An Easy Guide to Determine How to Measure a Bike Chain

Are you a new bike owner who’s finding the technicalities of their shiny new ride a little intimidating? The most essential thing you should begin with is your bike chain, more specifically, the chain sizing. Now you must be wondering exactly how to measure a bike chain length.

You could go to a bike fitter for this. On the other hand you might want to try doing it yourself. If that is the case, this article will walk you through the details.

How To Determine Bike Chain Length 

Your chain is an integral part of your bike. It’s the central functional unit of your bicycle, followed by the wheels, of course. So ultimately, it is prone to some significant wear and tear. Bikes are composed of rivets as well as rollers. These components cause the chain to increase in length.

With the passage of time, as the rollers and rivets get used, they will stretch the chain and cause the length to increase. This can be a prominent marker of the age of a bicycle chain. 

So if you’re trying to determine if your chain is worn out or not, you should know how to measure a bike chain length. A shiny new bicycle chain is 12 inches long over 12 of its links.

If a chain does not comply with the above specification and measures somewhere around 12 1/16 inches over an exact number of 12 links, then it’s time to buy a new one.

There are a few ways to get the correct chain length on your road bike, as Dan Lloyd will show you in this Global Cycling Network Youtube video.

Tools Needed 

Now that we have established the need for a new bicycle chain, the next step is to decide its specifications. These specifications aren’t too complicated. All you need to focus on is bike chain measurement.

The tools you need to measure the bike’s chain depend on the type of chain you have. These are of two types:

1. Master Link Chain: This type of chain is connected by utilizing outer chain links for connection. These external chain links are removable.
2. Connection Rivet Chain: As the name suggests for the connecting rivet chain, the connections are made by using rivets

The choice of tools is dependent on the above types of chains. These include:

• Chain Tool: To cut the chain for the purpose of size reduction
• Master Link Pliers: Specifically designed to separate the chains containing master links

Check & Remove Chain

A vital factor to note before you go ahead and dismantle the old chain from the bike is to make sure that it is of the appropriate size. If you’re new at changing bike chains and are wondering how to measure a bike chain, then this is where you should start.

First of all, you must shift your bicycle into maximum capacity chainring as well as a back cog. The primary test your chain has to pass is to be able to convey this particular shift with double minor bends at every back derailleur pulley.

In the second step, you’ll have to shift over to the shortest chainring plus sprocket. During this move, there should be no lag or slack in the chain.

In addition to this, the derailleur of your chain should be such that it doesn’t pull back to such an extreme where the chain comes into contact with itself.

After this, it’s time for the removal of the back wheel. The purpose of this particular move is to relieve your chain of the tension that is being applied to it to provide you with better access to it.

Once you have removed this, try to locate the master links on the chain. This is done to identify the type of chain you have. 

Master Link Chains

If you have appropriately identified and affirmed that the chain is a master link one, then it’s time to use the relevant tools to cut it. You could use a Park MLP-1.2 plier to reduce its length. This plier is specifically designed to deal with master link type chains.

In another case where you might not have the Park MLP-1.2, and your chain has been subjected to sufficient wear and tear, you can just substitute this plier with a regular cutting tool.

This will successfully separate your chain at the point where you need it.

Connection Rivet Chains

Connecting rivets is relatively easy to identify since they are visually unique in contrast to other members of the riveting family. One thing you need to be vigilant about is that if you are trying to separate a certain rivet, it should be spaced at a small distance from another preinstalled connecting rivet. Now insert the chain tool by bringing the driving tool of the chain tool into contact with the connecting rivet.

At this point, the pin of the chain tool in question should be driving in an erect manner in the chain rivet for appropriate action.

Apply force as you turn the handle to drive the rivet outward. Now all you need to do is remove the chain.

Methods to determine chain length 

Now let’s see how to measure a bike chain length. Its technicalities and different methods will be included in this part.

Method #1: Size to old chain (count links) 

For sizing your new chain to an old chain, you need to make sure that the old one is of the appropriate size. Once you have verified the size of the old chain and deemed it appropriate, you can continue with the sizing of the new to the old.

Align both your chains on a flat surface. When aligning the two chains in a parallel manner, make sure that the outer plates of the old chain are in line with the outer chain of your new one. Similarly, the inner plate of the old chain should be perfectly aligned with the inner plate of the new one.

These steps are significant to get the exact measurement of your new chain. A good tip would be to utilize a master link here. Insert the master link For an exact and perfectly aligned side by side comparison of the two chains.

Also, make sure to align the chains with respect to rivets because as time passes, the chain is destined to increase in length. This owes to the wear and tear it will be subjected to while being used.

Method #2: Largest cog and largest chainring method

If you’re changing your bike’s chains for the first time, there is a good chance that you discarded the worn-out one without realizing its usefulness. In this case, here is another method if you’re wondering how to measure a bike chain if you simply don’t have an old chain as a reference to compare the size of a new one with.

To begin with, you will have to shift your front derailleur above the biggest chainring you can identify. Additionally, you will have to shift the back derailleur to the smallest cog.

You will first have to wrap the chain around the largest cog, and this is done by passing the end of the chain from the frontal portion of the derailleur cage on the biggest chainring.

Here you will hold it in the five o’clock position.

In the case of a master, link install only half of this link. This will provide you with almost half an inch of extra length after this following the same process as mentioned. 

Just pull the lower portion of the chain to fit. Next, you should attach it to the front chainring. 

Look for the nearest rivet where the two chain ends could be connected and use it as a reference, as this will be the point where you make the cut.

Method #3: Chain sizing by equation

The bicycle chains are technical as well as mathematical entities. They are composed of inner plates as well as outer ones. The chains are linked to each other when an inner plate comes in contact with an outer one. 

This allows the chains to be connected at whole-inch increments. This means that a chain can be 53 inches (just an example), but it can not be 53-1/4″, or it can be 56 inches, but not 56- 1/2″.

This makes it convenient to measure the chain by industrial drive train equations.

You’ll first count the front teeth on the biggest front sprocket as well as the biggest back one.

Secondly, you will measure the space from the center of the crank bolt all the way to the back axle. Now measure the nearest 1/8″, and change this to decimal form.

Simple Equation

Now use this equation for calculations: 

Simple Equation: L = 2 (C) + (F/4 + R/4 + 1)

• L = Chain length in inches 
•  C = Chain stay length in inches 
•  F= Number of teeth on biggest front chainring
• R= Number of teeth on biggest back cog.

The simple equation is the more frequently used one. This is the equation for the uncomplicated and straightforward chains.

Rigorous Equation

The chain lengths that have a relatively complex infrastructure of chain cannot adapt the simple equation to provide the appropriate chain length. The reason behind this is the versatility of chainring sizes as well as the short dimension of the chainstays.

Hence the rigorous equation is used for these chains.

 Chain Length = 1+0.25*(F+R)+2√(C*C)+(0.0796*(F-R))²

• C – the chainstay length 
• F – the number of teeth on the biggest front chainring
• R – the number of teeth on the biggest back cog.

How to Keep Your Chain Top-Notch

Now that you know the proper bike chain length, it’s time to see how to keep it in mint condition. 

Thus, you must follow these steps to acquire a smooth and functional bike chain.

Items Needed

• An appropriate degreaser
• Cotton clothes and any old toothbrush
• A good quality chain lube
• A brush to clean the even the smallest cog, derailleurs, sprockets
• Chain cleaning tool
• Gloves

Clean the Chain

First, choose a location where you are free to create clutter. For example, you could head outdoors or to your community bike shop. Next, put your bike on a repair stand if you have one. 

However, if not, lift the front wheel properly so that the bike stands alone. On the other hand, you could flip the bike upside down and rest firmly on its levers and saddle. 

Furthermore, make sure your seat is on the cloth to prevent scuffing.

When cleaning a cycle chain, it’s essential to pay attention to the cogs and derailleurs. If left dirty, they’ll make your chain gunky in no time. For this, you can employ a gear-cleaner brush. This tool has two sides, each serving a different cleaning function. 

One side contains toothbrush-like bristles for scouring, while the other is curved and toothy for picking dirt between the gears.

Next, you should clean the chain. Moreover, you can use a piece of chain-cleaning equipment to aid you. This is a small container with wipers and rollers within it. So, you pour your solvent into the container, then clip it to the lowest piece of your chain. 

Next, clamp it in place and then backpedal many times. Then, empty the tool and rerun the operation with water and soap instead of solvent. Finally, just towel the chain dry.

However, if you don’t have access to these tools, you can use the conventional chain cleaning method. Simply take your rag and apply the cleaning solution to it. Next, place the chain between your cloth and hold it properly. In the end, just backpedal it till its whole length runs through the cloth.

Oil the Chain

Take a decent chain lube appropriate for your riding climate and apply it evenly to the chain. The most straightforward technique is to drip the oil consistently onto a specific place while backpedaling. This allows the entire chain to become saturated. Moreover, use a drip-type oil and oil around the inner circle of the chain – the section where the gears penetrate.

Wiping

After applying lubrication and allowing it to sit for a minute,  you will need a dry, clean bit of cloth. Next, grasp the belt and backpedal to mop up all the extra oil.

FAQ’s on How to Measure a Bike Chain

What should be the chain cleaning frequency?

You should clean and lubricate your chain anytime it begins to creak or seems gunky. Moreover, clean it well with a solvent before re-oiling it. Again, don’t leave extra lubricant on the band, as it will gather up dirt and grit, aggravating chain wear.

Which is an environment-friendly chain lubricant?

Humid conditions often necessitate bulkier oils and more frequent bike maintenance. On the other hand, drier conditions necessitate lighter oils that pick up less dust and sludge. 

Also, biodegradable soy-based greases have received positive feedback. However, you should only use lube which is particularly for bicycle chains. 

Conclusion on How to Measure a Bike Chain

This concludes all bike chain-related matters. Thus, whether it’s a speed chain or derailleur chain, you can handle it on your own. Moreover, we would advise that you start off by riding single-speed bikes. 

These are less complicated and easier to maintain. Later, once you get enough practice you can shift to riding the multi-gear versions.