This is one for the spanner elite!

Just swapping my bike back to geared mode.

The bottom bracket (SLX HT2) has no lateral play in it, but when I spin the cranks; they spin freely for 1 revolution then stop. Also when I spin them by hand, they sound a bit gritty. Do you think it’s time for a new bottom bracket?

Also I’m using a FSA Comet chainset on it if that makes any difference. It fits fine, but I don’t know if the FSA/Shimano thing may be causing dramas?

Cheers

Either the cranks are exerting too much lateral pressure on the bearings so they are turning against too much friction or the bearings are knackered.

Take the cranks off check the bearings with your fingers with the cranks off.

Either replace the bearings (if rough and slow) or refit the cranks doing up bolts to recommended torque.

I’m wondering if the drive side is exerting the pressure. I wonder if putting an o ring on to sit it slightly away from the top hat may work?

Yup had a look at the bottom bracket and it’s borked!
Ordered a new one.