SHIMANO Tiagra FC4500 170mm 9spd 52-39t Crankset BB Shell Width: 68/70mmChain Compatibility: 9-SpeedChainring BCD: 130mmChainrings: 39/52TCrank Color: SilverCrank/FD Type: Road DoubleCrankarm Length: 170mmCrankarm Length: 170mmCrankset BCD: 130mmCrnk Clr: silverPedal Spindle: 9/16"Rings: 52-39Spin: Not ApplicableSpindle Interface Type: Hollowtech II