Like all things that get used a lot, your bike is liable to wear and tear.
All those miles in the saddle serve to slowly but surely wear down key parts of the bicycle, particularly the cassette and chain.
Dirt, salt and grit from the road kicks up into the bike’s drivetrain and rubs into the metal components and wears them out. The teeth of cassettes become rounded, chains get ground down, and things stop functioning as they should.
It’s not always possible to detect this is happening as you ride along, until all of a sudden, the bike stops changing gear correctly, you hear ticking and clicking, and the chain jumps from one sprocket of the cassette to another.
While a bike is still rideable in this state, it’s far safer, faster and more fun to prevent it from happening!
To do this, the key is to keep your bike as clean and well-maintained as possible to slow down the rate of wear, but also to replace items before they get totally worn out.
There’s no specific rule regarding timeframe or distance travelled. Someone riding 100km every day on dry, clean roads may find their chain lasts better than someone cycling 100km per week but on filthy mucky roads.
The key to catching your chain before it becomes totally worn out is to check it regularly for ‘stretch.’ There are various very simple tools to help with this, and which provide a guide as to when the chain is nearing the end of its life, and when it’s time to get a new one, fast!
It’s best to not let your chain become too worn before you replace it, as riding a ‘stretched’ chain for too long will speed the deterioration of your cassette – a component which is many times more expensive to replace.
Like changing a chain, there is no distance or time threshold for a cassette – it all depends on how much wear and tear it gets.
The easiest way to know when it’s time to change the cassette is by inspecting the teeth on the sprockets. These should ideally be ‘square’ rather than sharp and pointy.
Once the teeth start becoming rounded or pointy, the chain will stop sitting as cleanly on the cassette sprockets. Gears will jump and skip, and changing from one sprocket to another becomes less clean and crisp. All of which means its new cassette o’clock!
When you change your cassette, it’s typically advised that you change the chain at the same time. A fresh cassette with not run a beaten-up old chain as smoothly as it should, and the worn chain will rapidly grind down your cassette and shorten its life.