How To Spot Chain Wear and What To Do About It

As an urban cyclist there are some things which just drive you crazy; dogs not on leads, cars parked in bike lanes, pot holes, bike lanes which end when you most need them, bendy buses and forgetting your gloves, to name but a few. When so much feels to be out of your control it’s important to take charge of the things which are within your control.

For all of us the nature of regular cycling is that our bike’s components sooner or later start to show signs of wear and tear often resulting in functionality which is less than perfect. We shouldn’t be surprised by this, in fact we should be encouraged by this, it shows we’re using our bikes for the purpose for which they were designed, which is but another way of saying we’re investing in our health, our productivity and our general well being. Good stuff, keep it up! A bike showing few signs of wear is simply an occasional  cyclist rapidly becoming less productive, less healthy and less well. 

Worn parts such as the chain and cassette can however make for an extremely frustrating ride. Gear selection becomes more and more problematic, the chain slips under strain and the whole cycling experience soon begins to resemble one almighty mass of frustration. You deserve much better so it’s important we help you to get on top of this situation. 

Firstly a little about the origins of your problem.

Your bike chain is a series of connected links between which there is an airgap perfectly sized to house the teeth of your sprocket and chain ring. Every time you pedal those links are placed under significant strain and invariably "stretch". At first this stretch is almost microscopic but over a culmination of many thousands of revolutions that stretch adds up. In time the once perfect measurement gives way to links moving into spaces originally devoted to sprocket teeth, meaning that your chains rivet housing is now grinding along your sprockets teeth. If it feels difficult to change gear that's because your chain literally has no where to go. 

Step 0

Stop asking "When should I change my chain" and begin to develop a method. 

Step 1

Reach for a chain checker on a regular basis. This tool has two fixed measurements one on either side 0.5mm and 0.75mm respectively. It is one of the simplest but most useful of all tools. On the 0.5mm side hook one end over a chain link and then set the tool on top of the chain.


Step 2

If the tool sits inside the links then your chain is stretched and needs to be replaced. In ordinary circumstances, and if you're catching chain stretch eary you should look to change your casette every third chain. 

Step 3

Flick the tool to 0.75mm and if it still fits then your worn chain will have significantly worn down your sprockets too. You should look to change both

NB: Trying to scrimp at this point is a very bad move. Your warn down cassette will soon be playing havoc with your new chain.

Things You’ll Need

If you’re confident and ready to do this job yourself you’ll need a chain checker, a new replacement chain (like for like) a chain breaker, some decent lube, time and patience. 

If you’d like us to replace your chain then just bring your bike over to the pod and we’ll only charge you for the price of parts. If you opt for a Silver Service or Winter Service a new chain is all part of the deal. 

NB: A significant number of our customers now know exactly when their next chain replacement is due and book in every three to four months meaning there is never any real need to change their cassette. While its bad for our business its good for your bank balance to do likewise. 

A Few Important Warnings

If you’re lucky enough to be riding a nice high end group set don’t be tempted to scrimp on a cheap chain. 

If your chain and cassette show signs of very significant wear then you ought to bear in mind that you may also have damaged your front chain ring. An experienced mechanic will be able to guide you further. 

With your old chain off now is a good time to clean the cassette and jockey wheels

If you ride a belt drive bike, put your feet up, relax and enjoy a warm feeling of complete smugness.