Originally Posted by
loubikes
Thanks bikemig, I actually have the BB off now ... EXCEPT for the fixed cup. I have now broken two 1/2 bolts trying to remove it using Sheldon Brown's suggested method for BB removal. Really wondering if it's Swiss but I can feel the threads from the other side and I'm 99.9% certain they are right-hand threads.
Are there any markings on the fixed cup face? If you're lucky, they will explicitly give the thread spec: "35 x 1" for French; "35 x 1 P1 S1" for Swiss. But older components may have more arcane markings:
Source: Sutherland's 4th Edition