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How to Shorten a Bike Chain
in 3 Easy Steps

How to Shorten a Bike Chain
New bike chains have to be the right length for your bike to allow safe riding. A lot of people take their replacement chains to a bike mechanic but that isn't necessary. In this blog post, we're going to take a look at how to shorten a bike chain on your own! 

Note: Bike chains tend to stretch with wear but you really shouldn't shorten the chain as a ‘fix’. Instead, simply replace it when it has stretched beyond the maximum recommended amount. This blog post only focuses on shortening replacement bike chains that are too long.

1. How to Remove the Old Chain

Check whether the chain needs to be replaced

If you notice some slack on your bike's chain, remove it and lay the chain out on a flat surface. Mark out 12 links on the chain and measure the distance from that first pin to the last one. If the length exceeds 30.80 cm then you'll need to replace the chain.

Raise the Bike

Mounting the bike on a bike stand makes it easier to remove the bike chain. Not only does it hold the bike in place, making things way more convenient for you but it also keeps the tyres elevated. This makes it easier to rotate them when you're testing out the replacement chain.

If you don't have a bike stand, then the next best thing is to lean the bike up against a wall. Make sure to tip it over so that the wheels are on the top.

old bike chain

Remove the Chain

To start with, remove any dirt or grease from the chain using bike chain cleaner or isopropyl alcohol. This will allow you to identify the master link more easily. 

A master link is a single removable link that allows you to disconnect the chain from the bike without having to use a chain tool. Think of it as the clasp on a necklace. The master link stands out from the other links because it's typically darker or lighter. That's why it's so important to clean the chain in the first place. 

Other than that, you can identify a master link by its special outer plate.

Note: this post covers how to shorten a bike chain without a chain tool.

Once you've located the master link, slowly rotate the pedals on your bike until the link arrives between the front and back gears. 

This will ensure that you can access it very easily.

There are different ways to remove the master link and the method you should employ varies with the type of link. For instance, with some, you slide out the pin by swiveling. Some master links are disposable, meaning you can only remove them by breaking or bending them. You can find out what type of master link you're dealing with by visiting the manufacture's website. The chain's model will typically be engraved on its side.

2. How to cut a Bike Chain’s Length

Let’s take a look at how to take apart bike chains so you can shorten them. Here are the steps:

Thread the Replacement Chain

Ideally, you want to shorten your replacement chain after threading it through the chainrings and cassette. This makes it easier to determine how long your chain needs to be. 

Before threading the chain, however, check whether there are signs of extreme wear on the chainrings and cassette on your bike. Take a close look and check whether the profiles are symmetrical. When they're extremely worn down, they can take a pointed appearance. If everything looks okay, proceed to clean out the chainrings and cassette, getting rid of any dirt and grease.

Remove the Links

We recommend removing one link at a time so you don't have to go through the trouble of adding them back on if you make the link too short. Here's an easy step-by-step guide on how to take links off a bike chain:

1) Start at the end of the chain which doesn't contain the master link. Hold the terminal link in place using the clamping mechanism on it. If your chain doesn't have a master link, then you can start at any end.

2) Place the punch present on the chain tool over the master link's pin. Rotate the tool clockwise slowly until the pin is pushed clear of the outer plate but don't go as far as to detach it from the link. In case you do push out the pin completely, you may need to replace it (if you intend to use it again in the future).

3) Do the same for the other pin on the master link, pushing it out just far enough so that can you can remove the outer place and the piece that attaches it to the adjacent link on the chain.

4) Remove as many links as necessary. In most cases, you wouldn't need to remove more than five links from the chain. 

Store the ones that were removed in a safe place so that you could use them for any repairs in the future.

And that’s all about how to take links out of a chain.

3. How to put a Bike Chain back together

Earlier, you learned how to disassemble bike chains to shorten them. Now let’s look at how we can reassemble a chain:

Connect the master link to the two ends of the chain

You may have to use a chain tool for this, depending on what type of master link you're dealing with. If your chain comes with a disposable master link and you had to destroy or bend it to break up the ends, then you'll need to replace it.

Connect the ends using a chain tool

Bring the two terminal links together, ensuring that their pins are facing in the direction of the chain tool's pin. Start turning the tool in the counterclockwise direction slowly and keep going until you see the chain pin protruding a bit from the other side of the link. Ideally, each pin should be protruding the same length on both sides.
stainless steel bike chain

Lubricate the chain

Lubrication is an effective way to increase your replacement chain's lifespan. It will reduce wear and improve shifting performance if you have a bike with gears. 

And that’s all there is to it! In this blog post, you learned how to remove a chain, how to take links off a bike chain to shorten it, and how to reassemble it. Now, you’ll never have to go to a mechanic for something so simple.

Frequently Asked Questions

What happens if my bike chain is too long?

If the chain is too long it's a lot of slack and severely impacts shifting performance.

What happens if the bike chain is too short?

On the other hand, if the chain is too short, it can lead to even bigger problems. Typically, the bike won't be able to shift into the largest cog which isn't even the worst-case scenario. If it does shift, it can cause the derailleur to come off or bend the gear teeth. 

To sum it up, if the chain is too long it could inconvenience you. However, if the chain is too short, it can end up ruining your bike. That's why it's very important to remove links one at a time so that you don’t shorten the chain more than needed.

How to remove a bike chain without a master link?

If there isn't a master link on the chain, you can start with any other link. Using a chain tool, push out the pins on that link but make sure they don't completely detach. Afterward, gently twist the chain and it should come off.

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