Bike: 1978 R100S. I've been checking and reassembling a project bike. I noted a slight knock from the drive train while turning the rear tire by hand or rolling the bike around in the garage. It's a much louder knock while under power and riding slowly.
I disassembled the rear drive train up to the tranny. The rear drive and transmission both turn easily and smoothly by hand. The u-joint however seems to have a bit of "notchiness" on one axis. Is this normal or possibly the source of my knock? Any thoughts would be appreciated.