Specifications Hign-concerned Chemical:None Model Number:CS-R8100-12 Sensitivity:108 Sounds Flywheel Adjustable Gear Number:12Speed Material:STEEL Gear Teeth:11-30T Freewheel Speed:12 PCS Origin:Jp(origin) Components:Freewheel The Ultegra CS-R8100 12-Speed Cassette The CS-R8100 is the first cassette from Shimano's Ultegra road bike series that has 12 sprockets. It is characterized by the Hyperglide + technology, which was initially tested in the MTB area and ensures seamless gear changes even under high loads. Even when kicking out of the saddle or sprinting, you can shift gear safely and immediately. The gradations were chosen so that there is a high level of gait efficiency in all situations and you accelerate optimally. The enlarged teeth of the pinion also contribute to this. A special plus point is the compatibility: CS-R8100 not only fits the new 12-speed freewheel body, but can also be used with conventional Road freewheel bodies. All gear rims are made of steel, with two light aluminum pinion carriers being used. Use: Road Series: Ultegra R8100 Speed: 12-Speed Chainring: 11-30T (11-12-13-14-15-16-17-19-21-24-27-30T) 11-34T (11-12-13-14-15-17-19-21-24-27-30-34T) Freewheel compatibility: Road, Road 12-speed Recommended chain: HG 12-speed (e.g. CN-M8100) Weight:291g(11-30T),345g(11-34T) Compatibility: Shift / brake lever: ST-R8150, ST-R8170, ST-R8060, ST-R9250, ST-R9270, ST-R9160, ST-R9180 Rear derailleur: RD-R8150, RD-R9250 Chain: CN-M8100, CN-M9100, CN-M7100, CN-M6100 Features: Hyperglide + technology for fast, seamless shifting with maximum pedal load Well thought-out 12-fold gradation and larger teeth for first-class efficiency and optimal acceleration in all situations Compatible with 12-speed and 11-speed road freehub bodies Technology: Hyperglide + / HG + Hyperglide + is the efficient further development of the Hyperglide system from Shimano. These are climbing aids and specially shaped pinion teeth that make shifting to larger or smaller pinions softer, smoother and quieter. The system of small rivets attached to the side of the sprocket and milled or pressed-in ramps ensures that the chain is taken along by the next sprocket during the shifting process before it leaves the previous sprocket. Hyperglide + is optimized for faster shifting and shifting under load and, in combination with an HG + chain, has more efficient chain binding, holding power and power transmission. The switching time is reduced to a third compared to the Hyperglide, and the pedal stroke is noticeably reduced. It enables a completely new chain stability and thus offers a safe driving experience.