How to Shorten a Bike Chain (Updated 2020)

*Please note that this post may have affiliate links. By clicking on them, we may get a small commission on any sale.

With more than half the world’s population in some form of lockdown, most of us have had to find things to do. Lots of people are taking out their bikes and doing all the fixes.

Some tasks are easy, like cleaning and oiling the chain. But how to shorten a bike chain? Before we talk about that, it may be important to take a minute to talk about why you should make sure that your bike works well, especially at this time.

When lockdowns are eventually lifted, I imagine that at least for some time, people will want to avoid public transportation.

It’s often crowded, and as we know, even if a Coronavirus vaccine is rolled out, it will be some time before everyone in the population has taken the necessary protective measures. For a while to come, if we go by experts’ predictions and our own common sense, it will be best to continue to keep some distance between ourselves and others.

If you don’t have a car, or is your commute isn’t very long, it will make sense to use a bike. You’ll be able to get some fresh air and exercise every day.

Why Shorten a Bike Chain?

All bikes come with a recommended bike chain length. It’s important to stick to this length if you want to ride comfortably and preserve the life of the rear derailleur.

It’s the bike chain that does the work of getting the tires in rotation so that your bike can get in motion. If the chain doesn’t fit right, getting your bike to move properly will be an uphill task. There are a couple of simple reasons you may need to resize a bike chain.

  • The first is when you buy a replacement only to discover that it isn’t an exact fit.
  • The other common reason for shortening a bike chain is that over time, as a chain ages, the links stretch and slip and you’ll never get your bike to run.

If you are not a DIY inclined person and you notice that the chain on your bike doesn’t fit, your first impulse may be to seek out a professional who can shorten it for you, or to ditch the bike altogether and buy a new one that comes with everything fitted just right. There is no need for drastic action just yet. So long as you have the right tools and a bit of time you can shorten a bike chain yourself.

In this post, I will tell you how to shorten a bike chain with a chain tool and how to shorten a bike chain without a chain tool. I will also look at how to shorten a chain for a mountain bike.

How ro shorten a bike chain

#1. How to Shorten a Bike Chain with a Chain Tool

The first thing you need to do is make sure that your bike chain does indeed need shortening. The best way to do this is by taking some measurements.

Measure, from tip to tip, 12 links. If your chain is the right length you should get about 12 inches or just a little more. Any longer is an indication that your chain is a little old and pins are worn, which has made the chain longer.

You may measure the 12 links and find that the length is just right but you still have a bit of slack. You can fix this by loosening the back tire and pulling it back a fraction of an inch and then tightening it again. This ought to take up the slack and fix the problem.

So, let’s assume that you measure the links and find that they are longer than they should be. Here is what you should do:

  • Once you have a chain tool the next step is to put your bike up on a stand. If you don’t have a stand, lean it against a wall and make sure that there is enough room to move the tires around so that the chain can move easily.

Now it’s time to clean the bike chain. I have written a detailed post about How to Clean a Bike Chain and why you should clean it. When you are shortening a bike chain it’s a good idea to clean it first so that once you’re done the bike is ready to lube and go. The post also tells you what you can use to get your bike chain clean in minutes.

  • After your chain is clean, locate the master link. You can tell it apart from the rest because it is often darker in color. It may also be covered by a plate with a couple of pins protruding from it.
  • Some chains do not have a master link. Check yours all round. If you don’t find a link that’s darker than the rest or that’s covered by a plate it means that you need to use the chain tool to break the chain so that you can remove some links.
  • Place the master link between the front and back gears for easy reach. Loosen the master link and keep it somewhere safe.

You may want to see what your bike documentation has to say about the master link. Different types of master links require different methods of removal. With some, all you need to do is push out the pin, but some require removal with a pair of pliers. If your bike has the latter, you will need to replace the master link as it gets destroyed in the process.

  • Now it’s time to shorten the chain. Based on what measurements you got when you measured the chain, you’ll decide how many links you need to remove. My advice is always to take off a few links at a time and keep going until you get the right length.
  • To remove a link, you will use the chain tool. Your tool comes with instructions about how to use it to remove links. Follow them to the letter, and if you bought a quality tool you should be successful.
  • If you’ve never done it before, you may find removing the first link a little challenging, but after you do that one the rest will be a breeze. Remove all the links that need to go, but don’t throw them away yet; you may still need to reattach one or two.

Now it’s time to reassemble the chain. This step is easy. Using the chain tool, attach the two ends of the chain to the master link and push the pin in until you hear it click. If you had to replace the master link, attach it to one end of the chain and then attach the other end and push the pin into place.

When done, the bike chain link will be shorter and your bike will ride comfortably once more.

*Learn How to Tighten a Bike Chain

How to shorten a bike chain

#2. How to Shorten a Bike Chain Without a Chain Tool

The steps here are the same, except that instead of using a chain tool, you’ll use a small nail, a hammer and a pair of pliers. You will also need a small clamp to hold the chain in place.

  • You should elevate your bike on a stand or lean it against a wall. Locate the master link and remove it.
  • Take a section of the link and decide how many links you would like to remove. Remember, it’s better to remove too few than too many. Putting them back in is an extra headache.
  • Detach the chain from the master link and then hold the loose link in place with a clamp. Make sure you can reach the pin to be able to remove it using a small nail and pliers.
  • To do this, place the nail on the pin and hit it gently using a pair of pliers until it pushes out on the opposite side. Repeat this process until all the links you want to remove are out.
  • To reattach, place the master link on both ends of the chain and push them in using a screwdriver until you hear them click into place.

Check your chain to make sure that it’s the right fit.

How to Shorten a Mountain Bike Chain

MTB chains may seem a little more complicated than chains on regular bikes because they come with additional units. They are not; the process to shorten a chain on an MTB is similar to what we have described here.

You need to mount the bike, clean the chain and then if you have a chain tool, use it to remove extra links. If you don’t have a chain tool use a small nail and a pair of pliers to get the pins out of the links. Once you have the right length, make sure that the chain is properly reattached. Lubricate and put the chain back on.

It is important to mention that different types of mountain bikes may require different methods to remove extra links. If you ride one that’s made for active sport it may come with a slightly more complex link mechanism.

Check your user manual for directions on how to remove extra links.

Most high-end bikes (mountain and others) come with detailed user manuals that take you through a step-by-step process for simple things like how to shorten a bike chain.

Important TipsHow to Shorten a Bike Chain

  • Make sure that you apply high-quality lubricant to your chain before you re-mount it. Lubricant is the most important thing to a bike chain, and I have written about benefits and different types of lubricants here.

I’ve discussed how you can shorten a bike chain without a chain tool, but this isn’t recommended if you are a frequent rider. If you use your bike often you’ll need to adjust the bike chain regularly and having a chain tool is best if you want to get the task done fast and efficiently. You should buy a high-quality chain tool and pack it along with the rest of your bike tools.

  • Even if your bike chain doesn’t feel slack it could have suffered damage that isn’t very obvious and you may eventually break down when out riding. I recommend that you check your chain every few months if you don’t ride every day, and every few weeks if you do.
  • Make sure that you lube your chain frequently to prevent wear and tear and make sure your bike rides well.
  • If you have a very expensive bike you may not want to do this kind of maintenance yourself. If you aren’t DIY-savvy, you may damage it and invalidate the warranty. It’s best to find a repair shop that has experience with your specific brand and let them do regular maintenance.

Conclusion

Bike chains can lengthen due to age and use, or you may buy one that’s too long. With a few tools, a bike stand and a little time you can remove extra links, shorten the chain and make your bike rideable once again.

Learning how to tighten a bike chain is important. It is a simple process and you don’t really need to pay a third party to do it for you.

Of course, not everyone is inclined to do this kind of maintenance for themselves. If you don’t want to get your hands dirty or don’t have the time, your local bike mechanic can do it for you for a few dollars.