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How to Tighten a Bike Chain

Whether you’re hitting it hard on dirt terrains or boosting huge in the park, your bike chain is an important part of your bike’s drivetrain. Bike chains loosen when you use your bike regularly, or the chain will detach from time to time. However, this doesn’t mean that anything is wrong with your bike.

You should not haul your bike off to your local shop just to spend your hard-earned dollars. With the right tools, you can tighten the chain yourself.


Tightening a Bike Chain on a Single Gear Bike (e.g., BMX)

If you’re new to the cycling world, you may wonder what a single-gear bike is. This bike comes with only one gear; it has a cog instead of a freewheel mechanism in the rear wheel.

Tools You Will Require to Tighten a Bike Chain on a Single Gear Bike

  • A bike stand or a surface where you can place your bike upside down
  • A socket wrench
  • A rag
  • High-quality bike lubricant
  • A pair of glove

The Steps

Step 1: Place your bike in the right position

If you’re an expert in bike chain tightening, you can do this with your bike standing right-side-up. However, it’s advisable to turn the bike upside down so that you can access the parts easily. Use a soft surface to avoid scratching the saddle if you don’t have a bike stand.

Step 2: Loosen the rear axle

To adjust your bike chain, you need to loosen the nuts holding the tire to the bike. Use a socket wrench and turn the nuts in an anti-clockwise motion.

Step 3: Pull back on the rear tire

This is the point you will increase your chain’s tension. Pull the rear tire carefully until you achieve the desired tension. You should do it very slowly to avoid snapping the chain. Ensure the tire is centered in the wishbone to make tightening it back a breeze.

Step 4: Ensure you have the right chain tension

You should be able to move the chain half an inch in both directions. If it moves too far in both directions, it means the bike chain isn’t tight enough and should be readjusted a bit more on the tire. However, if the chain is too tight, you’ll be unable to turn the pedals, so ensure you do everything right.

Step 5: Tighten the rear tire

If you’ve achieved the right tension, lift the rear tire and replace the axle nuts. Use the socket wrench and ensure the nuts are tight enough.

Step 6: Test the tire and chain

Spin the bike tire to check if it’s moving properly and doesn’t come in contact with the frame or chain when in motion. Test the chain and ensure it’s moving with ease about half an inch both ways. If the chain and tire work perfectly, your bike is ready to hit the road.

Tightening a Multi Gear Bike Chain (e.g., MTB)

Tightening a multi-gear bike chain is more challenging than a single-speed BMX. Here’s how to fix a multi-gear bike chain.

The Steps

Step 1: Place the bike in the right position

Put your bike upside down on a bike stand to help you access the derailleur and tire. If you don’t have a bike stand, look for a soft surface that won’t scratch the handlebars and saddle.

Step 2: Locate the derailleur screw

Most multi-gear bikes have a screw at the back of the derailleur. To increase your bike’s tension, turn this crew clockwise in a tightening motion.

Step 3: Access and adjust the rear tire

Disconnect the brakes from the cable and lift the brake lever to access the rear tire.

Step 4: Adjust the rear tire

To increase the chain’s tension, slide the wheel axle toward the rear dropouts while making small adjustments. After every adjustment, lower the brake lever and check if you have the right tension.

Step 5: Put the bike everything together

Once your bike chain has the right tension, put everything together and ensure the derailleur screw is well-fitted and tight enough. Ensure that the tire is spinning properly and isn’t in contact with the chain or bike frame.

Bike Chain Maintenance

There are several reasons why a bike chain may become loose. Some are related to maintenance, while others are caused by the type of riding. Unlike single-speed bikes where chains loosen from disassembly or crashes, multi-gear bikes lose tension due to maintenance issues and component wear.

The teeth on your derailleurs and chainrings wear down quicker than you’d expect. Water and dirt rubbing against your chainring teeth can break the plastic and metal fast. Before shortening the bike chain, check if your chainring and derailleur need replacement.


How Tight Should a Bike Chain Be?

Your bike chain should move about ½-inch in both directions. If you’ve followed the steps outlined above and the chain has some slack, it means the chain has expanded and may need adjustments to achieve the right tension.

Does Lubricating the Chain Affect its Tension?

Yes. If you don’t lubricate and clean the chain regularly, it will rust and wear away and become slack more often. A well-lubricated chain will last longer and make it easier to ride your bike.

How to Tighten a Bike Chain

Related: How Long Does a Bike Chain Last?


Over time, your bike chain will become loose or even off, so don’t rush to a bike store for a new bike. You can easily tighten the bike chain and hit the road in no time.

If you’re not sure how to tighten the bike chain, use the manufacturer’s guidebook or take it to a reliable bike shop.