Home » Road Bike Chains 101: A Guide to Types and Sizes

Road Bike Chains 101: A Guide to Types and Sizes

56 views

Most individuals remember the time they first learned to ride a bike for two main reasons: the pain of repeatedly falling, and the thrill of finally getting the hang of it. However, not many people stop to think about why the chain was always making that clicking sound, or understand the symphony of pins, rollers, plates, and links propelling the bike forward. Believe it or not, the bike chain is one of the most important features of a bike, and having the right fit is imperative to having a smooth ride, every time.

Is there a difference between bike chain types and sizes? Pedal power is converted into forward movement through the chain, thus making it essential that you purchase the right one and keep it well maintained. Bike chains differ depending on the following factors:

  • Coating and material
  • Manufacturing tolerances
  • Length

You may be content to stick with the chain your bike came with and never give it a second thought. If your chain wears and needs replacement, then finding a replacement that matches the name on the derailleurs is suitable. But, there are extra considerations that you can take if you seek better shifting, improved corrosion resistance, lighter weight, or even just saving a few extra bucks. Knowing the ins and outs of your bike chain and proper maintenance practices can go a long way in your bike chain’s longevity.

Are All Road Bike Chains the Same?

The chain is the key element to a bike’s transmission. It connects the front part of your bike, or “drivetrain,” to the rear.

You might hear modern bike chains being referred to as “roller chains.” Of all the individual parts that make up a road bike, the roller chain is the component that works the hardest. When your legs work the pedals, the roller chain is orchestrating communication between the cranks and chainrings/sprocket in the front, and the cassette/sprocket and rear hub in the back. They are made up of short  “cylindrical rollers” that are held together by “side links.”

You will notice small gaps between the rollers. These gaps mesh with the teeth on a sprocket or chainring, thus driving transmission when turned. For strength, a lot of road bike chains are made of alloy steel, but some performance models feature high-end alloy parts or hollow pins/side plates to save on weight.

While that is the basic functionality of all road bike chains, there are still several factors to consider when looking for a replacement. The type of chain you need will heavily rely upon the kind of bike you are riding and how you plan on riding it. Factors like coatings, materials, manufacturing tolerances, and metal treatments can directly impact the efficiency and durability of a road bike chain.

Coating and Material

A significant factor in determining the price of a road bike chain resides in the coating and materials used to make the chain. Keep in mind: this is a factor that mainly impacts the price of the chain. Lower grades of steel and/or various levels of material hardening can be found between the most expensive chains and the cheapest chains.

The truth is, each brand keeps its specific coating process a secret. You will often find the benefit of each treatment described in the road bike chain’s product description. For example, SRAM’s top-tier chains feature “Hard Chrome,” and it is described as being an expensive process that requires very stringent process control that will result in an extremely hard and wear-resistant surface.

While performance may not generally be affected by the chain’s coating and material, longevity is. The steel in bike chains is often hardened for wear longevity. A high-end coating can prevent rusting, thus boosting its corrosion resistance. Surface treatments like “Nickel Plating” and “Titanium Nitride Plating” are used for giving smaller parts of the chain a higher level of abrasion wear resistance, thus allowing it to retain its function over a long period.

Besides longevity, the goal of a chain’s treatment is to enhance marketing capability and aesthetics; this is great if you desire a good-looking chain, but in order to analyze its performance, we need to observe what is happening with the chain’s internal parts.

Manufacturing Tolerances

Tighter manufacturing tolerances and a more in-depth quality control process play a large role in the price as well. All of the factors that go into this process vary by manufacturer. Usually, manufacturers discourage cross-compatibility between chain models and drivetrain models, while aftermarket chain makers encourage it.

Whether you mix brands or not is entirely up to you. Usually, 8-, 9-, 10-, and 11-speed bikes are safe to mix-and-match brands according to their needs, as long as they stick with proper cog counts (a topic that we will cover in a later section of this article). Some people even prefer to pick a chain that is one speed higher than their drivetrain for improved durability and shifting.

If you are going to mix brands, be sure to cross-check compatibility between brands and models. Certain models are completely incompatible with other brands. An example of this is SRAM’s AXS Road, which uses a chain with an oversized roller.

The hardness of the chain can factor into the longevity of your road bike too. For example, SRAM generally makes their equipment “harder,” so its chains will wear out “softer” Shimano cassettes and rings very quickly. Inversely, Shimano chains are going to wear out much faster when paired with SRAM hardware.

Another factor in crossing brand models you may want to consider is shifting performance. Experienced cyclists say that this factor makes little to no difference. Still, it is worth noting that many manufacturers specifically design their chain plate shapes to best match their own shifting ramps. Certain cyclists can tell the difference, while others do not; this will all land upon your own personal preference.

What Size Bike Chain Do You Need?

Road bike chains can get complicated, and you will want to know what size to look for when selecting. Averaging up to 116 links, bike chains have more moving parts on them than any other bike component. One size does not fit all. Find a chain that matches the number of gears within your drivetrain.

Make sure that the chain’s length is long enough so that it can be shifted onto your biggest front chainring and the largest cog within the cassette without jamming. Do not make it too long, though, because you do not want too much slack in the smallest chainring and cog. A good way to find the perfect length for your new chain is to use your old chain as a guide.

Does Chain Size Affect Durability?

You may have heard that older drivetrains were more durable because of their wider chains. 8-, 9-, and 10-speed systems certainly have wider cog widths, and this allows for an increased surface area with the chain. But does this actually make the chains more durable?

According to a test done at Cycling Tips, this is no longer the case in newer drivetrain models. The following table illustrates the results they found:

ModelKMC Wear CheckerElongation Wear
Shimano HG40 8-Speed1000km900km
Shimano HG93 9-Speed1500km2100km
Shimano Ultegra 6701 10-Speed2100km2500km
Shimano Ultegra HG-701 11 Speed2400km2500km
Shimano XTR CM9100 12-Speed3100km4000km

As you can see, with each new gear that was added, durability increased. Granted, this test was conducted with Shimano chains, but there is a significant jump between the 8- and 9-speed models. Why do the test results reflect opposite conclusions from older models? As time goes on, manufacturers improve upon technology, processes are refined, and new low-friction coatings are implemented.

Sprocket Compatibility

The sprocket, or sprocket-wheel, is a profiled wheel with a set number of teeth, or cogs, that mesh with your chain. It is important to know the number of sprockets on your rear cassette because this correlates with how many gears you have. Sprockets vary between different “speed” cassettes based on the distance between the teeth.

For example, the gap on a 10-speed block is going to be wider than the gap on an 11-speed block. Because the gaps in higher speed transmissions are smaller, the chain for a road bike with that transmission needs to be narrower than a chain for a bike with a lower speed transmission. Keep in mind: all new chains come out of the box with more links than necessary. You will need to remove some in order to get the perfect fit.

Chain Wear Between Different Types

The whole reason you will eventually find yourself in the market for a new road bike chain is “chain wear,” otherwise known as “chain stretch.” Every minute that you spend pedaling, approximately 44,000 chain pieces are in constant motion; this makes about 320,000 individual instances of sliding surface friction. On top of all of this, your chain is close to the ground being exposed to the elements.

As the chain’s pins and links wear over time, the pitch, or length, of each link will grow. The pitch of a brand-new chain should rest at half an inch pin to pin; this is the standard that chainrings and cassette cogs are designed to function with. As “chain stretch” occurs and the chain pitch grows, it rolls higher on the tooth; this accelerates cog wear until it eventually rolls over the top, causing a horrible chain skip that can throw you off balance when you are not expecting it.

Using the Right Chain Lube

Budget chains that are made with lower-grade steel and minimum coatings tend to wear down faster. Premium chains with maximum coatings will certainly take a longer time to wear down, but how you handle and care for your bike can make all the difference. Using the right lube choice and careful maintenance can be the difference between your chain wearing out at 2,000km or 15,000km!

If your road bike chain is dry, then that friction is going to build up much faster. Lubrication aids all parts of your drivetrain. It helps prevent your rollers from rubbing and greatly reduces friction between the chain and cassette, crank rings, and jockey wheels. Keeping your chain clean and well lubricated is essential to extending its longevity.

All chains are made and used differently. Your chain’s longevity depends upon your choice of chain lube, your riding strength, shifting habits, the terrain you ride, and riding conditions. How long you go before changing your chain is entirely up to you. You do not want to change it too soon when your current chain is still good. But you do not want to wait too late and wear down other parts of your drivetrain. There are several different ways to measure chain wear:

  • The free method: This simple technique requires that you shift gears so that your chain is in the big ring and smallest gear available on the cassette. Pull the chain at the front of your chainring. Should your chain start to lift off the top, then the pitch has extended, and your chain is either wearing or worn.
  • Use a “KMC” Digital chain checker: This is a handy tool that allows you to measure a chain’s exact elongation; this allows you to change the chain on time so that you are not too early, and you are not too late.
  • Other methods: There are far more advanced and elaborate methods to check the wear on your chain. Much longer articles have been written on the subject that covers great detail on chain wear across different manufacturers and models.

Do Chain Price Points Make a Difference?

As we have mentioned above, the price of a road bike chain can have many different factors. These factors rely on longevity, durability, and efficiency. It is all going to come down to each individual’s preferences. One cyclist’s perfect chain could be the worst option for their neighboring cyclist.

Depending on the cycling demographic you find yourself in, your priorities are going to vary. If you are a racer, then you are probably looking for something with low friction. People who limit their cycling to weekends or casual commutes are most likely prioritizing running costs. There are some who fall in both categories who value both factors.

Is there really a difference between premium chains and budget chains? Lower cost chains are generally going to be made of lower grade steel. These chains likely have no surface hardening, no coatings applied, and no low friction treatments. Premium chains will have high-grade steel and are manufactured to higher tolerances. You will find numerous treatments like chromium carbide hardened pins and/or rollers, and a variety of low-friction coatings applied to a few or all of the chain’s working parts.

For non-racers, is it worth spending the extra on a premium chain? Or should you just stick with cheap chains and plan on replacing them more frequently? Racers certainly need premium chains, but casual cyclists should think twice before getting a cheap road bike chain. Consider these factors:

  • Remember that worn chains will wear out the entire drive train at a much faster rate: This could result in the necessity to replace more items even faster, such as your cassette and chainrings.
  • Casual cyclists are not often prone to check chain wear, or even know precisely what they are looking at: Your budget chains could result in a replacement of most of your drivetrain’s essential components.

Do low-friction chains and exceptional longevity go hand in hand? A premium chain with a low-friction coating will undoubtedly make your bike go much faster for a little while, but it will not last. The low-friction coating will eventually wear off, and the chain will function at the same level as a budget-conscious chain. Do not let this discourage you, though; there is a way to enjoy the benefits of low-friction without paying for low-friction coating.

If the premium chain you choose is equipped with surface hardening with higher-grade steel, then it is more likely to be lower friction all on its own. As long as you use a high-quality lubricant that is abrasive from contamination, then your chain can keep the benefits of low-friction while maintaining longevity.

Conclusion

Hopping on a bike and going gives you the freedom to soar about with ease and feel a gentle breeze on your face. Considering what chain to use on your road bike can be a daunting task. From brands to coating specifications, to manufacturing tolerances, to size, it is not as simple as picking up the cheapest option off the rack.

It is always a safe bet to match the chain with the manufacturer’s drivetrain. After all, the drivetrain manufacturer’s chain will continually be optimized to include the best shifting performance from your cogs. But sometimes the cyclist’s personal preference will influence cross-branding. Whether you are a weekend cyclist or an experienced racer, we hope that this article has helped you understand the basics of road bike chains.

Related articles:

Sources:

http://hub.chainreactioncycles.com/buying-guides/components/chains-buying-guide/

https://www.bikeperfect.com/features/best-chains-for-mountain-bike-gravel-and-road

https://zerofrictioncycling.com.au/wp-content/uploads/2018/04/Chain-Longevity-Testing-Full-test-brief.pdf

You may also like

Leave a Comment