Different methods for knowing when you need to change the chain on your bike.
1. Finger Test
- A simple test is to use your finger and try to lift the chain away from the chainring. If the chain can be pushed quite a bit away from the chainring (like above), this is a sign that the chain needs changing.
- For this test, I put it biggest gear (biggest front chain ring, smallest rear cassette, e.g. 53*13)
If the chain is badly worn, you will probably need to change the cassette block at the same time. (and possibly front chain ring)
2. Chain Measuring Tool
You can also buy a chain measuring tool which will tell you how worn a chain is. Such as this Lifeline Chain measuring tool for £6.00 from wiggle
3. Measure with Rule.
Put a tape measure a the centre of a chain pin. At 12 inches, a new chain will be exactly at the centre of a pin. If the centre of that pin is 1/8 past the 12inches, the chain needs changing.
- If the centre of the rivet is less than 1/16? past the mark, your chain is ok.
- If it’s between 1/16? and 1/8? past the mark you’ll likely need a new chain, but your cassette should be ok.
- If it’s more than 1/8? past the mark, you’ll probably have to replace both the chain and cassette.
Chain on My Commuting Bike.
With my commuting bike, I usually wait until the chain starts to slip and then change the chain, cassette block and front chainring altogether. It means that it can be 1 or 2 years between changing the chain. Towards the end of the chain cycle, it is probably becoming inefficient. But, the hassle of changing it is greater than the decrease in inefficiency. However, if it starts slipping, it is definitely a sign it needs to be changed.
Recently, I kept putting off changing the chain on my commuting bike and really notice the difference now I did it at the weekend. I wish I had done it earlier because it makes a much more pleasant ride.
Time Trial Bike / Road Bike
On my road bike and time trial bike I have a Dura Ace groupset, and so want to try and
- Extend the life of the cassette blocks
- Not lose any inefficiency in the drive mechanism.
Therefore, I will try and change the chain quite frequently, before it needs replacing. This is because a worn chain can lose efficiency in the drive mechanism; therefore, for optimal performance it is worth changing frequently – perhaps every 1,000 miles. This means you can use a couple of chains per cassette block.
Note I prefer to replace with a cheap chain frequently than replace with Dura Ace infrequently. Also when replacing the block I tend to go for Shimano Ultegra. The price is about 50% of Dura Ace and only a slight difference in performance.
Tip: Keep a record of when you change a chain and note the mileage. This will give you a guide to when you need to change the chain.
- Chains for road bikes at Wiggle
- Rear cassette replacement
- Correct chain length for bike
- Chains and drivetrains at Wiggle Cycles
- How to spot Worn cassettes and worn chainrings