Thumb- push actuation on both upshift and downshift
DiRT (Direct Route) cable routing to rear derailleur
Adjustable clamp position
Sporting more than just cosmetic upgrades over X9, SRAM's X0 trigger shifters still belong at the top of the heap. When SRAM first introduced their push- push lever action and instant release technology, it changed the way drivetrains were designed. The response from Shimano was to make their shifting more "SRAM-like," so it's safe to say that the engineers at SRAM hit the bulls-eye.
There are several features that set SRAM X0 1:1 shifters apart from the rest. 1:1 Actuation means the derailleur moves the same distance as the amount of cable that is released or pulled by the shifter, all the way across the cassette. Other shifting systems vary the amount of derailleur movement per cable movement according to which gear the chain is in, which can cause varying performance, especially in muddy conditions or under load. 1:1 Actuation provides a consistent, accurate, easy to maintain shifting action all the time. Zero-Loss Travel technology is another signature SRAM feature. Zero- Loss simply means, well, zero loss—when you push on the lever, for an upshift or down shift, the cable is engaged instantly—zero loss of movement. There is no middle-ground where you're waiting for the shift to come. Gear changes are instant and precise. Also adding to the instant, solid feel of the X0 shifters is the cable routing. Instead of an elongated loop of housing where the cable is clamped to the derailleur, the cable is routed directly to the derailleur body. This eliminates excess friction from the cable moving inside an extra piece of housing.
Finishing touches abound on the X0 trigger shifters also. Ambient thumb lever angles are adjustable on both right and left shifters, letting you adjust for your stubby thumbs, or you can bunch up both paddles right next to each other to keep your hand movement at a minimum. You can also move the shift pods in-board or out-board about 1/4" to better fit your brake levers or your hands. Carbon fiber covers cap off the embarrassment of riches these shifters provide you with.