SRAM's 1070 10-Speed Cassette is a great choice. It's constructed of light and durable materials and boasts SRAM's PowerGlide tooth profiles and shift ramps for quick and positive gear changes every time. This trick cassette also sports a semi-spider construction for a maximum stiffness-to-weight ratio, a lightweight aluminum lockring, and is available in myriad configurations to suit all your riding. There are even models with 36-tooth largest cogs for super-easy climbing.