The 40-Series is the workhorse of Cane Creek's headset line-up. Representing the balance of performance, durability and value, the series incorporates all the features necessary for a robust, lightweight, long-lasting headset. Zero stack uppers press into head tube with very little stack height. Lowers are either zero stack or external cup.Compatible with straight steerer 1-1/8" forksSealed black oxide bearingsCarbon-friendy compression ring captured in top cover, keeping shims in placeSteel crown race with integrated sealsInterlok spacer compatibleItem SpecificationsUpper Stack Height8S.H.I.S. Stem Clamp Diameter28.6 ThreadlessDefined ColorBlackS.H.I.S LowerEC44Weight171Crown Race30Bearing TypeCartridgeColorBlackS.H.I.S UpperZS44Lower Stack Height12