The 40-Series is the workhorse of Cane Creeks 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.Steel crown race with integrated sealsSealed black oxide bearingsInterlok spacer compatibleCarbon-friendy compression ring captured in top cover, keeping shims in placeCompatible with tapered 1-1/8 to 1-1/2 steerer tubes, or straight 1-1/8 steerers with a conversion crown race (sold separately)Item SpecificationsColorBlackWeight155Crown Race40Bearing TypeCartridgeDefined ColorBlackS.H.I.S UpperZS44S.H.I.S LowerEC49S.H.I.S. Stem Clamp Diameter28.6 ThreadlessLower Stack Height12Upper Stack Height8