Cassettes/Freewheels

The uninterrupted shifting experience of the Shimano Ultegra CS-R8100 12-speed cassette range lets you climb, sprint, or cruise without stopping to think about your next gear change. Larger driving cogs maximize drivetrain efficiency and create compatibility with both Shimano 11 and 12-speed freehub bodies. Shimano HYPERGLIDE+ technology is integrated to provide seamless shifts both up and down the gear range. - Refined 12 step gear combination provides peak efficiency and accelerating performance for every racing situation - Faster, smoother shifts under maximum pedaling force - Compatible with 12-speed and road 11-speed freehub body

• Easy-on, easy-off • Available in two chain widths and two colors • Available in six teeth sizes

• Steel • 8-speed

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.

Pair this cog with your Shimano-compatible rear hub, spacers and a lockring (sold separately) and discover the joy and simplicity of a singlespeed without the cost of a new wheel. Machined from heat-treated chromoly and then chrome plated, these seriously tough cogs are strong, shiny and they come in sizes from 13T to 22T so you can pick the perfect gear.