For their Dyna-Sys 10-speed system, Shimano added another cog to their venerable XT level cassette. So like the previous 9-speed versions, the CS-M771-10 XT Cassette has the same Hyperglide tooth and ramp shapes to help the chain move effortlessly across its range.

The XT 10-Speed Cassette uses plated steel cogs for superior durability, but that doesn't mean that it weighs a ton. The largest six cogs are minimal in design and are pinned to two lightweight alloy spiders -- three cogs for each spider. The four smallest cogs go on separately, and the whole batch is secured with a sleek alloy lockring. This cassette is compatible with Shimano's Dyna-Sys 10-Speed shifter and rear derailleur.

The Shimano CS-M771-10 XT Cassette is available with three different cog options -- 11/32t, 11/34t, and 11/36t.

The cogs are configured as follows:

• 11/32: 11-12-14-16-18-20-22-25-28-32
• 11/34: 11-13-15-17-19-21-23-26-30-34
• 11/36: 11-13-15-17-19-21-24-28-32-36