Last week we wrote about the magic of the humble barrel adjuster. I asked if bike maintenance articles that provide big wins for cyclists, but are extremely accessible for beginners is something you’d like more of. The answer was overwhelmingly yes.

This week therefore, I want to share with you a £5 tool, that can save you £30 or more every year you use it.

That humble little £5 tool, is the Chain Wear Tool, which looks a little like this:

What does this magical tool do?

Well, you see, every mile you pedal, every hill you climb, every car you overtake in the morning rush hour, slowly wears away at your bicycle chain.

Generally, you’ll need to replace the bicycle chain 1 to 3 times per year, depending on the riding you do.

However….

If you don’t replace the chain, and you keep riding with a worn out chain, then you end up wearing out your cassette.

This grimey old thing:

Bummer dude – as a surfer would say upon seeing no waves today.

So how does one avoid this eventuality?

One must know when to replace ones chain.

How?

As the instructions in our ever wonderful Bike Doctor app (download it, support London Cyclist!) will tell you:

Get your chain wear tool Drop the one end with a hook in to your chain If the other end marked 0.75, drops right through, then your chain is worn If the 1.0 end drops through, then you also need to replace your cassette – sad face

(In the picture above, it’s almost time to replace the chain)

You can normally replace your chain 2-3 times, before you also need to replace your cassette.

A chain replacement is about £10-£15. A cassette replacement is £30-£50. Depending on whether you do it yourself, or get a shop to help you.

Save your cassette – know when to replace your chain!

Before you die hard bike maintenance nuts jump in on the comments and say:

“Hey Andreas! You don’t even need a chain wear tool, you can just work it out yourself”.

It is 100% true my friend. If you want to save £5 and work it out yourself, here is how you do that. Personally, I prefer a chain wear tool which will instantly tell me if it’s time.

Want more bicycle maintenance goodness? Learn about the barrel adjuster: