Will there be compatibility problems for crankset and bottom bracket for vintage motobecane? Most concerned about compatibility of bottom bracket/crank area. Not sure of model and year, any ideas? Some specs...1020 tubes,forks and stays, weinmann 610/vanqueur 999                                              brakes, SR headset,suntour derailleaurs....obviously some rebuilding done, but does say something about compatibility issues.     Thanks!!! Blueskynolimit 

ps can someone tell me how to "attach" photos?
Old Motobecanes are all over the place with BB threads. There are large numbers of them each with French, ISO/English, and Swiss. (Swiss may seem odd, but the deal with it is that it's the same 35x1 thread as French but with a left-threaded drive side cup, to prevent loosening. So it's kind of a natural progression from French, although I don't know the exact history with Motobecane using it.) Many but not all BBs have their thread type inscribed on the outside of the cup. I'm sure there's also a heavy correlation with where in the world the bike was originally sold - i.e. if it was for the domestic market it's probably not ISO.