A bike chain is what brings the whole drivetrain system together. It’s the most important mechanical part of the bike, and you wouldn’t get very far without one.
What’s special about a bike chain is that not only does it need to be incredibly strong, but it also has to be incredibly flexible.
Different bike components are worn in different ways, and it’s important to understand how they wear to look after your bike properly. A question many cyclists often ask us is, “Do Bike Chains Stretch?”.
In this article, we’re going to be discussing just that.
- Understanding Bike Chains
- Do Bike Chains Stretch?
- What Causes Chain Stretch?
- How Do You Prolong Chain Stretch?
Understanding Bike Chains
Bike chains are very important and are much more complex than you might think. They link the cassette and chainrings together and run through both the derailleurs.
Chains are made to be very strong, but they also need to be flexible enough to run up and down the gears and work at multiple different angles. If you look at the chain on a bike, it isn’t fixed in one place and can move around freely with your control.
Chains come in different shapes and sizes and come in different lengths and widths to suit different speeds and drivetrains. When put on a bike, they typically need to be cut to length and then a master link installed.
Do Bike Chains Stretch?
Yes, bike chains do stretch. When power is applied to the pedals, a lot of pressure is put on the chain. This does, in time, makes the chain stretch out and can, in time, affect the bike’s performance.
The links slowly stretch out, and the chain becomes more relaxed under pressure. This leads to sloppy shifting, possible breaks, and even extra wear on other components, such as the cassette and the chainrings.
How Do I Measure Chain Stretch?
Chain stretch can be measured properly using a special chain checker tool. These are small metal guides that you put into your chain, and they can tell you when it is stretched 0.75 mm or 1 mm.
0.75mm is when most companies recommend getting the chain changed. 1 mm is when it’s well past its due date and will need changing as soon as possible as there’s a risk it could break.
The difference between the stretch on a new chain and a used chain is huge. If you don’t have a checker, you can tell by pulling a couple of the links on the front of the chainring, and if it moves more than 1-2 mm, then your chain is stretched.
What Causes Chain Stretch?
There are many causes of chain stretch, and knowing them can help you avoid it happening in the future. Here are the most common causes.
Manufacturers recommend that you change your chain every 1500 miles, and that’s if you are tame and riding in good conditions. The more powerful a rider you are, the quicker chains can wear out.
Not Being Used Correctly
If you don’t use the chain correctly, you can expect a much shorter life. Hammering on the pedals and not letting off the power while changing gears is an easy way to destroy a chain quickly.
Riding In Poor Conditions
Riding in poor conditions is a very easy way to stretch a chain quickly. When dirt starts to get on the chain and in between these links, it causes it to stretch very quickly. If you want to stretch a chain really quickly, ride on a beach often.
If you ride a chain without oil, you are not going to have a great experience. Not only will you lose performance, but you will also get a lot of chain noise and stretch your chain incredibly quickly.
How Do You Prolong Bike Chain Stretch?
You can’t avoid chain stretch altogether but can easily prolong it if you look after your chain correctly. Here’s what you need to know.
Regular Cleaning And Lubrication
Not only does it help it run much smoother, but it also stops dirt from stretching everything out. It’s a good idea to use dry lube in summer and wet lube in winter too.
Use Proper Shifting Technique
When using bike gears, it’s important to be smooth and, when changing, to let off the power a little bit. When switching from cog to cog, your chain is much more vulnerable. If you power through, it will stretch your chain quickly.
If you keep on top of your cassette, chainrings, and keep the correct chain tension, then your chain will last longer. If you neglect maintenance, then expect breakdowns and a poor ride when out on the roads or trails.
Avoid Extreme Conditions
Riding in extreme conditions is another way to cause quick chain stretch. Chains are not as good in sandy conditions, snow, extreme heat, and cold. Riding them like this wears them down very quickly.
Proper Installation And Use
Chains need to be the correct length and be at the correction tension, if not, they don’t live a very long life. Ensure that everything is installed properly and the tension is correct, and you will get a lot more miles before the next change.
A Final Note
Chain stretch is the main reason why you are going to need to replace a chain. It’s unavoidable, but you can slow it down by properly using and looking after your chain.
We highly recommend investing in a chain checker to check for stretch, some good quality chain lubrication, and also a decent cleaning kit.
Robbie Ferri has spent years working in a bike shop, has worked with industry leading brands on product creation, has been a semi pro athlete, and is a fully qualified strength and conditioning coach. He has broken World Records, bikepacked all over the World and raced ultra distance at a top-level.