Bike Chain Skipping: Why It Happens and How To Fix It

When your bike chain is skipping, you can feel the difference in your ride, particularly when you are pedaling hard. The chain skipping can also lead to accidents and damage other parts of your bike, such as the rear cassette.

Bike chain that keeps skipping

Bike Chain Skipping

If your bike chain is skipping gears, the cable tension could be wrong, which in turn can affect the rear derailleur. Another common issue is old or worn-out parts. There are many different causes of skipping chains.

In this article, you will learn how to determine why your bike chain skips and how to use different tools, including a barrel adjuster, to fix it.

How Is the Chain Skipping?

A few different things can happen when a bike chain is skipping, and they point to different problems. The chain is either skipping gears as you move or skipping over teeth completely.

When a Bike Chain Skips Gears

Most cyclists experience a problem with their bike chains when trying to switch between gears. The chain will skip two gears instead of just one, or shift between gears even when you don’t make a switch. The most common culprit is a problem with the rear derailleur.

The rear derailleur is the gear system that moves the chain between sprockets when you shift gears. If your chain is not at the right tension, the derailleur won’t be able to do its job. If you notice a problem with the chain only when you switch gears, check the tension and the derailleur first, as this is the most likely culprit.

The tension and the derailleur, however, are not always the cause of skipping chains when switching gears. For more on troubleshooting this problem and how to fix it, keep reading.

When a Bike Chain Skips Teeth

If you’re noticing problems with your chain when pedaling normally, not just when switching gears, then your bike chain is probably skipping teeth entirely as it moves through the system. In that case, the culprit isn’t the derailleur but usually the chain itself.

Check the state of your chain, the cogs, and the teeth on your derailleur. If you see any worn teeth, or if any of these parts seem worn out or bent out of shape, repair or replace them.

Is the Tension Right?

Perfectly calibrated cable tension is crucial for helping your bike switch gears and ride properly. Often, the tension being off is the culprit for a skipping bike chain.

Your chain doesn’t need to be old or worn to lose tension. It’s common for new chains to need a few rides to settle into the right tension. Chains also naturally stretch as you ride, and you may need to readjust from time to time.

To check if tension problems are causing your chain to skip, put the bike in park and shift to the lowest gear (when the derailleur is in the lowest cog). Then press the shifter without moving the bike to see if the chain shifts into the next-highest gear. If it gets stuck, there is probably an issue with the tension.

How To Fix Your Tension

You can fix the tension on the rear derailleur using a little tool called a barrel adjuster. The barrel adjuster is a small part on the back of the derailleur right where the cable housing meets the derailleur. Turn it away from you to adjust the tension.

Bike chain that keeps skipping
You can see the black, cylinder-shaped barrel adjuster in the center of this photo.

If the barrel adjuster doesn’t fix the tension, try tightening the bolt at the place where the chain exits the derailleur, or check the limit screw.

Usually, these steps will solve any problems with the tension. If these steps don’t do the trick, your chain may be too long. You can cut off a few links and try again.

Are the Parts Old or Damaged?

An old or worn-out chain is more likely to skip or get stuck. Problems with other parts of the bike can also affect the way the chain works.

An Old or Damaged Chain

Many cyclists don’t know that chains have a limited life span. Chain wear is inevitable, and although a chain can last for thousands of miles, after too many rides or too many years the metal grinds away and stretches the space between the circle links. While you can maximize the life span of your chain by lubricating and cleaning the chain regularly, all chains have to be replaced eventually.

If you’re not sure if your chain needs replacing, use a chain checker tool to check the chain health.

Sometimes one of the links gets stuck or damaged, and therefore the entire chain doesn’t need complete replacing. In that case, you can manually unstick the chain link or replace just that part of the chain.

Cable Housings

The cable housings are casings that help different cables move throughout the bike. Sometimes these housings pick up rust and debris that cause the chain and cables to get stuck.

Bike chain that keeps skipping
The cable housing next to the chain can sometimes get too dirty.

If the housings are designed to have lube, go ahead and lubricate the housings regularly with chain oil or chain lubricant and be vigilant about rust.

Be careful not to lubricate the parts too much, since too much chain lube absorbs dust and debris from the road and wears out your parts.

Derailleur

Sometimes the problem involves damage not to the chain itself but to the derailleur. With wear and tear, some of the derailleur hangers get bent. This is common on mountain bikes where the derailleur gets bumped out of shape on rough types of terrain.

You can sometimes bend the derailleur parts back into shape with an alignment tool, but your best bet is to replace the part completely. You should also check the cogs along the part to see if any are bent out of shape.

Do You Have the Right Chain?

If your chain does not fit along the rear cassette properly, it could lead to skipping.

There are a few reasons behind poor fit. One is the new Boost technology that widened certain parts of a bike. If you’ve had one part replaced that is wider but the other hubs and chainrings weren’t adjusted to compensate for that, your chain can slip.

Chain compatibility is also important. If your chain is too long or not the right width, it will have trouble fitting on the cassette properly. Fit issues are most common when people mix speed chains and cassettes that have different numbers of gears. With some adjustments this can give you a smooth ride, but you have to be very careful, or your chain could get stuck.

Handling a Stuck Bike Chain

A stuck bike chain when you’re trying to shift gears is annoying, but usually fixable. The most common culprit is an issue with the cable tension, which you can fix by adjusting the barrel adjuster and making sure that you use the right chain for your cassette.

If adjusting the tension doesn’t work, or if your bicycle chain is skipping teeth completely, there may be something seriously wrong with your bike, such as an old or worn chain.

If you ultimately need to replace your chain, make sure you know how to find the master link on your bike chain so that you can remove the old chain.