Priekinis žvaigždžių blokas Shimano DURA-ACE FC-R9100 172.5MM 2x11-speed

The DURA-ACE groupset is the result of Shimano's ongoing passion for technology. This is reflected in every single component in the groupset. All components are joined together to work as one, reinforcing each other for unparalleled performance. This is how DURA-ACE achieves ultimate supremacy. The FC-R9100 HOLLOWTECH II crankset's shaping improves upon DURA-ACE's iconic 4-arm design, adding strength and rigidity while minimizing weight. Shimano's Rider Tuned gearing offers a number of chainring configurations with a singular BCD for ease of use and versatility. Through redesigned chainring tooth profiling, the DURA-ACE R9100 crankset is adapted for the latest disc brake frame designs without the need to increase q-factor.Wihout bottom bracketEnhanced design saves 7 g while maintaining rigidityIconic 4-arm constructionOptimized crank arm design strengthens key stress zonesNew chainring tooth profile is adapted for race bike specific disc brake systemsAccommodates shorter chainstays (410 mm) with 135 mm OLDHOLLOWGLIDE chainring constructionGearing (rear): 11-speedCrankarm Material: aluminium, anodizedAxle Material: steel platedLarge Chainring: aluminium, CFRP (anodized)Small Chainring: aluminium, anodizedGradation: 50-34, 52-36, 53-39Crankarm Length: 172.5 mm, 175.0 mmPitch Circle Diameter: 110 mm (4-arm)Chainline: 43.5 mmQ-Factor: 146 mmRecommended Bottom Bracket: BB-R9100 or SM-BB92-41B Pressfit Hollowtech II (not included)Bottom Bracket Shell Width: 68 mm, 70 mmCompatible Chain: HG-EV 11-speed, HG-X11Others: bashguard/chainguard not includedTechnology: Hollowtech, Hollowtech II, HollowglideWeight:50-34: 609 g53-39: 621 gTechnology:HollowtechA lightweight crankset not only reduces the bikes weight, but decreases rotating mass to aid in acceleration. The challenge is to reduce the weight of the crank without reducing its strength and rigidity. Shimano’s advanced forging technology has solved the problem tough the Hollowtech crank. Just like the high quality frame tubing, a hollow crank arm can provide amazing strength and rigidity at very low weight.Hollowtech IIThe concept of Hollowtech II technology is focused on producing a superior crankset, which will maximize a rider’s power transfer. The rigidity of the crankset ensures pedalling efficiency while its weight, a key element of the crankset, you want light, aids in cycling longer distances over which the rider needs to pedal more. Naturally, Shimano strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank.Outboard Bearings: For most frames with 68 mm bottom bracket shells, Hollowtech II with 24 mm axle can set the bearing position outside of the frame to provide better weight distribution and more stability.High Precision Sealing: Hollowtech II cranksets have a high-precision sealing in the bearing area to increase durability maintaining the excellent rotating performance for long periods.HollowglideHighly rigidity hollow structure cuts down on weight yet maintains strength. Better power transfer and more precise front shifting.