Home » headsets » Tapered Headsets » p504a TAPERED HEADSETS P504A IS41/28.6 | IS52/40 Alloy Sealed Bearings 1-1/8″ to 1.5″ Tapered Steerer Top Nut: 1-1/8″ Bearing O.D.: 41/52 Crown Cone: 39.8 Height: 5.5 Technical Diagram