yes T2 is 7 speed, T3 is 8 speed. I just saw on their website that the "T" series (the ones with clutches) are designated as 1x only, it's the "A" series that is for 1x/2x/3x, but they don't have a clutch... I can't see why the "T" models wouldn't work with a double chainring, so long as there...