This Cane Creek 40-Series Conversion Crown Race will allow you to run a 1-1/8" straight fork with a 30mm crown race seat in any Cane Creek headset with a 1.5" lower bearing. It's made of durable steel and has a low-friction face seal that runs lightly against the face of the lower cup to keep the bearings from being contaminated with mud and muck spraying up from the front wheel.