40-Series The 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 light-weight long-lasting headset. To make it easier we developed consistent graphics interchangeable parts and over 40 configurations to meet almost every need. Sold in straight and tapered assemblies or tops & bottoms Cane Creek's 40-Series offers the largest fitment range of any headset line on the market. Precision engineered by Cane Creek in Fletcher NC.Technical Description IS41/28.6/H9/K|IS41/30/H1 Top Type IS - Integrated Top Head Tube Inside Dia. 41.1mm Stem Clamp Dia. 28.6mm Top Stack Height 9mm Top Bearing Type Black Oxide Sealed Bottom Type IS - Integrated Bottom Head Tube Inside Dia. 41.1mm Crown Race Seat Dia. 30.015mm Crown Race Type Steel Face-Sealed Bottom Stack Height 1mm Bottom Bearing Type Black Oxide Sealed Material 6061 Weight 71g