Not entirely sure what I’ve gotten wrong. How tight should the alloy bolt be, bit paranoid of stripping it, does it stop/bottom out completely, or does it just tighten?

Took the bolt off and the axle looks to have bottomed out on the crank arm, but the collar reached the end of it’s threads and just spun. It was fine with an old CK BB 3 spacers and a 68mm shell, but somethings not quite right in the new 73mm shell with 1 spacer and an XTR BB?

It’s 45-55nm. Pretty tight, it’s a big ol bolt. As for whether it bottoms out, I’m not sure, it doesn’t feel like it but I wouldn’t want to say 100%.

What do you mean with the bit about the collar?

The collar that’s wound on to load the bearings only has about 2mm of movement, there was more than that of axle to take up.

one of mine did strip in terms of fitting an allen key so it is worth being cautious- wouod not tighten but it did undo thankfully

I doubt it bottoms out or else they would not give a NM reading they would just say till it wont turn- guessing there tbh but seems to make sense to me

As for your problem sorry not sure

It does bottom out. 50Nm is when it’s all the way on and the bolt meets the axle. I’ve fitted two this month.

Hmm. Don’t think either of mine has that much play. Not being funny but are you absolutely sure it’s a 73mm shell? (and that you’ve fitted a 2.5 spacer? I once fitted a 1mm one out of basic inattentiveness…) Just to eliminate those…

Right, thinking again about the bolt- the bolt doesn’t bottom out but the arm bottoms onto the axle. Sorry, I could have been more helpful there earlier.

Pretty sure it’s a 73mm shell and the spacers are the right ones (but worth checking), it definitely isn’t 68mm. Guess the shell might be undersized though? The old cranks were GXP so wouldn’t have noticed.