is there anyway to tell what threading my BB is without taking it out.
some sort or external indicator?
possibly the origin of the frame?
or sizing of the cup?
Measure the shell width.
English BB shells are 68mm wide and Italian shells are 70mm.
Good tip !
And obviously if it is Columbus tubing, and an Italian brand, there’s a good chance it’s Italian threaded…
Dunno about that. Columbus tubing is not an indicator of Italian threading. In fact, Columbus tubes doesn’t mean that the BB shell is necessarily Columbus either.
But it’s easy to measure so it doesn’t matter really.
I’m just saying in the majority of cases, Columbus steel tubing + Italian marque BB shell = usually Italian thread that’s all…