Truvativ: WHAT THE WORLD SPINS ON A tough bottom bracket that will go as hard as you. The PowerSpline has a heat treated chromoly 12 spline spindle to make sure it can go the distance with even the most demanding riders.FEATURESThe PowerSpline has a heat treated chromoly 12 spline spindle to make sure it can go the distance with even the most demanding riders.ISO 4210 compliant. See Declaration of Conformity for details. SPECIFICATIONSBB-frame interface English/BSA 73mmCrank-BB interface Power SplineBearing type n/aSpindle diameter n/aSpindle length 118mm SpindleChainline n/aSupport E-type FD n/aCup material n/a