Sram / Truvativ Press Fit Bottom Brackets
Sram's saw the opportunity to make a better press fit system where all the best from BB30 and PressFit bottom brackets would be combined into one captivating package. PressFit 30 will feature an integrated seal, pre-assembled into the cups, to further prolong bearing life. 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. This bottom bracket is designed for 30mm spindle cranksets.
Frames will need a 46mm inner-diameter bottom bracket shell to accommodate this system. PressFit 30 for road will require a 68mm wide shell while PressFit 30 for MTB will require a 73mm wide shell.
Sram's GXP Press Fit bottom brackets is variant of the external bottom bracket. PressFit BB's cut weight by up to 40 grams and provide easier installation by allowing you to press the bearing cups into the frame instead of threading them. There's no change to the crank — spindle length and diameter remain the same.