Heres How to Fit a Bicycle Chain

When it comes to caring for your bicycle, there are a few essential skills you’ll need to become proficient at, including airing tires, changing or adjusting seats, and how to fit a bicycle chain. Chains are a consumable part of the drivetrain, and constant or long-term use causes that chain to wear and stretch as you go. This means that there will come a time that you need to replace the chain in order for your bicycle to steer and shift properly.

Luckily, whether you have a road bicycle or a mountain bike, the steps required to change and fit a bicycle chain are the same. With proper instructions, anyone can do it, and as you spend more time with your bike and have to make these adjustments and changes frequently, it’ll grow easier and more natural. You should always start by gathering all your tools and anything you need for safety purposes so that you don’t get caught off guard lacking something in the middle of your project.

Measuring for Wear

How do you know if you need to replace your bike chain? You can measure it for wear by looking for deformed sprocket teeth, mis-shifting, and skipping. There are also special tools you can use to determine if the chain is too worn to continue using it. Another option is to measure 12 complete links. If the section measures 304.8mm or longer, it’s time to replace the chain, as this shows too much stretch and wear. You may also be at a point of needing to replace the cassette, depending on just how far the existing chain has stretched.

What You Need

As with any task related to mechanics, there are a few tools you’ll want to gather in advance of fitting your bicycle chain.

  • Chain breaker (or chain splitter tool, as some call it)
  • A piece of a broken spoke
  • Quick link pliers
  • The appropriate speed chain

Note that, by design, bike chains are interchangeable across manufacturers, for the most part. However, you will not be able to fit a 10-speed chain to a 9-speed bicycle. You’ll want to assure that you get the proper speed chain before you try to install it on your bike.

Removing the Old Chain

Before you can fit the new bike chain, you have to first remove the existing one. Be sure you’re prepared, since you’ll be working with a chain and other items that could cause injury.

  1. Use the chain splitter to push one of the pins out of the bottom, or lower, stretch of chain, or you can undo the quick link, if there is one installed on the chain.
  2. Once you have the pin removed, you can carefully remove the chain from the bike with little effort.
  3. Inspect the cassette for wear. If you’ve been riding the existing chain too long and worn it too far down, you may find that the cassette needs to be replaced as well. If it is in good shape, you’re ready to fit the new bicycle chain in place.

Fitting the New Chain

Before you can put on the new bike chain, you’ll need to make some adjustments on your bicycle.

  1. Using the gear shifts, set the rear derailleur to the biggest cog.
  2. Repeat this for the front, setting it to the largest chain ring.
  3. Next, release any clutch mechanism you may have on the rear derailleur.

Now, it’s time to set to work on the chain itself.

  1. Start by threading the end of the chain through the front derailleur.
  2. Turn the crank. You want to have a few inches dangling under, so you can then place the other end of the chain in the seatstay, then lay it across the cassette.
  3. Pull down on the rear derailleur.
  4. Next, thread the chain over the top of the upper jockey wheel.
  5. From there, thread it behind the tab in the derailleur cage arm.
  6. Continue threading by taking the chain through the lower jockey wheel
  7. Finally, send it through the lower tab of the derailleur cage arm.
  8. At this point, you can release the derailleur. Do this gently to avoid damage to the chain or bike and to assure the chain doesn’t fall off.

Now, it’s time to actually fit the chain and assure it’s going to function properly.

Sizing the Chain

In order to make sure the chain operates no matter what gear you use without damaging the bicycle, you’ll need to size it properly. In order to do that correctly, you’ll have to adjust the chain so that it is fitted to the two largest rings – the one in the front and the one in the rear. Take note that you should never ride in this gear.

  1. Once you have the chain in place, pull the two ends towards each other. Measure which to split by holding them in place where they meet. Having a broken spoke handy is the perfect way to keep the chain taut and in position.
  2. There are two possibilities for the next step – for a Shimano chain, you need to have an inner and outer plate at the end of the chain, while a SRAM or KMC chain needs two inner plates at each end of the chain. Make the determination before you continue your effort.
  3. When the chain is the right length – with some movement to the derailleur arm – you can split the chain using the chain tool.
  4. Shift the gears manually to move the chain to the smallest cogs.

There are a few caveats to keep in mind. For full suspension mountain bikes, check the chain length, as that could change depending on whether or not your suspension is compressed. To do this, you can measure from the center of the crank to the center of the rear axle. By releasing the air from the rear shock or removing the spring (depending on your setup), you can take the same measurement. You’ll want to size the chain to match the longer of the two positions.

Joining the Chain

As mentioned before, the type of chain you have could change how you join the chain, so there are multiple instructions here to accommodate the difference.

1. For Shimano chains, insert a joining pin in the two ends of the chain with the chain tool. When they pin has been set, you can snap off the end of it with the pliers you have at hand.

2. For SRAM and KMC chains:
     a. Insert the connector links of the two ends by hand.
     b. Snap the plates together so the chain is joined. You can use special pliers or pedal the connector link through            until it’s above the chainstay before grabbing the rear wheel to stop it from spinning while applying pressure             to the pedals. This will fully seat the link.
      c. At this point, for any chain type, you now need to run the bike through the range of gears you have to assure              proper fit and function.

Don’t forget about proper care of your bicycle chain once you’ve installed it. Your chain will last much longer and won’t cause harm to your bike if you regularly clean and lubricate it. when lubing the chain, don’t run it backwards and be in a hurry, as this can damage both the chain and the bicycle, and be sure to keep the grease way from the outside of the chain.


If you’re serious about taking care of your bicycle, you need to learn how to do proper maintenance, and one of the most important things to avoid more serious damage is to make sure your bike chain is in good working order. If you let it go too long without changing it, you can cause extensive problems that will cost a great deal more money to repair, and you’ll find you’re working harder than necessary to ride in the process. Keep in mind that your bicycle is like a car, and there are certain essential procedures, and if you are uncomfortable doing the work yourself, you should find a trusted bicycle mechanic to check in with from time to time so that you can make sure your bicycle is functioning properly on all fronts, especially when the drivetrain is involved. And if you need more of a visual on how to change and fit a bike chain, check out this helpful Youtube Video!