Home » headsets » Tapered Headsets » rk TAPERED HEADSETS RK ZS44/28.6 | ZS56/40 Alloy Cap/Cup Sealed Bearings 1-1/8″ to 1.5″ Tapered Steerer Top Nut: 1-1/8″ Cup O.D.: 44/56 Crown Cone: 39.8 Height: 12.5 Technical Diagram RK2ZS44/28.6 | ZS55/40