Equipped with the correct size cogs to meet the governing body of cycling's gear restrictions, which protect Junior racers from knee injuries, the Ultegra 10-Speed Junior Cassette features Shimano's ultra-smooth shifting and excellent durability, too.
Note: 10-speed cassettes require the use of a 10-speed chain.
The Ultegra 10-speed Cassette is compatible with 9-speed hubs with the use of an included spacer.
Note: The large outer cogs of these cassettes may not be compatible with all frames. Do not ride without testing for clearance.