Park Tool CRC-15 Bicycle Crown Race Cutter Adaptor The CRC-15 is used in conjunction with the CRC-1 Crown Race Cutting Tool (not included) to machine 39.8mm crown race seats (1.5" standard) on tapered forks with 1⅛" steerer tubes. Includes precision-machined adaptor body and 39.8mm high-speed steel crown race cutter. The CRC-15 will work on forks with a maximum 1.5" taper of 4.25 inches. Park Tool CRC-15 Bicycle Crown Race Cutter Adaptor The CRC-15 is used in conjunction with the CRC-1 Crown Race Cutting Tool (not included) to machine 39.8mm crown race seats (1.5" standard) on tapered forks with 1⅛" steerer tubes. Includes precision-machined adaptor body and 39.8mm high-speed steel crown race cutter. The CRC-15 will work on forks with a maximum 1.5" taper of 4.25 inches. TRUSTED SINCE 1963 Since our origins in the back of a bike shop in 1963, it has been our sole mission to design and manufacture high-quality tools that empower mechanics and riders of all skill levels to service their bicycles. Each one of our 500+ tools is a product of our decades of experience and expertise in the industry, in the shop and on the trail.