Shimano INTERNAL HUB GEAR 8-SPEED FOR DISC, SG-S7000-8, ALFINE, 36H, Silver Internal geared hub for disc brake. 8-speed Top Normal structure adopted for more sporty cycling. Increased tolerance for shifting while riding uphill and under heavy loads Gear ratio 306% O.L.D. 135mm Spoke size: #13/#14 32H/36H Axle length: 187mm Color: Black or Silver Wt: 1680g