Hi i am fitting a square taper un bottom bracket with the plastic cup on the non drive side. I first fitted the platsic cup and then the metal side with the bb. I check the threads first on both sides using the metal thread and the threads are fine and go all the way through.
The metal side does not do all the way up though by about 1/2 to 3/4 of a mm.
Should i get a spacer so the flat end is putting pressure on the flat end of the bb or just leave the gap?
thanks.

