Crown races for Cane Creek headsets fit a variety of lowers and crown race seat diameters. - Compatible with 10-, 40- and 110-Series headsets and backwards compatible with S and XX Series - Integral mold seals keep out the elements - Compatible with 52mm lower headset bearings - Compatible with 30mm (1-1/8") straight steerer tubes - Durable steel construction - Allows the installation of a straight steerer fork without changing out the headset lower