With its wide range, SRAM's XX1 11-Speed X-Glide Cassette gives you a clean, simple 1x11 drivetrain. It has a 10-42 tooth spread that gives you pretty much the same gearing as 2- and 3-ring setups without the REDundancy, shifting issues and weight penalty. Yes, you can still spin up your hardest climbs. A key thing to note, is that even with the huge range, there are no huge jumps or dips in the gearing, so your cadence and pedaling stay consistent as you move up and down the entire cassette. The wide open design makes it incREDibly lightweight and aids in mud clearance, giving you cleaner shifting and longer component life. It requires an XD driver hub freebody (sold separately) that further REDuces your wheel's weight and improves the hub connection. Welcome to the future of mountain bike drivetrains.