I have a 68mm BB going into a 68mm frame. Its a es51 octalink BB. The trouble is. I have now got two new cups for the non drive side…and they just don’t fit (from two people who really know what they are talking about)…besides…i thought all shimano non drive side BB cups should fit (aslong as they are for 68mm)?

The BB shell is clean, the BB cups are clean…they obviously aren’t the correct one. Does anyone know what i need?

Are you remembering that the thread is the reversed on one side- I think it is the drive side so you need to turn it anticlockwise to tighten it? Also there are Italian threaded and English threaded bottom brackets.

Yes i’m remembering all these things. Thanks though.

I can’t get the cup onto the BB at all even when its not on the bike. It just won’t fit even with tapping with a mallet.

The anwser…if someone who googles the archives ever wants to know…is that Shimano BB cups are not universal, they are different sizes. Sq taper and Octalink are not interchangable.

Do they actually thread in the BB shell without the main BB assembly in there?
If not make sure they’re not italian threaded (unlikely but you never know). Perhaps take the frame to the LBS and get the threads chased?

nope…the inner diameter of the shell is too small…you need to use octalink specific cups…all sorted now.

Dont suppose you have any spare square taper cups going spare Joe ?

andy@mobileoffice.plus.com