SRAM PG850 8 Speed Cassette

What are cassettes?

A bike cassette is the cluster of rear gear cogs attached to the rear wheel.

Who needs a cassette?

Any conventional derailleur-geared bike has a cassette, whether it’s a road bike, a mountain bike or a hybrid. The alternatives are a singlespeed or a hub gear on the rear wheel.

What are the choices?

The main difference between cassettes is the number and size of gear cogs on them. Seven, eight, nine, 10 and 11-speed are the most common.

What should I buy with them?

If you’re replacing your cassette, sometimes you have to replace other parts of your drive train such as your chain or chainrings. This is because they wear evenly together.

Anything else?

With some cassettes you don’t need to replace the whole unit. Instead, just part of the cluster is detachable, so you only swap out the most worn cogs.