The cassette determines the range of gears available to you. Shimano, SRAM, Campagnolo and Miche now cover 10-, 11- and 12-speed systems, with large sprockets commonly reaching 34 or 36 teeth.
Which freehub body for my wheel?
This is the first criterion, and the one most often overlooked: it is your wheel that determines the standard, not your drivetrain.
Shimano HG : 8- to 11-speed cassettes, the historic standard.
SRAM XDR : SRAM cassettes starting with a 10-tooth sprocket.
Campagnolo N3W : recent 12- and 13-speed Campagnolo cassettes.
Which gearing for my terrain?
11-28 or 11-30 : regular tooth jumps, ideal for flat and rolling terrain.
11-34, 10-36 : wide range for mountains and long distances.
Close ratios preserve cadence, while a wide range saves your legs.
Will my derailleur accept this cassette?
Each rear derailleur specifies a maximum compatible sprocket : exceeding it causes rubbing and imprecise shifting.
The number of speeds must match that of your shifters.
With an electronic drivetrain (Di2, AXS), stick to combinations approved by the manufacturer.
When should it be replaced?
Chain skipping despite a properly adjusted derailleur and rounded teeth indicate a cassette at the end of its life. Replace the chain and cassette together: a new chain skips on a worn cassette, and a new cassette wears out very quickly behind a worn chain.
