Industry Nine Classic hubs are the heart of your wheelset, everything revolves around them, literally. Every Classic mountain hub is made start to finish in i9's Asheville, NC machine shop. From turning and milling bar stock 7075-T6 aluminum for shells, axles and encaps, wire EDM cutting A2 tool steel for pawls and driverings, to their own in-house anodization lab, every step of design, engineering, manufacturing, and assembly is done on premises to i9's exacting standards. Hydra Classic mountain hubs are loaded with features every rider will appreciate such as revolutionary 0.52° engagement, generously low weights and an intuitive layout that can be serviced without any proprietary tools. The range boasts a universe of standard options in terms of axle fit, spoke hole drillings, disc rotor mounting, freehub bodies, and colors. All Photos show the SRAM XD Freehub Details: Hub Drilling: 28h or 32h Hub/Brake Rotor Compatibility: 6-Bolt Disc Spoke Interface: J-Bend Bearing Type: Sealed Cartridge