Bicycle Chain – ULTIMATE GUIDE

The bike chain is one of the most crucial components of your bicycle. A faulty chain can lead to a host of issues, including limited shifting. However, the primary reason for managing your bike chain is to prevent damage. Nobody wants to contend with a chain that slips off the cogs while riding.

Having a fundamental understanding of your bike chain is essential in this scenario. With proper maintenance, you can ensure that your bike performs at its best. The ultimate goal is for your bike to function as if it were brand new. To achieve this, you must comprehend how the chain and the entire bike’s drivetrain operate.

To help you optimize your performance and achieve the best results from your bike, we have crafted this article. Our article will explore various factors related to your bike chain, and we will guide you through the process of fixing and managing your bike chain. We will also highlight the risks that those who neglect their bike chain face.

Bicycle Chain - ULTIMATE GUIDE

How Bike Chains Work

To fully comprehend the other information provided, it is crucial to understand how a bike chain functions. Bike chains are a crucial part of the bike as they allow the rider to shift between different speeds. This shift in speed increases tension on the pedals, propelling the bike forward. Chains are responsible for connecting the rear wheel to the front of the bike.

Although this process may seem simple, it’s important to note that there are two different types of bike chains that you should be aware of. Depending on the type of bike used, one of these chains will be present on the bike.

Here is a basic breakdown of the two chains you will encounter on your bicycle:

Single Speed Bike Chain

You may have observed that many bikes have only one speed. The chains that drive these bikes are somewhat distinct from drivetrain chains. These chains work optimally when there is one sprocket on the crankset and one sprocket on the wheel. The rollers on these chains are usually 1/8 of an inch in thickness.

Single Speed Bike Chain
Single Speed Bike Chain

The chain on these bikes is not designed to move from one sprocket to another. Instead, it works by regulating the geared speeds internally. Even though it may seem like it has multiple gears, it is still classified as a one-speed chain. As the rider, you won’t be able to adjust any changes in pedaling difficulty or tension.

Multi Speed Chain

Most road bikes and mountain bikes feature derailleur chains, which are engineered to switch between different sprockets. However, selecting and maintaining them can be slightly more challenging due to their design. Nevertheless, these chains offer greater control over movement.

multi speed chain
Multi Speed Chain

It is often a tough process to find the right chain when you are looking for a new one. However, you will need to focus on the rear hub of the drivetrain to make the best decision. Rear cogs can vary in numbers and they are generally 5, 6, 7, 8, 9, 10, 11, or 12 sprockets, which means that the size between the rivets on your chain will vary depending on the sprockets. Here is a small breakdown:

  • 12 rear cogs – 5.3mm
  • 11 rear cogs – 5.5mm
  • 10 rear cogs – 6mm
  • 9 rear cogs – 6.5 to 7mm
  • 8 rear cogs – 7mm
  • 7 rear cogs – 7mm
  • 6 rear cogs – 7mm

It’s worth noting that the size of the chain also impacts the front of the bike. The chainrings should be wide enough to fit the front of the bike, depending on the different speeds it offers. It’s your responsibility to determine which size will be optimal. However, when selecting a bike chain, it’s advisable to ensure that the front and rear of the bike work in harmony.

Chains for electric bicycles

With the surge in electric bicycles, manufacturers started providing specialized components, with the chain being arguably the most crucial one. In the case of electric bicycles, the chain is subjected to stress not only from the rider’s power but also multiple times from the engine’s power.

Electric bicycle chains are characterized by a longer service life, which is achieved by strengthening the material with a link and using harder, more durable pins.

Choosing The Right Chain

One of the most intimidating challenges is selecting the appropriate chain. However, you can refer to the drivetrain manufacturer for guidance. For most bike models available, you will often come across two popular names – SRAM and Shimano. If you’re uncertain, it may be best to choose the same chain recommended by the manufacturer.

Bike Chain Diagram

Bicycle chains are made up of several pairs of steel outer (1) and inner links (2) connected by pins (3). Each of these pairs divides between the rings (5). The pin (rivet) is tightly stretched through both outer links and freely rotates in the inner and intermediate rings (4).

Bike Chain Diagram
Bike Chain Diagram

Every modern bicycle chain is manufactured according to the “one-half inch pitch” standard, meaning the distance between the pins is 0.5 inches (about 1.27 cm).

The sprocket teeth are manufactured to the same standard so that any standard bicycle chain can be used. However, this does not mean that all chain models are interchangeable.

Are Bicycle Chains Universal?

No, not all bicycle chains are the same, and therefore not all chain models are interchangeable. Each type of chain has specific characteristics that make it compatible with certain types of bicycles. For example, a BMX bike will require a different chain than a mountain bike.

When buying a chain, some packages also include a Chain Link Connector:

Joining chains is a critical aspect, and nowadays, chain connectors are primarily used for this purpose. These connectors don’t require any tools, unlike regular chain riveting, which demands a chain riveter and appropriate skills.

Chain links, like chains, come in different widths, which are determined by the number of gears they are intended for. Clutches for chains with 6, 7, and 8 gears come in the same size, whereas those for 9, 10, 11, and 12 gears are unique to each chain.

Additionally, they vary in shape, with each manufacturer having their specific links. In the picture, I have included some couplings from different manufacturers.

Type of Master Links
Type of Master Links

Chain dimensions or Size

The size of the chain is an important factor for the entire transmission system to function properly. Most often, the biggest question is how to choose the right chain size when replacing it. In general the best bt is to use the same size as was on the bike when you bought it.


As I mentioned above, the width of the chain is also determined by the number of rear wheels. The more wheels there are, the smaller their spacing is, which also changes the width of the chain. Using the wrong width can cause the chain to fall off the sprocket or get stuck.

The table below shows a summary and indicative dimensions of the outer and inner width of the chain.

Drivetrain CapabilityWidth (Inches)Width (MM)Internal Width (Inches)
5/6/7/8 Speeds9/32-inches7.1-7.3 mm3/32-inches
9 Speed¼ – 9/32-inches6.5-7.0 mm11/128-inches
10 Speed¼ – 9/32-inches6.0-7.0 mm11/128-inches
10 Speed Narrow7/32-inches5.88 mm11/128-inches
11-Speed7/32-inches5.5-5.62 mm11/128-inches
12-Speed13/64-inches5.3 mm11/128-inches


Each chain has its length determined by the number of links. Of course, the more there are, the longer the chain. This number is always indicated on the chain packaging and is given in numbers, for example, 114, 116…

With use, the chain is lengthened, or the individual links are stretched. Its extension should be monitored regularly so that it does not cause damage to other parts of the transmission and does not cause a fall or injury to the rider. I write about it in more detail in the chain life section.

What Material Are Bike Chains Made Of?

The primary material used in manufacturing chains is steel or stainless steel. Around 90% of bicycle chains receive an additional surface treatment. Some manufacturers use materials like titanium to make chains that are as lightweight as possible while maintaining optimal properties.

Surface treatment

Surface treatment is a crucial factor to consider. Inexpensive chains typically have no or minimal surface treatment, which doesn’t protect them from corrosion. Conversely, higher-quality chains typically have superior surface treatments.

Different parts of the chain may have different surface treatments. For instance, the inner and outer plates may not require the same coating since each has a unique role. The outer chainrings are only used when shifting from an internal to an external cog, whereas the internal chainrings engage with the cassette cogs as the chain moves up.

Here are examples of surface treatments:

  • GST (Greener Surface Treatment) – ecological surface treatment that lasts up to a thousand hours of use
  • DHT (Diamond Hard Tech) – extremely hard surface treatment guarantees great wear resistance
  • EPT (EcoProTeQ) – surface treatment that doubled the service life. A smoother surface reduces noise and maximizes rust resistance. The technology belongs to KMC.

How Long Does A Bike Chain Last?

The lifespan of the chain depends on several factors, including usage rate, distance covered, and terrain type. A road bike ridden by a recreational cyclist needs to be replaced after covering 3-4 thousand kilometers, while MTBs last around 1,000 kilometers due to harsh terrain conditions and mud.

The difference between 11-speed and 10-speed chains is not very noticeable, but 9-speed chains were previously known to be more durable. However, the lifespan of the chain also varies based on the manufacturer and the material and surface finish used. There are several options available on the market, and some manufacturers guarantee up to 10,000 km of use on a single chain, such as KMC.

It’s difficult to determine exactly how long a chain will last as it depends on the rider’s style, outdoor conditions, and how diligent they are about regular maintenance.

What’s Included in Chain Maintenance

As I mentioned above, extending the life of the chain and the entire drive unit is possible thanks to proper maintenance.

The process is pretty easy:

  1. Clean the chain with something like this cleaner.
  2. Lubricate the chain with chain lubricant.

A cleaned and well-lubricated chain is the precursor of longer service life. You need to use the right lubricant.

But how far can maintenance take you, and how do I know if it’s the right time to change my bike chain? The next part of this article will help you in your decision.

When is it time to replace the bicycle chain?

Since the life of the chain depends on various factors, wear must be checked during regular bicycle maintenance. This check also depends on the driving style, but it is advisable to set it every 800 km.

A pulled and worn chain destroys the converters and pinions; in that case, we would have to replace the chain and these components. Ultimately, we would have to reach deeper into our pockets.

There are 2 basic ways to find out if the chain is stretched:

  • Visually
  • Using a caliper

When measuring with a scale or caliper, you must follow these principles:

When measuring the chain, it’s crucial to measure it in three to four different places. The section being measured should not have any coupling. Additionally, the measurement should be taken under a light load.

If you discover that the chain has exceeded its useful life, don’t hesitate to replace it.

Dangers Of Neglecting The Bike Chain

The bike chain is a critical component of the bicycle, and it’s vital to maintain it in top condition. Bike chain rust is a common issue that cyclists may encounter, especially if the bike is left outside. Here are some of the risks to keep in mind if you neglect your bike chain:

Missing Shifts

Bike chain rust can cause one of the most significant issues – the cogs can become obstructed from entering the chain links. This can lead to the chain jumping off the cogs, leaving the rider with an unmanageable bike. The worst-case scenario is that the chain could snap due to the high amount of friction created. It’s essential to note that rust can weaken the chain’s structural integrity and cause damage.

Snapping The Chain

Another significant risk associated with a neglected chain is that it could snap, which is incredibly dangerous and can result in severe injuries. While the bike’s brakes may still work, it may be too late to slow down the bike in time, particularly if the chain snaps while traveling at high speed. This puts the rider at risk of falling and being injured.

By managing your bike chain regularly, you can avoid potential damage to the chain and stay in control of its wear and tear. This way, you will always know the exact condition of the chain, and you won’t risk a sudden chain snap while riding.

Additional Damage To The Bike

Using a rusty chain can also lead to the wearing out of the cogs on the sprockets. The constant friction caused by the rusty chain can cause damage to the drivetrain, and replacing it can be expensive. It’s best to avoid this scenario if possible to prevent incurring costly repairs.

Serious Injury

When you’re confident in your bike’s performance, you may take more risks, which can be risky when unexpected events occur. A snapped chain is an unforeseen event that can catch you off guard. If you’re traveling at high speeds or riding through steep mountain passes, a chain snap can cause you to fall, leading to severe injuries.

Final advice about bike chains

Manufacturers often produce bicycle chains, converters, cassettes, or derailleurs as a single unit to ensure everything works optimally. If you’re unsure which bike chain to select, it’s best to stick with the manufacturer’s brand of the transmission assembly you have.

About Martin

I am Martin, I am the author of this blog. My main interests include cycling. That's why this blog was created. I have always been interested in technology and how bicycles are made, so I built one myself.

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