Surly Ultra New Disc Front Hub - QR x 100mm 6-Bolt Black 32hSurly Ultra New Disc Front Hub QR x 100mm 6 Bolt Black 32h. Surly Ultra New Disc Front Hubs. 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