All,

I have a boardman CX bike, with BB30 (that is making a lot of noise and needs replacing). I’m getting a new road bike, with shimano external BB, and I’ll be replacing that with an Ultegra crank / external BB. meaning I’ll have a spare shimano Crank / BB

Can I simply remove the BB30 fitting on the CX bike, and simply fit the shiimano BB / Crank as per normal, or are the threads / diameter of the BB shell different?

If it’s a proper BB30 shell there are no threads.

You can get adapters – Wheels Manufacturing do a good one, which presses into the BB30 shell and allows you to screw in the HT2 cups.

I’m not sure tbh, I’ll have to strip it down this weekend, I would have thought it will be though, so an adapter me be the way to go…

Is it BB30 or PF30?

Praxis do a fantastic PF30 converter BB which is widely regarded as being the best as it screws together both sides which helps to prevent the bearings from walking out of the frame. It’s also about half the price or the newly-launched Hope item iirc.

Wheels Manufacturing guide to BB adaptors

I have a BB30 to Shimano adapter lying around if you need one.

cheers Paul, I’ll check it out this weekend, and judging by your username I may be able to pick it up 🙂