Looking after your bike chain is a sure way to prolong both the chain and the whole drivetrains’ life. Your chain is put under a lot of pressure and exposed to the elements throughout the year.

Every time you spin the pedals, you rely on your chain to convert your leg power into the rear wheel’s rotations. This constant pressure does result in your bike chain stretching.

Yes, your bike chain will stretch

Depending on use, how well you look after, and the chain’s quality will dictate how long it takes your chain to get worn (or stretch).

As a general rule of thumb, just a 1% increase to the standard 0.5in (12.7mm) pitch (or the space between each pin) means that your chain has stretched and needs replacing. 

Why is it essential to monitor chain stretch?

Although bicycles are simple, they are very efficient machines. Your drivetrain (front chainring and rear cassette specifically) is designed to fit the pitch of a chain perfectly.

A small deviation and you lose power, risk the chain slipping or skipping gears and the longer it goes untreated ruining your cogs altogether.

When your chain is stretched, you will start to notice the teeth on the cogs slowly getting shorn away, making them a lot more pointed than they should be. This is what leads to your chain slipping and skipping of gears. 

By replacing your chain before it starts causing damage to your other components, you can save yourself hundreds of dollars. So as part of your bicycle maintenance routine, after cleaning and applying chain lube to your chain, you should measure it. 

How do you measure chain stretch?

You can either buy yourself a relatively inexpensive chain checker tool, which simply slots into the gaps between the chain links at two specific points, and if it’s not a snug fit, you know that the chain is worn.

Most will have a form of measurement on the side, so it is a little bit more scientific than just stick in and make a call. 

Alternatively, you could just use a ruler. 12 chain links from pin to pin should be exactly 12 inches. If it is any more than 1% more than that, you need to replace your chain before it causes irreparable damage to your chainring and cassette. 

Recommended Replacement Chains

Conclusion

Keeping your bike maintained many times means a lot more than just keeping it clean! While it doesn’t happen super often, replacing your bike because it has “stretched” is definitely a thing.

Stay safe, and maintain your bike!