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How to Fix a Bike Chain that Keeps Falling Off

how to fix a bike chain that keeps falling off

I tell you, the bike chain is one of the essential parts of your bicycle. It is actually the heart of the drivetrain that is essential in powering your bike forward and providing optimum shifting performance. That is why it can be frustrating for a bike chain to come off during your bike ride. It is usual for a chain to drop off once, but if it is a regular occurrence, there is a big chance of some mechanical problems that need to be fixed.

But how to fix a bike chain that keeps falling off? The key is to find the reason why it keeps falling off. Unfortunately, troubleshooting this issue can be a challenge with the many possible reasons to consider. The problem can be caused by many things which are related to the drivetrain system of your bike.

How to Fix a Slipped Bike Chain

For a one-speed bike, fixing a chain that keeps on falling off can be easy. All you have to do is loosen the nuts that are connecting the rear wheel and the bike frame. Once it is loose, you can slide the wheels back and make the bike chain tight. Then, you can bolt the wheels back down to the new position to make sure that the wheel is bolted down inside the frame.

However, if you are dealing with multi-speed bikes, we are actually looking for multiple reasons why the bike chain is falling off consistently, which is found on our list below:

The Drivetrain is worn out

If you have been consistently using your bike and feel that you have put up a thousand miles while experiencing constant slippage of the bike chain, it is probably that your drivetrain has worn out. You can look at the cogs’ teeth and check if it becomes hooked and shark-tooth looking. If it is, the best solution to fix the problem is to replace them. Replacing the individual cogs can be easy but buying a new cassette is more practical.

Stretched Bike Chain

If you have been biking consistently and already covered with good mileage, chances are, the chain has been stretched and the inner rollers already damaged. It is advised to replace the chain after 1000 to 2000 miles of pedaling since there is a big chance that the chain is already stretched. The stretched chain is also one of the reasons why the chain keeps falling off in your bike. Fortunately, you can use a tool called a chain checker that checks if the chain is already stretched. If it is, the best fix is to replace your chain with a new one.

The Bike Chain is Dirty

If your bike chain is so dirty and muddy, there is a big chance that it will not work perfectly and will eventually fall off. All of the dirt in any form can cause the components of your chain not to move well over the cogs. This situation will result in falling off the chain, especially on bumpy roads.

To fix this issue, you can probably use a degreaser to clean all the dirt and grimes, followed by putting oil on the chain. Another option is to apply chain oil and then use clean rags to remove all the dirt.

A Stiff Link

A stiff link can make the chain fall off in your bike, even if it is only one. This type of link will have a difficult time bending around the chainrings and the jockey wheel, which in turn causes the chain to fall off. You can put a chain oil to eliminate the stiffness, or you can use the chain tool to let the link loose.

how to fix a slipped bike chain

Worn out cogs teeth

If you have been using an old chain for some time and fail to replace it properly, it can damage the drive train components, particularly the cog teeth on the chainrings and the cassette. And the effect of worn-out cog teeth can continue even if you replace the old chain with a new one. So, it is necessary to replace the bike chain on time to avoid damaging the other related parts of the bike.

Wrong size of the bike chain

If you are using a new bike chain and it falls off, chances are, the size of the chain is incorrect. For you to check if it is the right size, you can compare it with the old chain and check its length. Since the old one is stretched and used, it should be longer compared to the new one. If the chain feels longer, you can have the option to remove a couple of links to get the proper length.

Please note that a chain with the proper length should reach the large-large combination of the gear. Also, the rear derailleur should not overlap itself when the gear is in a small-small combination.

The new chain and the drive train is not compatible

If you are using a new bike chain and it suddenly falls off, apart from the wrong size, the possibility of the drive train and the chain not being compatible can also be a reason. You do need to recheck the compatibility of the two since there are certain types of drive trains that only worked with specific bike chains. An excellent example is the 11-speed drive trains which are not compatible with the other drive chains.

There are still other causes that will make the bike chain keep falling off. For example, problems with the rear derailleur can cause the chain to fall off, such as being out of alignment, bent hanger, and failure of the clutch. You also need to clean the derailleur since it can also contribute to the falling off of the vaccine. Meanwhile, when the front derailleur is out of alignment or has shifted, it can also cause the bike chain to fall off.


Learning how to fix a bike chain that keeps falling off is an excellent skill to have as a biker. Ultimately, your bike will face some issues, such as the bike chain not working correctly and eventually falling off. If you learn how to find the real reason behind the problem, then it will be easy for you to fix it once you encounter similar issues in the future.

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