How Often Should You Change A Mountain Bike Chain


Knowing how often you should change the chain on your mountain bike can involve a little trial and error the first couple of times you do it. If you wait too long you can potentially damage your cassette and even your chainring so it is always better to do it sooner rather than later. While some of this of course depends on the amount of actual riding you do and over what terrain you are biking on, there are a few tests you can do to try to determine if it is getting close to time.

So how often should you replace your mountain bike chain? You main indicator that you should replace your chain is when it starts to stretch. While there is more than one reason why a mountain bike chain might need to be replaced, the most common reason is probably due to stretching. Over time your chain will stretch as the pins that hold the links of the chain together get worn down and allow the links to move further apart. Though a little of this stretching is okay, if your chain is starting to slip while you are on the trail or switching gears then you have probably waited longer than you should have to change it out.

Other things that are clear indicators are that it slips into the wrong gear or even that it drops the chain altogether. If you have been riding mountain bikes for a while you may even notice subtle signs that it takes a moment longer than usual after you apply pressure to the pedals before the chain actually starts moving the wheels and this is also a sign.

The first test that that shows if your chain has stretched too much requires you to have your gear set to its biggest gear and to pull on the chain around the chainring with your fingers. If you can see that you can pull it away from the chainring and get a gap – even a small one – between the chainring and the chain then it is getting too loose.

Another option is to measure the chains with a ruler or tape measure, making sure that whichever one you choose you can hold it steadily. Put the end at the dead center of one of the chin pins and then look at the 12” mark. This should be at the dead center of another one of the chain pins further down.

If the 12” mark of the ruler is about 1/8” too short to reach the center of the link then it is time to replace your chain. If it is less than that then you could probably keep going a little while longer. However, if it is more than that then you might need to replace your cassette as well. If you find that you can’t keep your ruler quite still to get the measurement, or are afraid of doing it wrong, then there are chain measuring tools that are specifically for doing this and which can make it easier.

However, if you are not technically inclined at all the easiest solution is to replace your mountain bike chain every 800-2,500 miles. If these trails are really hilly and if you are going through sandy or muddy terrain, then you would replace it when closer to the 800 mile mark, and if you are mostly going on smooth and level terrain then you can take it to the 2,500 mile mark or even more if you care for it properly.

Riding in muddy weather and/or not cleaning your bike can make the stretching worse if it gets into your chain and works its way in between the chain and the cassette and forces the chain to stretch more. The same can be true of riding in areas where there are lots of tiny rocks.

While this cannot always be helped if the weather is bad, it is important that you clean your bike as often as needed in order to lessen the effects as much as possible. Cleaning it as soon as you can after a mud-filled ride is something you should never put off.

You should also clean your chain and lubricate it regularly to prevent it from rusting which, if it gets bad enough, can also be a reason why a chain might need to be replaced. This, as well as corrosion, can cause you to get “tight links” which is where the pin in the chain link won’t let it move properly and stiffens the joint.

If your mountain bike chain gets too many tight links or gets too rusted or corroded then it is an obvious sign that it is more than time to replace it. Even though a rusty chain may not have been used for 500 miles it will still need to be replaced if you can’t get all of the rust off of it.

Sometimes a link in your chain can become bent, either due to colliding with something or another reason. While that link might very well be able to be bent back into shape, allowing you to keep going with it, you should at least remove that link if possible. Also, go ahead and get a new chain and carry it around as a precaution since it will be far more likely for the chain to break at that spot if you can’t take that link out.

How To Care For Your Mountain Bike Chain

The chain of your mountain bike is perhaps the part of your bike that gets the most wear and tear and therefore it is always good to care for it to help it last as long as possible. One of the ways that you can do this is by lubricating it and cleaning it regularly.

While this should be done after every ride in muddy or dusty conditions, it is also good to do this every couple of months even if you are only riding your bike on smooth roads. If you notice that the chain links are noisy or that they tend to want to bind up on each other, or even if they just seem dry, then it is no doubt time to clean a re-lubricate them.

When lubricating your chain always use a lubricating oil that is specifically for bike chains. Motor oil is too thick to get into the chains well while household lubricating oils are too thin to do the job. As for vegetable based oils, they will do little besides making your chain sticky. Using the wrong lubricant on your bike will also encourage rust, so it is really best avoided.

There are two main different kinds of bike chain lubricant: dry, and wet. If you ride mostly in dry conditions with a lot of small dust particles and/or dirt flying around your mountain bike then you should go with a dry bike lubricant since the dirt will not be able to stick to it as much and will be a little easier to clean. However, this kind does not keep out water very well, tending to be washed away altogether, and so will let your chain rust if you ride in the rain a lot.

If you will be riding your mountain bike in a lot of wet weather then you should go with a wet bike lubricant since this will keep out the moisture better. But this should not be used for dry conditions since it will catch every particle of dust that gets thrown at it.

In order to lubricate your chain the first thing you have to do is make sure that it is clean. First set up your bike so that it is held steady, either by putting it upside down or in its stand, and make sure that you are working over newspaper or concrete just in case you drip some off the lubricant. If your chains seem to be pretty clean then all you might need to do is rub them down with a rag.

However, you may have to use a degreaser or solvent such as WD-40 if the lubricant has caught a lot of dirt. For really dirty chains there are chain cleaning tools which can be helpful, but most of the time a rag and a toothbrush will work just fine. Do this to clean the entire length of chain.

You will always want to wait until the degreaser has dried and then you can re-lubricate the bike chain, making sure to wipe any excess lubricant off when you are done so as not to catch more dirt. Do this by placing the lubricant on the inside of the chain, turning the pedals slowly as you do so in order to work it in and shift through all of the different gears so that the chainring and cassette are lubricated as well.

Also, you do not want to lubricate your mountain bike chain right before you go for a ride. This is because the lubricant actually seeps in a little over an hour or two and if you ride too soon afterwards then you will not give it a chance to seep in thoroughly and will instead end up slinging some of it off the chains.

Every few cleanings you should do an extra thorough cleaning and re-lubricating by taking your chain off of your bike and soaking it in chain solvent. Brush it thoroughly, soak, and brush it again to get every particle of dirt off and then let it dry. Once it is dry re-install it and lubricate it as usual, taking the time while it is off to do a thorough cleaning of the cassette and the chainring as well.

The other important thing to do to care for your bike chain is to try to keep it as free from rust as possible. If you do mountain biking in an area where there is snow then odds are you will end up with salt landing on your bike due to the salt that is poured to keep the ice at bay. Salt really likes to rust your bike chain and is the reason why some rusting during the winter can be unavoidable if you ride at all.

However, you should do your best to make sure that this rust does not accumulate on your chain or it can cause problems. Rust is much easier to get off if you don’t wait for it to build up, so this should be done regularly. For small amounts of rust you can moisten something abrasive like a steel scouring pad with something acidic like lime juice and scrub the rusty areas.

If there is too much rust to get off like that then the whole chain should be taken off of the bike and soaked in either lime juice, lemon juice, or citric acid for an hour to thoroughly moisten the rust. Then take it out and sprinkle baking soda on the chain as you scrub it with something abrasive. Once you have it all off you can rinse it well with water, let it dry, then re-install and lubricate it like normal.

Reasons Why It Is Important To Change Your Mountain Chain

Not changing out your bike chain when you are supposed to is a very bad thing, not only for your bike but also for yourself as well. At first it will only slow you down as the pins of it get further apart, costing you more energy for the same amount of power you used to be able to get. Then, it will start eating away at your rear cassette in particular which will eventually mean that you will not only have to replace the chain but the cassette as well, costing you more money.

If you take care of your bike well then your cassette can last through a dozen chains before it will need to be replaced as well. If you want to “wear it into the ground” however, deciding that you will just replace that too, then you risk not only the chain breaking but you could also shear the teeth right off of the cassette if you take it too far.

If you are going at a fair amount of speed when this happens then you could potentially be thrown right off of the bike. This could be really dangerous if you are mountain biking by a cliff or any other precarious spot, not to mention it might cause anyone riding behind you to crash into you and get hurt themselves.

If you were to try to put a new chain on a worn cassette the chain would be likely to slip off of it because the teeth of it have become worn down to points instead of being the right shape to grip the chain properly. Occasionally the chainring itself will also get worn and will cause the same problem, but you can lengthen the life of both by replacing your chain on time.

What Size And Type Of Chain To Use

When replacing your old chain with a new one it is vital that you get both the chain type and the length of the chain correct. The first thing you will want to do is to count the gear sprockets on your rear cassette – if you have a one-speed bike this will be one. This is because the greater the number of gears the thinner the chain will be in order to shift through them.

Contrary to what most people might think, the amount of space from one pin to the next and on the inside of the chain stays the same, the only thing that changes is the with as a whole as the walls of the connectors are thinner to fit in between more gears. This means that on the inside a 10-speed bike chain might fit a 9-speed bike, but it will have some slight problems when changing gears and this can wear certain parts of it faster, so it is always best to use the correct bike chain for your bike.

The internal width of the chain can also vary between 1/8” and 3/32” wide, though in a pinch the 1/8” wide will fit either. Still, it is not advisable to do this as you can potentially break the pins. As a general rule most single-speed bikes and ones with internal gearing come with 1/8” wide chains while mountain bikes that have more than three gears have the 3/32” wide chains.

While of course not every bike is going to require the same length of chain, it is very important to get the length right. If the chain that you install is too big then this will create problems and might leave you unable to use any gear that requires the use of a large chainring and a small rear cassette. If, on the other hand, the chain is too small then it can pull the rear derailleur out of its proper place which is really bad for your bike if you ride it like that.

In order to make a chain fit properly you should do one of three things to make sure that is the right length. The first way is to pull the chain through the drivetrain and loop one end around the cassette and the other around the chainring at the smallest gear setting, pulling it tight at the bottom. See where they come together and remove all extra links.

The second way is to take the chain and loop it on the largest chainring at the front and the largest cassette on the back. You do not put it through the derailleur, but instead pull it tight to wear it meets and then add two links to that. This should be the correct length for your bike and you can then disconnect the chain there and install it.

The last way you can do this and the simplest is, if you got a new chain that had exactly the same size links as your last one, you can count the links that are in your old chain and then count out the same number out of your new chain and disconnect any extra.

How To Change Out Your Mountain Bike Chain

The first step when changing out your bike chain is always to secure your bike so that it won’t move around or anything while you are working. The simplest way to do this is to turn your bike upside down so that it rests on the handlebars and seat with the wheels in the air, but you can also set it up on a mounted bike hook on the wall if you have one and find that more convenient.

Before you actually get to work it is advisable to have everything that you will need handy, and you should also consider taking some quick pictures of the chain first so that later on if you can’t remember how something went you have something you can look at to help you.

Next you want to disconnect a link on the chain. You can make this easy by checking your chain for its “master link”. This is not necessary and not every chain even has one, but if it does it will be a link that looks different from the rest. If you do have one of these then push the pedals so that it is suspended and not on top of either the cassette or the chainring.

If you do not have a master link then you will need a chain tool. Put a nice area of the chain in the suspended area where you can work on it, since if a part of the chain is damaged it might be harder to work with. Also, make sure that you have the right size chain tool since these can come in different sizes.

When you have a master link on your chain you should be able to simply grab the links on both sides of it and push them inward so that the master link is popped out of place. However, if this is too hard or it is jammed too tightly then you might need some master link pliers that are made specifically for doing this and give you better grip.

When you are using a chain tool, on the other hand, you will need to align it with the hole of one of the pins on a chain link. Screw the chain tool in, making sure that you keep it straight so that it will push out the pin on the other side. Keep going until you hear a pop or a click.

If you are going to be throwing the old chain away you can feel free to push the pin all the way through but, if you plan on keeping it as a spare or for any other reason, then it is not advisable to do this since it can be almost impossible to get it back in again right. Instead you should go to the other side of the chain and screw in the pin on the other side of the same link until it pops.

This way you will have two pins on opposite sides of the same link both pushed halfway through, allowing the chain to disconnect but allowing you to put the chain back together if you wanted to. Once the chain is disconnected it should be able to be pulled out of/ off of your bike. Then you should take the time to clean the different gears of any extra lubricating oil while there is not a chain in your way, using a degreaser to get rid of any build up you may have been unable to get to.

Once you have that done and are ready to attach the chain after making sure the length is right, put the new chain in exactly the way that your old chain was. Now is the time when looking at a picture of how your old chain was might come in handy. It can be easier to insert the chain if gravity is working with you, so place the part of the chain that is higher first followed by the sides so that it can stay in place without you having to hold it.

Next, attach the chain together using a chain tool to push the pins through the holes if needed. You should hear a click or a pop when it is properly in place. Then turn the pedals so that the chain goes all the way around at least once and keep an eye and ear out for any slight catches that might indicate that a loose pin is poking out somewhere.

If you see any of these then fix them with the chain tool and check again, now being a good time to give your chain its first lubrication while you are going over it. Then you can turn your bike back right side up again and take it for a short ride after which you should check your chain one last time, but then you are good to go!

Mike Rausa

I'm a 42 year old married father of 3 that fell in love with mountain biking late in life. Mountain biking quickly became my go to fitness activity. I created this blog to help beginners to advanced riders with tips and strategies to improve your riding experience. More About Me... https://mountainbikinghq.com/mike-rausa

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