Bottom bracket doesn't want to insert.
I just bought a new Leader track frame, and I'm trying to put in the BB, but neither side wants to go in. It wants to cross-thread. Everything is standard English threading and new (BC 1.37X24T, 68X111), and I am turning them the correct way. Neither side will reach a full turn before stopping, and I have tried about a thousand times. I haven't forced anything, and I'm only using my hands. It's a mediocre Sunrace BB, but I'm in Mexico, and it's the only one I could find that would give me the chainline I want. Furthermore, that shouldn't stop it from entering the frame. Any advice out there? Am I doing something wrong, or is there another measurement on the BB that could be causing me a problem. I have put in a number of BBs, and I have ruined one, so I know not to force anything. It's frustrating to experience this with all new merchandise.
Have you tried flipping it around?
I've come across sealed bearing BBs with the removable cup on the opposite side from 'normal' BBs before.
Problem solved. Even though it was new, I cleaned the threads with a knife, and then it decided to go in nice and smoothly.
Your first problem was buying a Leader.