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The ultimate guide to mountain bike chains
Not sure which chain to get for your mountain bike or how to take care of it? Follow our handy tips to get the most out of your chain.
There comes a time in every mountain biker’s life when it’s time to change your bike’s chain. But what mountain bike chain should you get? And how do you install and take care of it once you’ve found the right one?
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 will help you make the right choice when making a purchase, as well as explaining how to replace the chain and take care of it.
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
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 is possible to remove the broken section and refit the chain, it’s best to invest in a new chain afterwards.
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.
If your gears start slipping and jumping regularly, this could be a sign of a chain on its way out
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 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
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.
Some manufacturers have lots of different price-point options that come with all manner of fancy names, but choosing the right chain is simpler than it seems. The most important thing is choosing a chain for the number of gears on your bike.
A lot of mountain bikes are 10-, 11- or 12-speed and, when buying a chain, it will be clearly labelled accordingly. Simply find out how many gears, or ‘speeds’, you 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.
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 is 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.
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 is recommended to match up components from the same manufacturer.
Which manufacturers make mountain bike chains?
Some major companies that make mountain bike chains are SRAM, Shimano, KMC, Wippermann and SunRace.
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.
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.
How do you remove an old chain?
Most good multitools include a chain tool
© Dieter Laskowski / Flickr
Specific chain tools split chains by pushing the joining pins out of links. But some chains don’t need any tools in order to be removed – a ‘quick link’ can be split by hand or non-specific tools.
Splitting quick links is quite self-explanatory – you push the pin towards the bigger hole and then unclip the chain – although it isn’t always easy. A pair of pliers can be used to help push the two ends of the quick link towards one another. Insert the nose of the pliers into the chain, in the way a chainring tooth would insert itself when the chain is on it, then close the pliers to help slide the quick link into its open position.
Don’t push the pin completely out of the chain — leave it sitting in the outer plate so that you are able to refit it should you need
Most decent multi-tools have a chain tool included. The chain tool is used to push the central connecting pin out of a chain. Make sure to align the chain on the tool’s guide (which helps hold the chain in place) and ensure the pin is being pushed out straight from the side with nothing going off-line. Don’t push the pin completely out of the chain — leave it sitting in the outer plate so that you are able to refit it should you need.
How do you get your chain the right length?
Quick links can be handy for maintenance, but they don’t eliminate the need for tools when changing a chain. You will still need to use a chain tool to shorten a new chain out of the box, as all chains come too long so that they can be adapted to different sized bikes and gearing setups.
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.
At the correct length, the derailleur should be under tension without being locked-out, so conservatively take out the number of chain links needed to achieve this
If you snapped the old one and lost it on the trail, you’ll need to install the new chain around the front chainring and the biggest sprocket of the rear cassette. Then, after threading it through the derailleur, pull the two ends together between the derailleur and the bottom of the chainring.
At the correct length, the derailleur should be under tension without being locked-out, so conservatively take out the number of chain links needed to achieve this. Try to avoid going too short – it’ll be difficult to add links in afterwards.
Once you have refitted the chain, 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, that the chain isn’t too short. If it is, it’ll block the suspension from fully compressing and ultimately it will break.
How do you maintain your chain?
It's easy to keep your chain clean and well oiled to prolong its life
© Muc-Off
Going back to basics, if you want to get the most out of a mountain bike chain, the best thing you can do is to properly maintain it in the first place. Aside from increased longevity, a clean, well-oiled chain can make a noticeable difference to drivetrain performance, resulting in quieter, smoother pedalling 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. Good chain oil is inexpensive and there are many options, including biodegradable green oils. To find out more about caring for your chain, and other areas of your bike, check out our guide to mountain bike lubes below.
