i’ve got two frames which i swap parts between (rocky mountain element and spesh enduro). The rocky has a 73mm bb, the spesh 68. Fine with a ht2 chainset due to spacers but i’m considering using a square taper again and that’d mean two bbs. So any issues with facing the rocky down to 68mm. There’s plenty of clearance and the bb threads are deep enough.

just pick up a cheap chainset. it would be a lot easier

Now I’m not a clever bloke…

can’t you just put a BB in each – with the same length axle but a different shell size

I wouldn’t fancy repeatedly swapping a bb over, you’ll end up buggering a thread sooner or later

I’d just have 2 BBs…UN54s only cost a bit over a tenner.

yeah, i guess, you’re probably right. I just don’t see the point of a 73mm bb on an xc frame. And i have a decent 68mm bb already.