Cane creek 40 series zs49 zs56 tapered headsetcane creeks 40 series headsets provide unrivalled performance durability and value for money and this zs49 zs5640 model benefits from precision engineering for a snug and secure fit the cups are equipped with fully sealed cartridge bearings and a sealed crown race preventing water ingress for consistent smooth rotation featuresmaterial 6061 aluminiumsteerer tube od1 18 to 15 taperedupper headtube id49 00mmlower headtube id55 95mmfork