Surly Ultra New Front Hubs, Non-Disc. Features: 6061-T6 forged hub shell (same as the Surly New); 6901 bearings Axle is quick release and bolt-on compatible Stainless 6mm bolts are included; quick release skewer is NOT included 4130 CroMoly axle and stainless cones; agressive knurling on cones and bolt caps for reduced slippage New axle/cone system uses uses a specific shouldered axle that allows the hubs to be completely adjustment free and simple to service Specs: Front AxleQR x 100mm Weight230g Center to Flange, Left32.2 ColorBlack Flange Diameter, Right54 Defined ColorBlack Hub Drilling32 Flange Diameter, Left54 Hub/Brake CompatibilityRim Brake Center to Flange, Right32.2 Substitutes: HU0596, HU0810