Built for total chain control, each tooth’s thickness is CNC machined to fit better into the chain’s inner and outer links. Eight available X-SYNC™ Direct Mount chainrings (26-28-30-32-34-36-38-40) let you tune your gear range to match your terrain, wheel size and riding style. BB30 Besides serious weight savings, this bottom bracket means narrow Q-factor, more ankle clearance, greater bearing durability and stronger crank construction. BOOST With revolutionary advancements in bicycle componentry, like SRAM’s XX1, X01 and X1 drivetrains, mountain bike designers have been given almost limitless freedom to focus solely on the performance of the bike. Each advancement demands that the entire package works flawlessly. Aggressive trail and enduro riders have been increasingly enjoying the benefits of larger wheels, but many still view 27.5″ and 29″ wheels as a possible weak link. Which is why SRAM has developed an open standard with Boost compatible components for SRAM drivetrain, hubs and RockShox forks GXP’s Gutter Seal design cuts friction and weight-improving both feel and performance A variant of the external GXP bottom bracket, PressFit cuts weight by up to 40 grams and eases installation by allowing you to press the bearing cups into the frame instead of threading them. It requires no change to the crank spindle length and diameter. This is a new design led by SRAM. It’s all the best from BB30 and Press-Fit bottom brackets in one captivating package. This bottom bracket is designed for 30mm spindle cranksets. The key difference with PressFit 30 is how the bearings are fitted into the frame. Bearings are housed in nylon cups which will be pressed into the frames bottom bracket shell. PressFit 30 will feature an integrated seal, pre-assembled into the cups, to further prolong bearing life. Frames will need a 46mm inner-diameter bottom bracket shell to accommodate this system.