John,
Motobecane intermittently used Swiss threaded BBs on a lot of different models from at least the early 70s until the early 80s.
They also used SR cranks. That's probably where it came from.
BTW, I have 2 identical 1974 Motobecane Grand Jubile bikes. One has a standard French BB and the other a Swiss BB with LH threads on the fixed cup side.
Chas. Colerich Oakland, CA USA
john strizek wrote:
> Today when beginning to mock up a build for my wife based on a Peugeot mixte, I found something I did not know about.
>
> Knowing the bottom bracket was French and that I was going from a steel double to a Japanese single alloy crankset; I picked out of my box of bottom bracket parts what i thought was a set of French BB cups. They were Sakae SR cups clearly marked 35x1. The fixed cup would not thread in. I tried another cup from a pair of Sugino cups. That Sugino cup went right in. when I really looked at the Sakae cups the fixed cup "said" 35x1L. It seems that somewhere I picked up a set of Swiss cups by SR. I certainly never sought any out, only French cups.
>
> I am keeping them for a future project that may have required re-tapping to Italian if not for this fortuitous accident.
>
> I never knew SR/Sakae ever made any Swiss cups, much less French. Has anyone else found such a pair?
>
> With the use of the Sugino cups I am now down to one pair of French cups to use that will give me "modern" axle length choice at a moderate price.
>
> Thanks for letting me run on. I was just amazed at this discovery.
>
> john strizek
> sacramento california in the USA