Originally Posted by
cyccommute
I’ve seen a lot of fixed cups going all the way back to cottered cranks and I can’t recall ever seeing one with that configuration. The cup you show is a common adjustable cup but not a fixed cup. Fixed cups that I’ve seen are almost exclusively have flats on the very outer edges of the cup and use a 36mm (1.4”) wrench to remove. Like this one.
Those are some definitive, confident words for someone who's wrong!
Don't worry, you're not the only one who's been there. I had
the same impression the first time I saw it, but I was willing to ask about it so I don't fall into the same trap. Likewise, another recent BF'er had
the same inquiry about the lack of a flange.
We can't know everything. I wasn't employed at a shop as long as some of the others around here, but I saw a lot while turning a wrench for someone else's dollar. After all that, I'd never seen this configuration.
Always something new to stuff in the cranium!