Sram: GXP is different - and better.Other systems rely on side-loaded bearings to eliminate play, causing bearing wear. GXP captures the left-side bearing between the spindle and the left crankarm 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. Our new Gutter seal system takes a two stage approach in directing contaminates away from the bearings providing longer bearing life. GXP s Gutter Seal design also reduces friction, 35% less drag than the current GXP BB, improving rider feel and performance. Gutter seal system has deeper installation tool grooves which provide stability and support while applying torque to the adapter cups. The design and material choice has dropped 15g out of the GXP BBs.