How to Put a Chain Back on a Mountain Bike

Last Updated on September 12, 2022

Mountain biking is no easy sport. You climb steep off-roads for hours at the end and descent through narrow and seemingly unpassable trails littered with slippery roots and jagged rocks. Many would think a mountain bike can’t deal with all the stress you and Mother Nature throw to it. But it can!

But there will come a time when the chain would suddenly slip off from the drivetrain. You can usually just put it back. And sometimes, you need to replace it with a new one.

Knowing how to put a chain on a mountain bike is an easy task, but you need to do it right to avoid damaging the parts.

That’s just what this article is about.

Here, we’re going to give you a step-by-step guide on how to put a chain back on a mountain bike — the right way.

Returning a Slipped Chain

This is a simple problem that can be easily fixed. You need to do this carefully, though, because this can chip off some paint or ruin a component if done wrong.

Step 1: Locate the slipped chain

Search where your chain has slipped off so you will know how you need to take care of it. It usually comes off on the back sprocket or the crank’s chainring.

Step 2: Untangle the slipped chain

Sometimes the chain gets tangled around the rear wheel or on the frame of your mountain bike. Loosen the rear wheel or the area of your bike where the bike chain has latched on.

Forcibly untangling the chain can either damage it. It can even scratch-off paint from your frame, which you surely don’t want to happen, right?

Step 3: Return the slipped chain to its original place

Loosen the bike chain and then push the rear derailleur pulley. This lets you bring back the chain to its proper position. Cycle it around by turning the pedals and pressing the shifter simultaneously.

This lets you see if it shifts properly or if it needs adjustment. But don’t bring it to the point chain pin can lead to a loose chain because this will be dangerous for your new ride, even if you have a new chain.

Note that having a new chain means that you first need to break them in to get the most out of them. You can also use a chain link for bike chains to adjust it to your preferences.

When to Replace Your Old Mountain Bike Chain

Putting back the bike chain on your mountain bike is the first thing you’ll do. But it’s also a good idea to check it first and see if it’s already worn out. If so, then it’d be best that you replace it with a new chain. Remember that bike chains last for a few years only.

Riding with a worn-out chain can damage your drivetrain if it’s overly stretched out. You can even get injured if the bike chain snaps while you’re pedaling.

Make sure that you let a professional bike mechanic check your new chain or Shimano chain every once in a while so they can see if the master link is still in place and the big ring position along with the gear lever is still intact.

The rear derailleur forward length should be also maintained regularly by a bike mechanic so that there won’t always be a new chain length which you should always adjust by a chain breaker for multi speed bikes.

Related: What to Look for When Buying a Used Mountain Bike

Installing a New Chain

Tools you’ll need

Putting the bike chain back is a simple task just like putting a back tire on your bike. But you need tools to get the job done right.

Here are the tools you need when installing a new chain:

  • Chain – Make sure that the chain is compatible with your drivetrain so that it’ll run properly. Get the same brand and gear range compatibility of the old chain so it’ll run smoothly.
  • Replacement pin/master link – This is the connector that brings both ends of the chain together. This must also be compatible with your bike chain so it could fit on it.
  • Chain tool – Cutting your new bike chain is important because it must be at the perfect length. This prevents it from easily slipping off. It also ensures that your drivetrain shifts properly when you move the chain back.
  • Master link pliers – a dedicated chain tool that simplifies connecting your master link and makes it easier for you to adjust the chain back, especially if you have a new chain.

Steps on installing a new chain

Step 1: Taking off the old chain

Disconnect the master link to take off the old chain. You can use the chain tool to remove one link on the bike chain if there isn’t a master link. Shift your gear to the smallest chain ring to make this process easier for you.

Step 2: Fit in the new chain

There are several methods to get the correct chain length. The easiest one of them is to match the number of links of your new bike chain to the previous one. Then cut off the excess chain using a chain tool. This is common if you have a master link.

Another method is to attach it to your biggest cog without threading it to your rear derailleur. See where each link meets and add two more links to get the correct bike chain length.

Step 3: Install the chain to your bike

Put the rear derailleur on the highest gear and attach your new bike chain on the smallest cog. Thread it through the rear derailleur before linking it together. This step will also be easier if you have a bike stand for full suspension mountain bikes.

Simply lodge the front wheel or rear wheel straight into the bike stand and it will stand on its own.

But you also need to make sure that you put the chain back properly and the ends of the chain won’t rub against the frame and outer plate. Nonetheless, you can just do a simple flip bike and put it upside down if you don’t have a stand.

Step 4: Link the chain

Install the bike chain pin by using a chain tool. This inserts it through the links of your new bike chain. Then remove the front excess of the pin using pliers.

After that, check if the rear derailleur is properly set up with the bicycle chain, rear wheel, master link, rear axle, and front derailleur if you have one.

Then adjust it using chain wear tools or a master link tool to align the chain properly, especially if you have Shimano chains or KMC chains as these are the top brands in the market.

linking the chain

The other method is by reconnecting the chain with a master link. This is much easier compared to the first method. Attach each half of the master link to both ends of the chain and then snap them together using a master link chain tool.

The ends of the chain should also be smoothly combined with the master link. Note that the master link plays a huge role in your bike’s performance, knowing that it is a main component of your bike chain.


Knowing how to put a chain on a mountain bike is an important thing to learn.

Many will say that you can’t be a real mountain biker if you don’t know how to do it! It might sound silly, but it’s true because you don’t just ride your bike. You also need to know how to fix it and put a chain back if worse comes to worst.

And one of the most common issues you get is a slipped off chain.

conclusion - putting chain on the mountain bike

Hopefully, this article helped you out so you don’t have to annoy your friends into putting back your chain the next time you ride your bike.