I ebayed a brand new one for the bargain price of £15. Sadly it came with no instructions and the SRAM site doesn’t seem to have the manual for this exact model either?

http://www.sram.com/service/truvativ/42

Just wondering what the bits are for. So I press the thing into the frame, then install by BB as normal. I’ve still got 4 little transparent discs, a wavey thing and a little (2mm? spacer left).

Similar GXP30 model thing?

So, with a standard 73mm bottom bracket I need to stick the wavey thing, 2.5mm spacer and a transparent disc on the drivetrain side? Then mount the other side as normal?

“73 mm bottom bracket shell width
: Install the wave washer, one 2.5 mm
shim, and one 0.5 mm shim onto the crankarm spindle.”

Man, these things are convoluted.

Put the adaptor in a vice and fit the BB, only torque it up lightly – I don’t remember the actual torque. The spacers are to get your chainline correct. Wavy washer goes in on the drive side no matter if you use the clear spacers.