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.

I’m pretty sure you’re supposed to fit the metal end, and then screw the plastic end in after. The metal end should be flat to the BB cup, the plastic end doesn’t always get there.

Edit – you sure you got the right length of shell?

I’ve got a spacer there – it’s too long for the frame…

Always fit the main body of the BB first then the loose cup

ok thanks. So do i still need a spacer for the plastic side if it does not tightened fully.

Actually that makes complete sense as the load is on the drive dive side.

Thanks

Yup screw in ds first then tighten nds

You don’t need to use a spacer on the non drive side if its a very small amount of thread showing.

cheers. all together now. 🙂