Tips to Choose the Number of Links in a Mountain Bike chain


Since the first bike chains were created sometime during the 17th century, they have gone through a lot of development through innovative thinking that came with progressive human advancement. Multiple chains with varying chain links have been created, each being used on different types of bikes. For proper fitting and maintenance, it is important to know the number of links in a mountain bike chain.

Most mountain bike chains have 116 links and can fit 8 to 24 chain speeds. However, some mountain bike chains come with 112, 114, 118, or 126 links.

Da Vinci is credited with being the first person to develop the conception of a chain and cog system as explained in this article from The Science of Cycling, back in the 1600s. Since then the mountain bike chain has evolved to be as we know it to be today. 

Mountain bikes most commonly need chains with 116 links because that’s the ideal chain length. However, because mountain bikes are made by different brand manufacturers, mountain bike chain lengths can vary. This is because chains have different chain speeds and generally, mountain bike chains can fit about 8 to 24 chain speeds, depending on the number of links they have.

It could be helpful to count the links if you need to know how to tighten a mountain bike chain as we explain in our step-by-step guide. Additionally, our tips and tricks to finding the difference between mountain bike and road bike chains might help you choose the right one for your next bike.

How to Count MTB Chain Links

Mountain bike chains are arguably one of the strongest types of bike chains. They are widely known for their toughness and tensile strength. Counting the MTB chain links might sound easy, but it’s more complicated than it seems. And it’s an important skill to have. If you don’t know how to count the chain links, it’ll be hard to replace the chain of your mountain bike when damaged. 

There are three easy ways to count the number of MTB chain links: counting the number of joining pins, counting the number of inner plates and adding the number of outer plates, or counting the number of spacings between chain pins.

Matthew Donald Kidd explains the mechanics of a bicycle chain in his thesis on bicycle chain efficiency. He notes the importance of the chain transmitting the force from the riders' legs on the pedal to the bicycle's wheel. There is a need to design mountain bike chains and chainrings with durable materials because of the terrain they’re built for. 

Several MTB chain manufacturers like SRAM and Shimano include the number of links in the chain you want to buy like this one and this one respectively. So if you intend to shorten the mountain bike chain for a specific reason, counting will help you determine where to cut the chain and properly determine the number of links in a mountain bike chain.

Method 1. Counting the Number of Joining Pins

Joining pins are the little pins attached across the entire bike chain. These joining pins are located at both ends of the outer plates, and they help to connect the outer plates to the inner ones. If you want to count the joining pins, you would have to look at the outer plates and count the pins you can see on both ends.

Counting all of these pins fastened tightly to the outer plates gives you the total number of joining pins on a mountain bike chain like this, ultimately, allowing you to estimate the number of chain links an MTB chain has. It is important to note that mountain bikes have varying joining pin numbers on their bike chains. However, this method is usually more helpful for motorcycles, which count the pins as the number of chain lengths, which is not the case with mountain bikes.

Count the number of joining pins to calculate the number of links in a mountain chain.
There are usually two connecting pins on the outer plate of an MTB chain, they help to hold the outer plate and inner plate together. Image Source: Amazon

Method 2. Counting the Number of Inner and Outer Plates

If you want to count how many links your MTB chain has by counting the chain plates, you must count the number of outer plates on your bike chain. The number of outer and inner plates is the same on every bike chain. You can either count the outer or inner plate, whichever you find easy to count.

As you may already know, outer chain plates are located on the outermost part of the chain. In fact, these outer plates are what give the bike chains their form. Bike chains also consist of inner plates. 

The outer plates are seen way more easily compared to the inner plates. Connected by rivets, these plates can be counted quite easily. Use a grease pen or easily removable tape (you don’t want the tape to leave any residue behind) to mark where you’ve started, then go all around the chain and count the inner or outer plates. Multiply that number by two and you have the chain length.

Count the number of outer plates that are the easiest to see, to calculate the number of links in a mountain bike chain.
A mountain bike chain is made up of inner and outer plates with rollers, all held together by pins. Image Source: Liberty Bell Bicycle.

Method 3. Counting the Number of Spacings Between Chain Pins

Finally, the last way to count the chain links on a bike chain is to count the gaps between each chain pin. These gaps are there in order to facilitate the bike’s movement. To do this, all you need to do is take a look at the chain and count the spaces between each chain pin. Just like with method two, use a grease pen or easily removable tape to mark where you’ve started so you don’t accidentally count any gaps twice.

Calculate the number of links in a mountain bike chain by counting the gaps between each connecting pin.
Count the visible gaps between each connecting chain pin to figure out how many links are in your mountain bike chain. Image Source: Amazon.

How Many Links in a 7, 8, 9, 10, 11, or 12 Speed Chain?

It is crucial to get the number of links in a mountain bike chain correct for a smooth mountain bike ride. If the chain is too long, it might drop off the chainrings when switching gears. This can cause a crash or damage to your chain, chainrings, or cogs. But if the chain is too short, the chain puts too much stress on the drivetrain (which includes the pedals, cranks, chainrings, chain, cogs,  and derailleur) and can damage those parts. So, it’s crucial to purchase the right chain length for your mountain bike’s number of gears.

A 7-speed chain has 114 -116 chain links, an 8-speed chain has 116 chain links, a 9-speed chain has 116 -118 chain links, a 10-speed chain typically has 116 chain links, an 11-speed chain has 116 -118  chain links, and a 12-speed chain has 126 chain links.

Typical Number of Links in a 7-Speed Chain

A 7-speed chain has 114 -116 chain links

Typical Number of Links in an 8-Speed Chain

An 8-speed chain has 116 chain links.

Typical Number of Links in a 9-Speed Chain

A 9-speed chain has 116 -118 chain links.

Typical Number of Links in a 10-Speed Chain

A 10-speed chain typically has 116 chain links.

Typical Number of Links in an 11-Speed Chain

 A 11-speed chain has 116 -118  chain links. 

Typical Number of Links in a 12-Speed Chain

A 12-speed chain has 126 chain links.

Chain Links Size Versus Chain Speed Chart – Examples of MTB Chains

Chain Speed Number of Links Example from Amazon Price
6 speed 116L Single/6/7/8/9/10 Speed Bike Chain Kit ~$20
7 speed 116L ZONKIE 6/7/8 Speed Bike Chain ~$20
8 speed 116L KMC Z8.3 Bike Chain ~$20
9 speed 116L KMC 9 Speed Chains ~$35
10 speed 116L  YBEKI Bike chain ~$20
11 speed 118L KMC X11 ~$35
12 speed 126L KMC X12 Ti-n Chain ~$95

How Long Should a Mountain Bike Chain Be?

Most mountain bike chains have 116 chain links. However, depending on the model, this number could vary slightly. Knowing the correct mountain bike chain length helps prevent issues like chain jamming or putting excessive stress on the drivetrain. Dozens of bikers and adventurers have complained about shorter bike chains affecting the quality of their rides. While you can always cut down a chain that’s too long, it’s not as easy to attach extra plates to make a chain longer (but it is possible). To avoid having to deal with cutting or adding links to a chain, try to buy the correct chain length for your mountain bike from the get-go.

The correct mountain bike chain length should be equal to the number of teeth in the largest chainring divided by four, plus the number of teeth in the largest sprocket divided by four, plus the length of the chainstay in inches multiply by two then add 1 inch.  

To calculate how long your mountain bike chain should be, use the following formula: (chainstayx2) + (chainring/4) + (rear sprocket/4)+ 1 = correct chain length (in inches)

That may seem pretty complicated, so here are the individual steps laid out for you:

  1. Count how many teeth the largest chainring has. Divide this number by 4.
  2. Count how many teeth the biggest rear sprocket has. Divide this number by 4.
  3. Measure the chainstay length and multiply that by 2.
  4. Add all these numbers and add one inch to get the correct chain length.

How to Measure Mountain Bike Chain Length

Measuring your bike chain’s correct length is imperative for your drivetrain to work optimally.

There are four methods to measure mountain bike chain length: measure the new mountain bike chain against the old chain, use the biggest chainring and biggest sprocket combination, measure chainstay length, and use the number of sprocket and chainring teeth.

To replace a worn-out or damaged mountain bike chain as explained in this article by Park Tool, you’ll need to buy another one that’s the same length. However, your new chain might not be exactly the right length for your bike, so you’ll need to measure it before installation. This avoids any damage that might happen to your bike if you ride with the wrong length of chain.

And who knows, maybe your old bike chain wasn’t correct either! This way, you can make sure that you’re riding with the chain length that will work best with your mountain bike. And if you need some help with mountain bike chain installation, be sure to check out our article.

Method 1.  Measure the New MTB Chain Against the Old Chain

Step 1. Measure the New MTB Chain Against the Old Chain

An easy way to measure a new mountain bike chain is to measure it against the old one. Lay the old chain right beside the new chain, both on their sides.  For those who have master links like this, be sure to include this master link in your measurements. If you don’t include the master link, that means your mountain bike chain will be a little short and not perform as well on your mountain bike. 

To hold the new and the old mountain bike chains side by side thread a long rivet through the links at the ends of the chains.
Use a long rivet to hold the old MTB chain and the new one side by side. Image Source: wikiHow.

Step 2. Shorten the New Chain to Match the Old Chain. 

If there are any extra links in a mountain bike chain, you’ll need to remove those before installing the chain onto your mountain bike. While preparing to cut, place a long rivet through the end of both chains to keep them together and align each chain link side by side to make sure the measurement is accurate.

Additionally, make sure to take the old chain’s stretches into account. The old chain will most likely have stretched in certain areas due to normal wear and tear. This is why you need to place the two chains side by side, making sure the rivet on the old chain matches the one on the new chain at the end where you will be cutting.

If all is set, remove the extra chain length using a chain breaker tool from a kit like this, which allows you to remove the connecting pin of the chain at the point where you want the chain to end.

Method 2. Use the Biggest Chainring and Biggest Sprocket

Step 1. Wrap the Chain Around the Chainring and Sprocket.

The chainring and sprocket are located at the front and back wheels of a bike, respectively. Another way you can measure your mountain bike’s chain length is to fit the chain on the biggest chainring and sprocket. Mark the link on the chain with a grease pen where the chain from the sprocket end and chainring overlaps. To be on the safe side, leave 3 extra links before you cut.

When measuring your mountain bike chain, leave three extra links just in case.
Leave three extra links when first cutting the new mountain bike chain. Image Source: Enduro Mountain Bike Magazine.  

Step 2. Shorten the Length of the Chain With a Chain Riveter.

When you fit your mountain bike chain using the chain and sprocket method, you’ll probably have a chain that dangles a bit. Cut off the extra length, using a chain riveter like one from a set like this, a little bit at a time until you can easily change gears up and down the whole sprocket over both chainrings. Test this each time until your chain length is correct. This will take some time, but be patient. You don’t want to cut the bike chain too short and have to add links back to it, which is much more difficult than removing them. 

Use a multitool chain breaker to remove the extra links of your mountain bike chain.
Use a chain riveter to undo the excess chain links and get the correct measurement. Image Source: RedBull.

Method 3. Measure Chainstay Length and Use Sprocket and Chainring Teeth

Step 1. Measure Chainstay Length

The first thing you need to do is to measure your bike’s chainstay length, which is the distance from the bottom bracket to the center of the rear wheel’s sprocket. 

By measuring this, you’ll be able to determine the required chain length for your bike. To measure the chainstay length, you must measure from the bike's side view.

To make sure that your chain length is correct with the correct number of links measure the length of the chainstay on your mountain bike.
Measure the chainstay length from the bottom bracket to the center of the rear wheel’s sprocket. Image Source: DIY Mountain Bike.

Step 2. Determine the Number of Teeth the Big Chainring Has.

After measuring the chainstay length, determine how many chainring teeth your bike has. Most mountain bikes have the number written on the big chainring. It is represented with the letter T. If your chainring says 52/36T, that simply means your big chainring has 52 teeth. If this number is not there, then you’ll need to count them by hand.

Check to see how many teeth your chainring has by looking at the figure on the side of the chainring itself, or by physically counting the teeth.
Most mountain bikes have the number of teeth written on the chain ring. Image Source: Road.cc

Step 3. Determine the Number of Teeth the Biggest and Smallest Sprocket Has.

Just like reading the number of teeth of the chainring directly from the chainring of a bicycle, the number of teeth of the biggest and smallest sprocket can easily be read on the sprocket like this. If it says 11/28T like this one does, that means that the number of teeth on the biggest sprocket is 28 and the smallest sprocket is 11. You can also refer to the user manual of your MTB bike to see if it’s listed there, or you can count the number of teeth yourself. Check out SRAM’s various manuals to see what their specifications are.

Step 4: Calculate the Length of the Chain Using a Formula

Once you have recorded your observation, it is time to calculate the chain length using the formula previously stated. You can calculate the chain length using the formula, which is: 

Chain length = (chainstay x 2) + (chainring / 4) + (rear sprocket / 4) + 1-inch

Chainstay is the length you measured in step 1, which is the distance between the middle of the chainring and the center of the sprocket. The chainring is the number of teeth on the biggest chainring, and the rear sprocket is the number of teeth on the biggest rear sprocket.

How to Size a Mountain Bike Chain

Sometimes, it’s super obvious when it’s time to replace your mountain bike’s chain. For example when it is clearly broken from impact during a fall or collision. But there are other, less obvious signs that it’s time to change out your chain - if your gears keep slipping or it’s flexing more than it used to, then it’s time to replace the chain. And you need to size your new mountain bike chain correctly for a smooth ride.

To size a mountain bike chain, start by releasing the tension of the chain, cut and remove the old chain from the mountain bike, size the replacement mountain bike chain using one of the methods listed above, and finally, install the new mountain bike chain.

But for certain issues, like if  your mountain bike chain keeps hitting the frame or your mountain bike chain keeps jumping gears or skipping, check out our articles to see if you can solve the issues before going out and buying a new chain. Another possible solution for mountain bike chain problems could be to install a mountain bike chain guide, be sure to check out this article as well.

Here are the steps to size your mountain bike chain:

Step 1. Release the Tension in the Chain.

Release the tension in the chain of the bike so you can work with the chain. First, locate the derailleur screw somewhere at the back of the derailleur. Most MTB manufacturers mark this as the B- screw for easy identification.  Loosen the screw in an anti-clockwise direction until the tension in the chain is released.

Loosen the tension of the mountain bike chain links by locating the B-screw on the derailleur and loosening it in an anti-clockwise direction.
The derailleur screw is usually marked with a B.  Image Source: Park Tool

Step 2. Cut and Remove the Old Chain.

To remove your old bike chain, use a chain breaker tool that will remove a linking pin that holds the inner and outer plate together. Carefully remove the chain and set it beside the new one that will be replacing it. You should put an old towel or tarp underneath the chains to protect your working surface from chain grease.

Undo the old chain by breaking it apart with a chain breaker tool.
A chain breaker removes the linking pin holding the bike chain together. Image Source: Keely Thomson.

Step 3. Size the New Chain

After removing the old chain, the next thing you need to do is to size the new chain. Many chains like these are designed to have more links than the user requires. Chain manufacturers do this because of the varying size of mountain bikes. When buying a new chain, make sure you are buying the appropriate chain for your mountain bike.

To size your chain properly, you can use any of the methods explained earlier. For this section, we’ll be using the biggest chainring and sprocket method.

Wrap the new chain on the chainring and sprocket of the bicycle and leave the remaining chain dangling. 

When sizing your new mountain bike chain overlap the ends and cut it leaving extra links like this.
To size the new mountain bike chain, this person will cut at the red mark. Image Source: The Bike Tube.

To get the correct length of chain you need to first, put your chain through your front derailleur, then onto the largest cog through the cassette. Do not pass the chain through the rear derailleur. The actual chain length is the distance around the largest sprocket and chainring with an extra two links and a master link. This extra link helps to compensate for the derailleur that was bypassed.

When you are ready to connect your new mountain bike chain make sure that you leave enough length for suitable slack when changing gears.
When sizing using the biggest chainring and biggest sprocket, the link marked in red will be cut. Image Source: Park Tool.

Step 4. Install the Chain

After removing the extra chain length, you need to join the 2 ends of the chain together. Before connecting your new chain, make sure that the chain is threaded through the rear derailleur. Then you can install the chain.  Most bikes allow the use of master links, but sometimes you have to use a chain pin as shown in this article by REI.

If your mountain bike can use master links, you put half of the master link onto each mountain bike chain end. Then pull the ends together and use a master link tool like this so the link clips into place.

But if there’s no master link, then you’ll need to use a chain tool like this to reconnect the chain. There should be an extra chain pin included with your new chain. And if you’re simply repairing a chain, go ahead and use a new connector pin like this that’s compatible so your chain lasts longer. 

And when you’re using a new chain pin, you usually insert them halfway in first using the chain tool. Then, use pliers to break off the end that’s sticking out. Then, your mountain bike has a new chain that’s ready for a ride, but be sure to check out our guide on how to clean a mountain bike chain properly and lube it before you go.

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