If you're looking to upgrade to a one by drivetrain but don't want to buy the group piecemeal, the XX1 Group with Shimano XTR Brakes is a one click, eight piece set to get you out and rolling. The XX1 group is SRAM's top end of one by drivetrain. It includes SRAM's GXP crankarms, which are available in two lengths, 170 and 175mm, that have a Q factor of 168mm. Carbon fiber arms are mated to an aluminum spider that doesn't require finessing to achieve optimal chain placement. They are paired with a 32t X Sync front ring, which is, of course, interchangeable with either a smaller or larger ring depending on how much you like to grind uphill. The X Sync rings are machined with variable thicknesses from tooth to tooth, which essentially locks the chain in place to drastically reduce the possibility that your chain falls off while riding. This groupset includes Shimano's XTR BR 987 Race brakes rather than a SRAM branded brake. Shimano's brakes have proven to be the choice of riders who rip the trails, and the XX1 set deserves a brake equally as stunning as the rest of the group. The BR 987s are disc brakes and the next iteration of the BR 985. The levers are carbon with titanium caliper bolts. Additionally, the lever received a dimpled surface for superior grip. The levers are positioned lower than previous versions and the movement pivots directly toward the bar, creating a more streamlined interface. While they do not have the free stroke adjustment, they still incorporate the reach adjustment. They also feature an I spec body to keep your handlebars as clean as the rest of your new one by drivetrain. The cassette is SRAM's X Dome 10 42t wonder. This 11 speed cassette gives you a wide range of gears without sacrificing clean shifting or speed. The gearing is equally spaced so that once you get used to the range, there aren't any surprise jumps in cadence or missed gears. At first, the cassette body might have you looking a bit confused. SRAM eliminated the lock r...