Priekinis žvaigždžių blokas Shimano ULTEGRA FC-R8100 172.5MM 2x12-speed

ULTEGRA's FC-R8100 crank maintains the same quick, precise front shifting and efficient power transfer that Shimano riders have grown accustomed to, but with even more crank arm length options. An integral part of Shimano's 12-speed road lineup, the FC-R8100 crank builds upon Shimano's legendary front shifting and transmission efficiency. Optimal balance of stiffness, strength, weight and rotational performanceHOLLOWGLIDE structure cuts weight yet maintains strength for better power transfer and quicker, more precise front shiftingFor 2x12-speed drivetrains Weight: 711 g (52-36T) / 700 g (50-34T)Chainring combination (OPTIONAL): 50-34T OR 52-36TCrank arm length: 172.5 mmCompatible bottom bracket type: Outboard (Hollotech II)Crank fixing screw includedSpider/Gear arms: 4HOLLOWGLIDEHOLLOWTECH IIHOLLOWTECH crank armRecommended bottom bracket (not included): Press-fit SM-BB72-41B or Threaded (normal) SM-BBR60Threaded bottom bracket shell width: 68/70 mmQ-factor: 148 mmChain line: 44.5 mmB.C.D.: 110 mmMaterial: crank arms, inner chainring: aluminium (anodized) / outer chainring: aluminium (anodized), carbon fiber reinforced polymer (CFRP) / axle: steel (plated)Compatibility:Front derailleur: FD-R9250, FD-R8150Bottom bracket: SM-BBR60 (thread type), SM-BB72-41B (Press Fit)Chain: CN-M9100, CN-M8100, CN-M7100, CN-M6100