Standard dual air's, not the u turn version – can these be adjusted internally to 120mm travel?

Ta

130 is easier i think. they come with 2 x 20mm spacers IIRC.

Not sure if links are allowed on here (I'm a noob) so apologies if they are frowned upon.

http://www.sram.com/_media/pdf/rockshox/dealers/TM_MY10.pdf

page 53 😉

PnM

I dropped mine down to 125mm by taking them appart and fitting a stack of plastic spacers/washers. So yes, it can be done but invloves taking the forks appart. Worth changing the oil while you're at it as well.