Why Does My Bike Chain Slip When I Pedal Hard?

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Biking is one of the best outdoor activities for anyone out there. If you’re someone who cycles often, you likely have encountered several bicycle problems that often get in the way of a peaceful bike ride, one of the main problems being a slipped bike chain.

Several things can cause a bike chain to slip. The most common reason for a slipped chain is the natural stretching of cables that comes with frequent usage of your bicycle.

Other reasons for your bike chain slipping can be having a relatively long chain that comes off too often or having a damaged derailleur that needs to be replaced. However, fixing a bike chain is not very hard.

This article will help you discover why your bike chain often slips while pedaling hard. Let’s get started!

Why Does a Bike Chain Slip While Pedaling Hard?

While many scenarios can lead to your bike chain slipping off as soon as you pedal hard, especially in situations likes when you’re switching gears while riding or pedaling hard, you can typically diagnose the problem very quickly.

The most common reason this will happen is when your bike’s cables are stretched too much due to natural usage. It’s just simple wear and tear of the wires after the cable has gotten old and has been used multiple times.

Listed below are some of the common reasons why your bike chain comes off while riding or pedaling hard. Most of them can be resolved quite easily. If you’re unable to repair it though, you can always contact a mechanic.

A Worn Chain

This is one of the most frequently occurring reasons for the chain to slip on the cassette. With regular use of a bicycle enduring high-intensity pedaling, the chain is subjected to higher levels of everyday wear and tear, having issues such as getting damaged or becoming stretched.

This wear causes the rollers to loosen their standard shape, and the plates get elongated. Eventually, the chain loses its mechanical contact with the sprocket teeth and starts causing frequent slipping to occur.

You can test the health or functioning of your chain by using a specific tool often referred to as a “chain wear checker” or a “chain checker.” These are available in multiple shapes and sizes, and each one is used in a particular way to help you gauge the amount of wear occurring on your chain.

Misalignment of Parts

This issue commonly occurs due to incorrect installation after switching to a new chain or a new cassette without correctly following the manufacturer’s directions.

It is advisable to pick any new drivetrain parts after becoming well informed about their compatibility with your bike and pre-existing parts. Not using well-matched components can cause the chain to slip or cause cracking sounds while pedaling.

Adding Excessive Lube

While adding lube is necessary for the smooth functioning of a bike chain, adding too much lube can make it even easier for the chain to slip over the sprocket teeth, especially when it has some stretch.

Too much lube can cause your chain and sprocket to lose the perfect level of contact that’s essential for the proper functioning of the chain.

Shifting Gears Problems

Bad shifting or shifting two gears simultaneously will also cause the chain to slip from one cog to the other. Doing so can also result in cracking sounds that will be made by the chain while pedaling.

Shifting problems are often caused by multiple parts of the drivetrain system, mainly issues with the rear derailleur.

Worn Out Cog Teeth

Cassette and chainring teeth can also be damaged after repairing or replacing a heavily damaged chain. Worn-out cog teeth can easily cause a chain to slip. Every time the chain gets stretched, it widens the space between the cog teeth.

It’s normal if you have one or two worn teeth on a single cog, but if you notice most of the teeth being damaged, it’s better to get the cassette replaced.

How Can I Fix a Bike Chain?

Since there are several reasons why your bike chain may not be performing well, it’s crucial to do a deep inspection and diagnose the issue before you begin actually trying to fix it.

To fix a slipping bike chain, you’ll need to repeat this process with each derailleur. Be mindful of the directions as they’ll need to be changed when you’re working with the left compared to the right derailleur.

Here’s how you can repair your bike’s chain:

The first step you need to take is to place your chain on the lowest cog and press the derailleur up to see if the bike changes up a gear.
If your bike doesn’t change up a gear, add more tension. You can do this by locating your barrel adjuster, which is most commonly found on the brake. Your bike’s cable passes through it as it enters your shifter.
Once you’ve located it, unscrew the adjuster by turning it a half turn away from you (for the rear derailleur) or towards you (for the front derailleur). You need to shift the cable down into the lowest gear and see how it functions when it shifts.
If it shifts perfectly fine, you’re done with the process. However, if it doesn’t shift properly, you need to repeat the process until it does work. When you notice the gear shifting correctly, continue moving through the gears in your cassette.
You’ll need to repeat the same process for your other derailleur, bearing in mind the opposite directions when unscrewing the adjuster.

This is one of the most common ways to fix or repair your bike chain that may be falling off due to any of the reasons mentioned above. However, if, after following these steps, you’re unable to resolve the shifting issues, it’s best to contact a professional mechanic.

Why Does My Bike Chain Make a Clicking Sound?

This issue is also commonly experienced by many cyclists. The clicking sound you hear while riding your bike is most likely caused by the chain rubbing against the derailleur cage.

There are two possible reasons why the bike chain makes a clicking sound.

The first reason is that your chain and derailleur may need lubrication. It’s common for old chains to undergo some wear and tear. For smooth and effective functioning and friction between the chain and derailleur, it’s essential to keep them lubricated.
The second reason is that you are changing two gears at once. That can make your chain jump up or down a gear on the rear cassette. It could just be your derailleur that needs some quick adjustment.

Are Your Derailleurs Bent?

While checking your bike chain for any wear and tear is essential, it’s also crucial to check for bent derailleurs, derailleur hangers, and bent cog teeth. All of these issues can be straightened out except derailleur hangers.

A bent derailleur is common for MTB riders caused due to heavy impact with continuous riding. However, it’s a safety issue that you can check for, as any form of heavy impact can cause the derailleurs to bend.

Frequently Asked Questions (FAQs)

1. Why is my new bike chain slipping?

Although it’s uncommon for new bike chains to slip, the underlying issue here could be that the stretched chain damaged the normal shape of the cassette teeth without showing any signs of slipping. So, when you replace a new shorter chain, it may not properly fit with the cassette teeth that the old chain has damaged.

2. Can I use WD-40 for my slipping bike chain?

It is not advisable to use WD-40 for bike chains as it is a de-greaser, and its primary function is that of a solvent or rust dissolver. It will not work well on drivetrains or gears of any type.

3. How do I know if my bike chain is loose?

You can find this out quickly when your chain starts constantly slipping off while shifting gears since the derailleurs can’t handle the extra chain length. You will need to shorten the chain length to resolve this issue.