The XT CS-M8100 12 Speed Cassette offers the excellent shifting performance that we have come to love from Shimano in both Wide Range and Rhythm step options. Both cassettes feature Beam Spider technology for increased weight savings, rigidity and durability. They also feature the Hyperglide+ technology found in XTR, offering Shimano's smoothest ever shifts in a lightweight package.

The 10-51T Wide Range cassette is perfect for riders after a huge range on their 1x set up. It offers a 510% range with smart gear steps for the ultimate climbing machine.

The 10-45T Rhythm Step cassette still offers an excellent 450% range but is designed with the perfect ratio in mind. You will give up the super-easy climbing gear but gain more even spacing between the gears and the ability to run a shorter cage derailleur. It can be used with either 1x or 2x setups.

Who's this item for: Any riders after a lightweight 12-speed cassette with excellent shifting performance.

Number of gears: 12 speed.

Weight: The 10-51T weighs approximately 470gm, and the 10-45T weighs approximately 461gm.

Materials/Construction: The first ten cogs are made from steel, the 2 largest cogs are made from aluminium.

Cog-tooth span:

• 10-51: 10-12-14-16-18-21-24-28-33-39-45-51T
• 10-45: 10-12-14-16-18-21-24-28-32-36-40-45T

Freehub mounting style: They mount using Shimano's Microspline freehub.