Originally Posted by
Salamandrine
Again, it is normally possible to screw an English adjustable cup into both sides of a french BB. The pitch is different, but since the cup is a tiny bit smaller it's close enough. If it was BSC it would not have a right thread fixed side.
Also they could have been chased with a BSC tap at some point. If you want to know if that's happened, check with thread gauges and a magnifying glass for best fit.
OK, whew good. Most of the work I've done has been on bikes with all English/ISO threading so this is new ground for me.
When I removed the cups when I broke the bike down they were good and tight.
Is there any functional reason not to use BSC cups instead of trying to chase down a French BB? Especially since I just found and bought an NR BSC adjustable cup to use
Thoughts? Thanks SO much for the clarification.