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MTB
The ultimate buyer’s guide to mountain bike chains
Not sure which chain to get for your mountain bike or how to take care of it? Learn handy tips to get the most out of your chain.
From beginners to pros like Rachel Atherton, everyone who hops on a mountain bike needs to know the importance of chain maintenance — even if you’re not going to extremes like this Red Bull athlete.
It was business as usual for Rachel Atherton
© Bartek Woliński/Red Bull Content Pool
“I’m inspired by people who've pushed their bodies to the limit,” Atherton shared.
Proper bike function, including the chain, is a must for pushing the limits. As there are numerous bike-chain manufacturers, varying brands of drivetrains, and different numbers of gears on mountain bikes, buying the correct chain for your bike might appear to be a minefield. Fortunately, it isn’t quite as complicated as it might first seem.
This guide to mountain bike chains can help you make the right choice when making a purchase, as well as explaining how to replace the chain and take care of it.
01
Mountain bike chain basics
As a key part of the drivetrain, a mountain bike chain is responsible for the bike’s forward movement. Your pedals transfer rotational force through the chain, which then engages with the gears on your bike’s rear wheel. The chain also makes changing gears possible.
These essential components of a mountain bike chain help guide your buying decisions, no matter which types of mountain biking you plan to try out:
- Chain size: Longer chains are necessary to accommodate a wide range of gear changes. Similarly, a longer wheelbase requires a longer chain.
- Width: The fewer gears on your bike, the fatter the chain. The more gears on your bike, the narrower the chain.
- Material: Steel, titanium, and chromoly (a combination of chromium and molybdenum steel) are common.
- Coatings: You’ll often find mountain bike chains with anti-rust coatings and other kinds of platings to extend their lifespans.
- Compatibility: Double-check that your chain works with your mountain bike’s cassette and derailleur.
02
When should you replace a mountain bike chain?
A break isn’t the only way to tell it’s time to replace your chain
© Tom Webster/Creative Commons
It’s time to replace your mountain bike chain when it sustains obvious damage. It’s also a smart idea to keep an eye on your chain to ensure it stays in good working condition and that it hasn’t stretched out over time. Preventive maintenance is key for mountain bike performance, so consider regular chain changes if you use your bike a lot.
Sometimes, it is obvious that a chain needs replacing – smash it into a rock and bend a link out of shape, or snap the chain completely, and it is probably time for a new one. While it's possible to remove the broken section and refit the chain, it’s best to invest in a new chain afterward.
However, mountain bike chains and drive systems wear out and will need replacing after a lot of use. There is no set mileage limit on a chain as its lifespan can be affected by the conditions in which you ride, how much care you take of the drivetrain, and how much power goes through it.
There are some simple ways to check when to change a mountain bike chain though. If your gears start slipping and jumping regularly, this could be a sign of a chain on its way out. You can test a chain easily without any tools by flexing the lower section that runs between the bottom of the rear derailleur and the front chainring side-to-side. If the links feel really loose and rattly and the chain flexes considerably, it could be worn.
Specific tools like a chain checker are available to test the wear on a chain by measuring the distance between links. These are relatively inexpensive to purchase, but as you’ll need them very infrequently, it is probably best to pop into a local bike shop and ask them for an assessment.
Which mountain bike chain should you buy?
Most new mountain bikes are 1X and therefore only have 10, 11 or 12 gears
© Jannik Wüster/Unsplash
The type of mountain bike chain to buy depends on the type of bike you’re shopping for or you already have, how many gears it has, and your budget. The most important thing, however, is choosing a chain for the number of gears on your bike.
Most modern mountain bikes feature a 1X (‘one-by’) drive system, which means they use just one chainring at the front (as opposed to two or three that used to be common), and a wide range of gears on the rear cassette.
A lot of mountain bikes are 10-, 11- or 12-speed and, when buying a chain, it will be clearly labeled accordingly. Simply find out how many gears, or “speeds,” your bike has (count the number of gears on the rear cassette and multiply it by the number of chainrings at the front), and pick the corresponding chain.
03
Which brand of chain should you buy?
For best results, get the same brand of chain as your drive chain
© Kakadu / Flickr
For optimal performance, it's recommended to match your drivetrain manufacturer (the most common are SRAM and Shimano) to the brand of chain. This isn’t vital though – as long as the chain is made for your number of gears, it should work.
04
Can you mix and match drivetrain components from different manufacturers?
Yes, different brands of chain, chainring, crank, cassette, and derailleur can be used together. However, for best performance, it's recommended to match up components from the same manufacturer.
05
Which manufacturers make mountain bike chains?
Some major companies that make mountain bike chains are SRAM, Shimano, KMC, Wippermann and SunRace.
06
Should you replace the cassette when replacing a chain?
A dirty (and slightly worn) cassette
© Ben Wightman / Flickr
The rear cassette (gear sprockets) doesn’t always need to be replaced when changing a chain. If there is a lot of wear on the cassette (the teeth look worn down) then it should be replaced too.
07
Are there e-bike-specific chains?
Yes, e-bike-specific chains are made to cope with the extra power put through them by assisted pedalling.
08
How do you remove an old chain?
Most good multitools include a chain tool
© Dieter Laskowski / Flickr
The way you remove an old chain depends on whether your bike has a quick link chain or not.
If you’re removing a quick link chain:
- Locate the quick link on your chain.
- Identify the larger hole in the link where the pin can slide through.
- Use your fingers to push the two ends of the quick link toward each other while shifting the pin toward the larger hole.
- Grab a pair of pliers. Insert the nose of the pliers into the chain, mimicking the position of a chainring tooth.
- Close the pliers to push the quick link into its open position. Once the link is open, unclip the chain and remove it.
Specific chain tools split chains by pushing the joining pins out of links. You’ll typically find these in a multi-tool. If you’re using a chain tool designed to push the central connecting pin out of a chain:
- Position the chain tool over the chain, ensuring the chain sits correctly in the tool’s guide.
- Align the tool’s pin driver with the central connecting pin of the chain.
- Slowly turn the tool’s handle to push the pin out.
- Ensure the pin is being pushed out straight and not at an angle.
- Stop pushing before the pin is fully out. Leave it sitting in the outer plate so the chain can be reconnected if needed.
- Remove the chain once the pin is sufficiently pushed out.
09
How do you get your chain the right length?
Curtis Keene bike check: derailleur
© Marv Watson/Red Bull
The easiest way to decide what length the new chain should be cut down to is by measuring it against the one you are replacing. The process is the same whether your bike has a quick link chain or a regular one; both types need chain tools to customize its length.
These step-by-step instructions will help guide you:
- Take the new chain out of the package. New chains come longer than necessary so they can fit various bike sizes and gearing setups.
- Measure the correct chain length by comparing the new chain against the one you’re replacing. You can also wrap the chain around the front chainring and the largest sprocket of the rear cassette. Bypass the derailleur while doing this.
- Thread the chain through the derailleur and pull the two ends together between the derailleur and the bottom of the chainring.
- Check that the derailleur is under tension but not locked out.
- Use a chain tool or pliers, depending on the chain, to remove excess links. Avoid removing too many links so you don’t have to add them back later on.
- Make sure that when the bike’s rear suspension (if it has any) is fully compressed and the distance between the chainring and the rear cassette is at its longest. If the chain is too short, it’ll block the suspension from fully compressing and it will ultimately break.
10
How do you maintain your chain?
Keep your chain clean and your bike running smooth
© Denis Klero/Red Bull Content Pool
Before you take your bike out — let’s say, an ambitious trip through the Swiss Alps — it’s best practice to tune it up. Aside from increased longevity, a clean, well-oiled chain can make a noticeable difference to drivetrain performance, resulting in quieter, smoother pedaling and gear shifts, and reduced friction.
There are specific chain-cleaning tools available to help thoroughly clean mud, old oil, and grit from the chain by running it through a series of brushes and degreaser fluid. Muc-Off’s X-3 Dirty Chain Machine is an example of one such system. If you don’t have the budget for a specific cleaner, you can always use an old toothbrush and some basic degreaser to scrub the ingrained grime from the chain.
Once your chain is clean and shiny, don’t forget to lube-up. There are many options for good chain oil, including biodegradable green oils.
