
What are bike cassettes?
A bike cassette is the cluster of sprockets (gears) mounted on the rear wheel hub of a bicycle.
Bike cassettes are part of the drivetrain and work with the chain, derailleur and crankset to control your bike’s gearing.
- Location: On the rear wheel hub.
- Function: Lets you shift gears to make pedalling easier or harder, depending on terrain.
- Works with: The chain and rear derailleur.
Bike cassettes come in different sizes (e.g. 11-28T, 11-32T), where the numbers refer to the number of teeth on the smallest and largest sprockets, respectively.
More teeth = easier pedalling.
A good bike cassette improves your riding efficiency, especially on hills or during sprints.
Road bikes, mountain bikes and e-bikes often use different cassette types depending on the terrain and riding style.
Important:
Make sure your bike cassette, bike shifter and chain are compatible; meaning, they are designed for the same number of gears.
For example: a 11-speed chain and 11-speed bike cassette.

Bike cassette brands
Cassettes are brand-specific in terms of spacing and design. Common brands:
- Shimano and SRAM: Often interchangeable for 8, 9, 10-speed, but not always for 11 or 12-speed.
- Campagnolo: Not compatible with Shimano/SRAM.
- microSHIFT is a relatively new player but they are dominating the mid-range market with their super robust products and great value.

Speed (Number of Gears)
You need a bike cassette that matches the number of rear gears (speeds) your shifter, chain and derailleur are designed for.
- 8-speed cassette must match an 8-speed shifter
- 10-speed cassette must match an 10-speed shifter
The spacing between sprockets is different for each speed, so mixing won’t work properly.
A note on spacing:
More speeds, means there's less space between each gear. Less space delivers a smoother (and faster) gear shift.
That's because the chain doesn't need to move across as much before being picked up by the sprocket.

Freehub Body Compatibility
The freehub (the part of the hub that the bike cassette slides onto) must match the cassette:
- Shimano and SRAM HG freehub fits most 8–11 speed cassettes.
- SRAM XD and XDR for their 11/12-speed cassettes.
- Shimano MicroSpline is needed for newer Shimano 12-speed MTB cassettes.
- Campagnolo cassettes only fit Campagnolo freehub bodies.
The HG style freehub is the most popular. It has 9 or 10 splines and the bike cassette slides onto the freehub body and uses a lockring on the end of the cassette to lock it in place.
SRAM designed the XD (for mountain bikes) and XDR (road and gravel bikes) cassettes for their high-performance bikes.
These are not interchangeable. However, an XD cassette will fit onto an XDR freehub body - with a 1.85mm spacer behind the bike cassette.
XD and XDR bike cassettes thread onto the freehub and don't slide on.
Shimano designed MicroSpline for performance mountain bikes. MicroSpline (MS) freehubs use lots of small splines to lock the bike cassette into position.