
Decathlon's cycling brand offers handy tips to help with your cycling practice.
Whether you opt for a freewheel or cassette will depend on the make and model of your bike (some newer bikes are only compatible with a cassette, for example, but that will be apparent when you make your purchase/take a closer look) and what you use your bike for. Plus you’ll need to know about the rules of replacing each one.
To make the right choice, you need to know the difference between a freewheel and a cassette, so let’s recap.
The Freewheel
The freewheel is a block of cogs that screws directly onto the wheel.
The Cassette
On a cassette, the cogs slot one by one onto the cassette body. They are then held in place with a nut.
Pros And Cons
A freewheel is trickier to remove or change and has less gears, so is better suited to casual riders who prefer taking things a bit slower and sticking to the streets. In contrast, a cassette is easier to change and much lighter, making it ideal for two-wheeling adventurers who want to pick up the pace, try a variety of terrains and speeds and are more likely to update/replace parts.
If you choose a freewheel, you’ll have to stick with a freewheel and if you choose a cassette - yep, you’ve guessed it - you’ll have to stick with a cassette. It’s difficult and costly to swap. Furthermore, you’ll need to make sure your shiny new freewheel/cassette has the same number of speeds as the original.

Nicolas
Cycling Specialist
Remember to grease your drivetrain regularly to keep everything running smoothly.
Also, change the chain each time you change the cassette - if you use new cogs with a worn chain, it will jump and won't hook on properly. The opposite (changing the cassette when you change the chain) depends on how worn it is.
To be on the safe side, always change both at the same time