Originally Posted by
dealingwithit
I'm building up a newish track frame and its got a 70mm bottom bracket, but for some reason the bottom bracket i have for it just wont work. I tried installing it but the threads will not start. Almost seems like the cups are too big for the bottom bracket, but English cups just fall right through. Am i doing something wrong, or do i have the wrong parts?
Sounds like you have an italian bb. 36x24 is bigger than 1.37x24 english. So you will get the effect of cups "falling through", if the cups are english and your bb = italian.