Sram pressfit gxp alloy bottom bracketa variant of the external bottom bracket pressfitcut 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 theres no change to the crank spindle length and diameter remain the same gxpis different and better other systems rely on side loaded bearings to eliminate play causing bearing wear gxpcaptures the left side bearing between the spindle and the left cranka