There has been an annoying creak and a bit of play in the transmission of my bike. I’ve changed virtually everything in the drivetrain, serviced the pedals and still there’s a bit of ‘something not right’

The last thing down to change was the BB. That’s coz the XT HT2 one in there was new in February.

I come to change it and the whole non-driveside BB cup falls out. Disaster! I start digging around for warranty info and panic sets in.

After a restorative cup of tea I have another look. The frame doesn’t look bad; the BB threads are well eroded.

My theory is the BB was not fully tight, and has been allowed to rock slightly in the threads for a few months. This has caused the wear. The BB is softer alloy than the BB shell as a sacrificial part and the frame will be fine.

With a clean up the new BB has gone in smoothly, torqued up perfectly.

Am I in the clear?

Or do I need to get it helicoiled?

Any experiences?

see how you get on is what I’d advise.

You can get deeper cup BB’s which might help catch ‘new’ threads.

Saint BB has deeper cups. I had a similar issue with a (non Shimano) BB – the threads on the BB cup just folded and it fell out eventually, shell threads were fine however.

Was the original BB made out of cheese or something?

Threads are fine for running into the frame, it’s gripped it nicely.

I’ve only got another XT which might only be in the frame long enough for a Phil Wood to arrive from Sideways…

If it’s in and torqued up you are in the clear, heave a sigh of relief and continue as you were.

I had a Hope HTII cup fall out once. I thought I had knackered the frame but both I and a LBS looked at it and concluded that the frame was still fine. Phew.

As above, if concerned, Saints apparently have longer threads.