Cane Creek 40 Series IS41 Headset The 40-Series is the workhorse line of Cane Creek's headsets. The 40-Series borrows design features from their premium 110-Series, incorporating all the features necessary for a durable, light-weight, long-lasting headset that represents the perfect balance of performance, durability and value. Cane Creek's 40-series IS (Integrated) assemblies feature drop-in cups with bearings inside the frame. The 40 IS41 headset fits bikes/frames with integrated Campy style headtubes, and will NOT work with External Cup or Zero Stack style frames or forks. Cane Creek Specifications Technical Description IS41/28. 6/H15/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 alloy Weight 77g Manufacture Part Number BAA0074K | Cane Creek | 40 Is41/28. 6-Is41/30 Headset | Black | 1 1/8", Short