-tightened, tested shifting...seemed better. Out on street..seemed OK, but then realized same issue.

Any ideas? Should I re-install the bottom bracket as well? Perhaps tighten more? Could the Derailler just have gotten mis-adjusted? Or perhaps you need to adjust the FD (DI2) sometimes after reinstalling a Crank?

Thanks in advance for help or guidance.

79pmooney

You might tell us what bike you have or at least the crankset. It sounds like the crank isn't slid onto the BB spindle quite as far (or further; you haven't said how the shifts differ).

Press fits are not an exact science, I find I usually have to tweak the limit screws a little after taking off and re-mounting a crankset. And I would fully expect to need to also tweak the cable barrel adjust if I ran index. (Another reason I remove cranksets as seldom as possible.) I'll let the brifter/Di2 folk give you better advice but my dollar says they'll just repeat what I said with details.

nickc3

Hi, the BB is threaded (Shimano Dura Ace)

Its a Dura-Ace standard crank

The difference in shifting is that it doesn't shift into the big ring. The derailler moves, but I assume not far enough...because perhaps the crank isn't properly re-installed?

SpedFast

Just for haha's did you check whether the DR is still aligned while you had it in the stand and it shifted onto the large chainring? What you're describing sounds like the DR moved or you need to set the outer (H) stop to allow the cage to move farther out. Good luck.

nickc3

I micro adjusted top limit 2 steps and that seems ok in stand. I'll check on road

But should I be concerned but how to make an adjustment after maintenance? Is it possible my reinstallation wasn't exactly good? Even though I reinstalled it three times and I was still having that issue? I don't recall doing anything that would have misaligned the FD

nickc3

So, went for a 20 mile ride.....shifting perfectly for 19 of those miles. Then at end, it started not shifting into the large ring again!!!!!!!!!!!!!!!! What could be happening? Could the crank be loose somehow? Very strange.

oldbobcat

It sounds like the spindle is sliding around sideways between the bearings. Loosen the pinch bolts on the left crank, tap the drive side crank with a mallet, and re-tighten the side-load nut on the left.

nickc3

Yes. Thanks

​​​​​​I think I may actually just reassemble the whole thing again

Maybe I'll do the mallet things first

If it fails just start all over

And if that fails....LBS!!! SIGH

Iride01 

If you understand what the function of the stopper plate is on the left crankarm and you correctly used it during the installation of the crank arm, then your crank arm isn't the issue.

But since you jumped at the idea that you need to tap on it with a mallet, then you probably have overlooked the stopper plate use entirely. And the stopper plate may even be damaged now.

nickc3

I do understand the stopper plate function and reinstalled it correctly. It is not damaged . That said, surprised to hear that you think that is issue ... Correct me if I'm wrong but purpose of it is safety in case the bolts loosen up. Prevents crank from flying off or moving of volts are loose. I properly torqued the bolts
​​​​​​thx again

Iride01 

If you were able to push the stopper plate in, prior to tightening the bolts on the crank arm, then the crank is far enough on the spindle.

BTinNYC 

Check the the frame support grub screw on the FD.