Originally Posted by
agmetal
So, I have this bike with me in Boston now, and I'm beginning the refurb process on it. I got the crank off (turns out that I actually had an original Stronglight crank puller on hand, that I brought up a couple years ago!), but the BB is quite rough and has a lot of play. I have a feeling that the cups are probably in rough shape, so I'm most likely just gonna replace it with a cartridge. The question now is, what's the likelihood of it being a Swiss-threaded BB? There are no markings on the cups.
Very unlikely, I think. Rumors of Motobecane using Swiss threaded bottom brackets are wide spread, but from what I've read these rumors are vastly overstated. My GJ (~75) and GR (72) both had French threaded bottom brackets, as have all others from the same period that I've personally seen or talked to anyone about.