Why Does My Bike Chain Slip When I Pedal Hard (SOLVED!)

It’s pretty frustrating if the bike chain slips when you are climbing up a steep slope or trying to accelerate the bike’s speed. Unfortunately, this can happen to any bike, even if it’s brand new.

Wrong gear indexing, improper cable tension, worn chain, and cassette, wrongly adjusted or stuck cable, worn cog teeth, and too much lube are some of the major reasons why the bike chain slips when you pedal hard.

You need to find the exact reason why the chain is slipping to solve the issue. In this piece, we will look at different reasons why does my bike chain slip when I pedal hard and how to solve them. Let’s go!

Common Reasons for Bike Chain Slipping

The chain of your bike can slip for multiple reasons. Sometimes only one reason is enough to call it a day. Let’s dive deep into the common issues that may cause the slipping problem.

Gear Indexing Problem

A simple issue can be the drivetrain that needs a bit of indexing readjustment. This is found in brand-new bikes, as well, as it’s not a major problem.

You can use a barrel adjuster to fix this problem. Other solutions may be readjusting the tension of the cable or reindexing the bike gears as per the default setup of the bike maker’s manual.

Cable Tension Issue

If the cables are stretched over time and not taken proper care of, there’s a possibility that it can cause the chain to slip. Over time, you may find corrosion on the cable area and higher friction is a common phenomenon, as well. This causes difficulty in gear shifting and causes skipping when you pedal hard.

You need to take your time at regular intervals and adjust the cable tension and loosen it up a bit. This way, it will not stretch when you are pedaling hard, thus will prevent skipping.

Stuck Cables

Sometimes, even if you’ve adjusted the chain tension, you will still find the cable to malfunction and cause chain slip. This is because the chain can get stuck in the cable housing.

The best solution for this is to pull the chain out from the cable housing and apply lubes to it. Try lubing the cable housing, as well. Doing this regularly will keep the chain moving smoothly.

Worn Out Bike Chain and Cassette

One of the prime reasons for bike chain slipping is the worn chain and cassette. If you are a regular biker, it’s possible that the chain and the cassette can get damaged earlier than you would expect. You need to run a thorough check-up to find if the chain and cassette are worn out or not.

In this case, you need to replace the chain and the cassette. If both are damaged, you should consider replacing both at the same time to avoid further damage to the new part.

Bent Teeth on a Cog

When you shift the gear, the chain goes out of the placement it has with the derailleur. If the Cog has a bent tooth, there’s a possibility that the chain will skip.

There’s no straightforward troubleshooting for a bent tooth or bent Cog. Even if you try to straighten the teeth by force, they won’t return to their original position. For bent cogs, if you can straighten it enough, you may make it work to some extent. Otherwise, a replacement is the best solution here.

Other Worn-out Parts

Apart from the chain and the cassette, multiple other parts like derailleur pulleys and outdated shifters can be the cause of chain slipping. Clogged dirt in these parts can compromise the performance.

If possible, you need to replace the parts or run a thorough clean-up process to make sure these are performing better.

Bent Derailleur

Another common problem is a bent derailleur, found most commonly in mountain bikes. The derailleur hangers can get bent easily over time. This bent causes the smooth movement of the chain, and you get slipping issues when you pedal hard.

The only solution here is to replace the derailleur with a new one.

Incompatible Drivetrain Parts

If you are installing cassettes and chains without following the proper guideline of the manufacturer, there’s a chance that the parts won’t be compatible enough. Then again, if you have used a replacement part, you must ensure that the parts are compatible with the design of your bike’s structure.

Overly Used or Underused Lube

Sometimes, using too much lube can hurt. This makes it pretty easy for the chain to skip while shifting gears. So, even if you are pedaling gently, there’s a great chance that the chain will slip from its place.

The opposite is also quite risky. If you use insufficient lube, it will make it harder for the chain to shift its place while shifting gears. Hence, chain slipping can occur. So, always try to lube moderately.

Old Sprocket

An old and worn-out sprocket is also to blame if the chain is slipping. You need to check if the sprocket got old or damaged over time. If yes, then replace it.

Proper Chain Size

The chain should neither be large nor small. If it’s larger than required, you will find pedaling resistance that may cause slipping. On the other hand, if the chain is too small, it won’t be able to get enough grip on the drive sprocket. So, check the manual and make sure you are using the right chain size.

Shifting System Issues

If the shifting system of your bike has some issues, then chain slipping is going to be a natural phenomenon for you. In order to check if the total shifting system of your bike is performing great, you need to check the following.

• Shifting cable: You need to check the tension.
• Rear Derailleur: Check the alignment of it.
• Derailleur Hanger: Check for the derailleur hanger if it’s bent or broken
• Bad Shifter: Check if the shifter is of low quality. If yes, then change it immediately.

Read Also: How To Change A Bike Chain Without A Chain Tool?

Final Words

So, now that you know why your bike chain slips when you pedal hard, it’s not going to be a difficult case to solve. We know it’s a painful issue to deal with if you are in the middle of a ride, but if you know the proper reason behind it, it’s no big deal. Keep a set of tools with you in your backpack. This will always come in handy when you find that the chain is slipping.

Have a great ride!