Hi, I am swapping a Shimano Hollowtech Crank/BB setup for a Quarq/SRAM and GXP BB. The BB shell on the bike was already faced/chased in a professional shop when I originally built up the bike.
Is there any need to re-face/chase the bb shell with the new install?
Thank you in advance.
Ideally there should be no need to have this redone. But inspect the faces of the bottom bracket shell, if they are unblemished, appear even, and are free of paint then there is no reason to re-face the shell.
As far as chasing the threads...if the old one unthreads easily and the threads look clean and the new one threads on easily then this does not need to be done again either. Just be careful not to cross-thread upon reinstallation.