How to Tighten Mountain Bike Chain

Knowing how to tighten mountain bike chain is important because this part makes your bike move. You can’t pedal your bike or go to different places if your chain isn’t working correctly.

There are also times when your chain loosens because of the stress it gets. A loose chain can even damage your drivetrain’s other parts!

In this article, we’ll teach you how to tighten mountain bike chain correctly. This saves you the hassle of fixing your bike when you’re out on the trails. You also don’t have to spend time and money on a mechanic because you can do it yourself.

Tools needed to tighten mountain bike chain

  • Socket wrench
  • Rag
  • Allen tool
  • Lubricant
  • Bike stand
  • Gloves
  • Outlet wrench adapter

Step-by-step guide on how to tighten mountain bike chain

Step 1

The first thing to do is to put your bike on a repair stand. This lets you easily check the whole drivetrain and see if there are other parts that need fixing. You can also find cracked or bent parts and fix them before tightening your chain.

Also, check the cogs and rear derailleur and see if they’re in the right shape. This is important, especially if you’ve just had a bad bike crash.

Then check the limit screws and see if they’re correctly adjusted. They shouldn’t be too tight or too loose. You might even have to replace them if they already have a lot of scratches.

Step 2

Look for the derailleur screw. Its exact location depends on your bike and drivetrain. But this can usually be found at the backside of the derailleur. There are also times when it has a letter B imprinted around it.

Use an Allen tool to increase your bike chain’s tension. You can rotate the screw in a clockwise position. Just don’t overdo it so it won’t be too hard for you to shift your gear. You can decrease the tension if the chain shifts so hard.

Step 3

It is now time to access the rear wheel. This is important because the chain is directly connected to your rear wheel via the cogs and hubs. This is also the reason you ensure that your drivetrain works properly before tightening the chain.

Gently lift the release lever found on the brakes of your mountain bike. This disconnects the hydraulic cable. Then slowly raise the quick-release lever. This lets you adjust the rear wheel and ensure that it’s tight enough for the chain to stretch correctly.

Step 4

Adjust your rear wheel. This improves your bike chain’s tension and ensures that it stays in place even if you ride on rocky trails.

Clean your wheel thru-axle using soap and water and then dry it using a clean rag or towel. Then apply a little grease around the axle. This lubricates the axle’s surface and makes it run smoother when you install it back. Then slowly slide the wheel thru-axle into the rear dropout.

Make slight adjustments on your derailleur’s limit screws. Turn it clockwise to tighten it. You can then turn it counter-clockwise to loosen it.

Don’t overdo the adjustments so that your chain won’t be stressed. Just make slight adjustments and try shifting the gears to see if the chain is tight enough.

Look at your bike chain and see if you already have the ideal tension. You can repeat the process until you get your preferred tension.

Step 5

Put everything back in place and make sure that all the parts are secured correctly. The last thing you want is a dropped chain. Or worse, is losing your wheel while riding!

Also, ensure that your quick-release lever is in a downward position. Reattach the shifter cables and make sure your wheels are aligned. The tires shouldn’t rub against your chain or bike frame while spinning.

FAQs on how to tighten mountain bike chain

How tight should a mountain bike chain be?

It should be tight enough that it can move around half an inch upward and downward. But sometimes your chain still slacks, even if you already tightened it. This happens if the chain has expanded.

This is normal because the chain links can stretch, especially if it’s used too much. You can change your chain and get a new one if this happens. Or you can remove a few links to get the right tension.

Does lubricating your chain affect tension?

Yes, it does. Lubricating your chain is important because this smoothens out the chain’s links. Regularly lubricating your chain also gets rid of rust. It can even slow down the wearing process.

This improves your mountain bike ride because you can pedal easier. Shifting gears also becomes smoother because the chain is in its right condition. Make sure your chainring, largest cog, front and rear derailleur, and axles are in place.

Is it better to replace your chain instead of tightening it?

This depends. You need to replace your chain if it becomes loose because it’s already old. But the downside is you’ll spend more. But you don’t need to buy a new one if it’s still new. Just tighten the chain, ensure the surrounding parts are correctly installed, and lubricate your chain.


Learning how to tighten mountain bike chain on your own is important. This saves you lots of time and money because you don’t have to go to the bike shop. You can also fix your chain easily when you’re out on the trail.

Just make sure you know the right technique on how to tighten mountain bike chain. Maintain your bike properly, service it regularly, and take good care of it. Doing all these will make you enjoy your mountain bike even more.

Related: How to Put a Chain Back on a Mountain Bike

How to Make a Chain Whip

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Jomar Teves
A writer by day, a tech enthusiast by night, and a mountain biker at the weekends. After four years in business school and working for multinational clients, Jomar believes he can improve the world through his writings. Jomar has six years of experience as a writer and has a degree in entrepreneurial marketing. Some of his works have been published on Blokt, Clutch Points, and iTech.