Features of the Shimano Dura-Ace FC-9000 Chainring Lighter weight, maintain efficiency Combined with the improved chain guide design to reduce chain drop Maintains High rigidity and reduces weight Optimum Power Transfer 4-arm construction crankset HOLLOWGLIDE 110mm Pitch Circle Diameter 50-34T/53-39T/54-42T/55-42T/52-36T/52-38T Weight: 683g (53-39T, with bottom bracket) 683g (50-34T, with bottom bracket)