Cassettes/Freewheels

Shimano's Ultegra 10-Speed Cassette delivers pro-level shifting and durability. The computer-enhanced tooth shapes and tough cogs mean you can shift quickly, precisely and smoothly even under pressure.

When it's time to replace your old 8-speed cassette, check out SRAM's PG-850. Its steel construction and SRAM's PowerGlide technology combine to deliver miles of solid shifting and outstanding durability.

When it's time to replace your 9-speed cassette, check out SRAM's PG-950 cassette. It delivers solid shifting and durability ride in and ride out for your 9-speed rig.

Machined from heat-treated, chrome-plated chromoly, these seriously tough cogs will hold up to massive track sprints and crazy skid-stops. Surly's Track Cogs are strong, shiny and they come in two widths and sizes from 13T to 22T so you can select the perfect gear.

• Steel construction on all but the largest aluminum gear • Nickel-plated finish for corrosion and wear resistance • Dyna-sys 11-speed cassette with "Rhythm step" gearing for closer gear ratios and smoother shifting performance • Fits Dyna-sys 11-speed and current Shimano 9/10-Speed MTB hubs • The largest cog (40t) is positioned inboard and above the drive-side flange • Hubs with tall drive-side flanges may not be compatible due to spoke interference

Dependable, quick shifting awaits with Shimano's Saint/SLX 9-Speed Cassette. It features chrome/nickel-plated steel sprockets mounted to a aluminum carrier for an ideal blend of durability and low weight. Plus, the cogs are ramped and machined for those flawless shifts that Shimano is known for.

Shimano's SLX Dyna-Sys 10-Speed Cassette features chrome-plated steel sprockets mounted to an aluminum carrier for an ideal blend of durability and low weight. Closer gear ratios in the middle of the cassette ensure you'll have the perfect gear for the trail's ups and downs. Plus, the cogs are ramped and machined for flawless shifts with the 10-speed chain and Shadow rear derailleur (both sold separately).

Shimano's Sora cassette is an incredible value for your 9-speed drivetrain. Crisp shifting and a low weight keep your mind focused on having fun on your bike and not adjusting it. This cassette comes in a range of sizes to suit your riding style and terrain.

Shimano's Ultegra 11-Speed Cassette delivers pro-level shifting and durability. The computer-designed tooth shapes and tough cogs mean you can shift quickly, precisely and smoothly even under pressure. Rider-tuned gearing options offer a range of cassettes to suit your riding style.

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.

SRAM's PG-970 9-Speed Cassette is the perfect replacement for your worn-out gears. It features a rugged steel construction for awesome durability and SRAM's PowerGlide technology for smooth, precise shifts.

SRAM's PG-970 9-Speed Cassette is the perfect replacement for your worn-out gears. It features a rugged steel construction for awesome durability and SRAM's PowerGlide technology for smooth, precise shifts.