Shimano Ultegra R8100 12 Speed CassetteThe Ultegra R8100 12 Speed Cassette from Shimano is optimised to shift with exceptional smoothness and precision. It features Shimano's Hyperglide+ gear shifting technology for outstanding gear shifting accuracy and efficiency. And it's compatible with Shimano 12-Speed drivetrain systems.The uninterrupted shifting experience of the ULTEGRA R8100 12-Speed cassette range lets you climb, sprint, or cruise without stopping to think about your next gear change. Larger driving cogs maximize drivetrain efficiency and create compatibility with both Shimano 11 and 12-Speed FREEHUB bodies. HYPERGLIDE+ Smooth and Efficient Gear Shifting HYPERGLIDE+ cassettes revolutionized off-road shifting with its seamless shifts both up and down the gear range. Now it's time for technology to change road cycling. Even during maximal efforts up a climb or racing a friend, riders no longer need to back off to perform a shift. In any gear, Shimano ULTEGRA R8150 drivetrains maximize efficiency thanks to larger cogs and retain compatibility with existing HYPERGLIDE FREEHUB bodies. All this while increasing to 12-gears, ULTEGRA CS-R8100 cassettes are the new paradigm in road shifting. HYPERGLIDE+ drivetrain's redesigned cassette and chain promote the next generation of competitive bike riding by enhancing speed, shifting efficiency and smoothness over any terrain. Key Features: Better chain engagement, stronger retention, and smoother pedalling provide greater power and confidence over rapidly changing terrain. Definitive up and downshifting in both directions boost riders' concentration and acceleration. An ultra-efficient drivetrain with smoother power transmission increases comfort and reduces rider stress. A wide range of gearing choices, cassette options and the choice of a single or double front chainring, support a wide variety of riding styles, abilities and preferences.Features: Series: Ultegra R8100 Series Type: HYPERGLIDE+ Compatible Chain: Shimano HG 12-Speed Refined 12 step gear combination provides peak efficiency and accelerating performance for every racing situation Faster, smoother shifts under maximum pedalling force Compatible with new 12-Speed and road 11-Speed FREEHUB body Average Weight: 291g (11-30T); 345g (11-34T)A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.