SRAM Omnium crankset

I have checked the Sram Omnium chain line it's 41mm. So I'm going to space out the drive side of the crank by 2mm. That gives me 43mm, to use with the Goldtec hub spacing of 42.5mm. That all should work very well...thanks again!

If you're thinking of putting a 2mm spacer under the driveside BB cup, you're a braver man than I.

On GPX BBs, crank position is defined by the non drive side bearings, so you really need a 1.5mm negative shim there (i.e. a lot of work with a sharp facing tool). Once you've cut the BB shell down to 67.5mm, adding spacers to the drive side would be a cosmetic measure.

Actually, the first thing i'd do is get some vernier callipers and see exactly how long your BB shell is now, then put the BB cups onto the axle and see what length of BB shell they have space for.

Annoyingly, it appears the MTB version of GPX comes with spacers that could be moved around http://www.sram.com/sites/default/files/techdocs/95-6115-006-000_rev_e_mtb_cranksets.pdf but the road version doesn't http://www.sram.com/sites/default/files/techdocs/95-6115-007-000%20Rev%20A%20-%20Road%20Cranksets_3.pdf