Vesper MTB Boost Rear HubDescription Onyx MTB hubs help you tame the gnarliest trails on the mountain or blaze your own. Onyx hubs transfer the precise amount of torque you want to the ground when you need it. Nasty climbs on boulders and rock require just the right amount of instantaneous power but only at your command. There is no substitute for absolute control of your machine. Use your precious energy wisely. Uphill or downhill, Onyx ceramic hybrid bearings get you