So I'm retrofitting an old mountain bike with a bafang mid-drive and this frame has been fighting me every step of the way. For starters, it had an old-school 1 piece pedal crank, so the bottom bracket is huge. I've also had to reroute the rear gearshift cable due to motor clearances.I just installed a USA to UK bottom bracket adapter in the frame to fit the motor. Now the motor appears to be slightly tapered on the drive end and it doesn't fit flush against
the bottom bracket. It's leaving about a 2mm gap.
Has anyone had this happen? should I just shim it and forget it, or is this a bigger problem?