GXP is different - and better. Other systems rely on side-load bearings to eliminate play, causing bearing wear. GXP captures the left-side bearing between the spindle and the left crank arm and allows the drive-side bearing to float axially on the spindle. There's no need to side-load bearings during adjustment. No excess wear and a much simpler installation. Just tighten to the proper specifications and you're ready to roll, worry-free. GXP's two bicycle-specific cartridge bearings and eight seals ensure a smooth, long-lasting ride. SRAM's new gutter seal system takes a two stage approach in directing contaminates away from the bearings providing longer bearing life.