Cane creek 40 series zs44 ec4940 tapered headsetthe 40 series sets the standard for performance durability and value drawing from the premium 110 series design the 40 series incorporates all the features necessary for a durable lightweight long lasting headset this headset consists of a zs44286 top assembly and an ec4940 bottom assembly features steerer tube od1 18 to 15 tapered upper headtube id44 00mm lower headtube id49 61mm fork crown seat od39 79mm top stack height