First post, so hi all.

I've picked up a 2005 FSR XC Comp frame that I'm just starting to build up.

The bottom bracket shell has been faced and is 68mm, so I'm guessing the previous owner had an external BB installed. The front mech is adjusted so it's almost touching the seat tube, and I've read that this is a symptom of having too short a BB axle. I've not been able to find a spec, but I've seen a vague mention that this frame should use a 118mm BB axle, and they seem to be pretty rare. I don't want to run it with unnecessarily small clearances, so, I'm wondering what BB setup to go for.

I'm not quite clear how axle lengths relate to Hollowtech-type chainsets (which I have on my S-Works HT) - as far as I can see there is no opportunity for offset adjustment on the drive side - is that true? Does the 118mm length only apply to square-drive BBs?

Any advice gratefully received!