How to Tighten a Chain on a Dirt Bike [Step By Step Guide]

Learning how to tighten the chain on a dirt bike is essential to keep you safe and save you time and money. The procedure doesn’t take long, and you only need a few tools.

In this guide, I outlined the steps to help you tighten a chain on a dirt bike. You’ll also learn how to clean the chain to keep your bike running more efficiently.

I’m a motorcycle enthusiast, and I’ve been servicing my dirt bike for several years to keep it in top condition. Adjusting the chain is just part of the maintenance, and I can help you learn how to tighten a chain on a dirt bike. 

How to Tighten a Chain on a Dirt Bike 

First, check the chain block alignment to set the chain length. Secondly, loosen the rear axle nut and the tensioning bolts/locking nuts. You can then start to tighten the chain by turning the adjusters clockwise.

Make sure you use the proper tools to complete the work more efficiently. With the correct adjustments, the chain slack should be around 1.5 inches. You can usually check slack using a ruler.

Tools to Tighten the Chain on a Dirt Bike

You will need a few essential tools when tightening the motorcycle chain. Here is a list of tools you will need; some are compulsory, while others are not. 

• • Wrench set (10 mm and 12 mm open-end wrench) for loosening the locking nuts on the adjuster bolt.

• • 32 mm wrench or 250 mm crescent wrench for the rear axle nut.

• • Torque wrench to loosen the axle bolt.

• • Chain alignment tool or a ruler to ensure you have the right dirt bike chain length.

• • Bike stands to hold your bike and ensure the rear wheel rotates freely. Though it is not a requirement in adjusting the chain, it will make the process way more manageable.

• • A rag or a piece of cloth for creating tension on the chain for solid contact when re-tightening the axle lock.

• • A pair of gloves for convenience, so you don’t get your hands dirty.

• • Chain cleaner and chain lubricant – These are not 100% necessary. But they are handy for overall chain maintenance to keep it working more efficiently.

• • Flat surface – You will need a flat workspace, such as street parking, a driveway, a floor, or a garage.

Tighten a Dirt Bike Chain [Step-by-Step Process]

Tightening a motorcycle chain is a skill every biker should have. A loose chain may skip some sprocket teeth, causing uneven power distribution to your bike. The irregular power may result in dangerous revolutions. 

Chain tightening is a straightforward procedure you can complete in just a few steps. You will soon realize that you do not need to be a motorcycle specialist to tighten the chain. 

Planning

Before you start to tighten your dirt bike’s chain, do some research about how to do it and look for the tools needed, and organize them in the order you need them. A well-organized set of tools will save so much time when tightening the chain. You do not want to look for the tools as you work. It can be frustrating! 

Check if everything needed is in proximity or on your working bench. Afterward, clean the bike to make it easier to work on.

Cleaning will also make applying some chain lube easier to keep the chain moving freely. Additionally, a clean bike can show some problems on the chain you did not see earlier.

Once the bike is clean and lubricated and all the tools are in order, you can start on the setup.

Setup

Once you have all the tools together, prepare your work area. Get your bike into position by ensuring it is on a stand or a flat workspace like the garage floor. Center the bike so the back wheel can rotate freely off the ground.

Having the bike on a flat surface with a free-moving rear wheel makes it easier to access parts of the bike, such as the axle. This will also make it easy to oil the chain later on.

Afterward, get your tools nearby, and prepare something soft to kneel on. You can then check the chain block alignment, as it will set the chain length when tightening.

Tighten Up

Now that the wheel is off the ground and stable, you can begin the adjustments.

Step 1: Loosen Up the Rear Axle Nut

Use a wrench to loosen the axle nut. It will be 32 mm on most dirt bikes, but you can use a 250 mm crescent wrench instead. Twist the nuts counterclockwise until the axle can move freely. Go slowly while only making a quarter turn each time.

If you use a crescent wrench, be careful not to round the edges of the nut, as the wrench might keep slipping off. See that it is well-adjusted so that it is tight on the nut.

Step 2: Loosen Adjuster Bolts and Locking Nuts

Use a 10mm and 12 mm wrench to loosen the lock nuts on the adjuster bolts against the swingarm. You might have to use a different wrench size if the manufacturer recommends it.

The wrench should be appropriately sized to avoid stripping the bolt or the nut.

Place the 10 mm on the adjuster bolt and the 12 mm on the locking nut. First, crack the locking nut and once it gets loose, go ahead and loosen the adjusting bolt.

You should pull the wrench counterclockwise to loosen the locking nut. Do this on both sides of the swingarm.

Step 3: Adjust The Chain

You can now begin to thread the adjustment bolts to tighten the chain. Threading the bolts out pushes the axle block back and tightens the chain. When pushing the axle block back, only move the adjustment bolt a quarter turn each time.

As you do this, the bike chain should begin to tighten. Ensure that you align the axle block to the adjustment marks on the swingarm. Keep track of the adjustment marks as you move the wheel back.

Adjust the chain till you have the correct tightness on the chain. Aim for three fingers’ worth of tension when placed below the chain slider for the adjustment. The distance between the three fingers should match the distance between the bottom of the chain and the swingarm.

Adjust the left side first to avoid making multiple adjustments afterward. Then move to the right side and keep the adjustments even to keep the axle aligned, so the wheel stays true.

Also, the axle should not be completely tight. It should be movable by the adjuster screws on the chain block.

Step 4: Measure The Chain Slack

Get to the midpoint between the rear axle bolt and the front sprocket. At this point, determine the right amount of slack using a ruler or a chain slack measurement tool. 

Correct chain slack should be around 30 – 40 mm at the end of the chain guide for most bikes. But this might vary depending on the type of dirt bike, so refer to the owner’s manual to see your correct chain slack.

When measuring the chain slack, ensure the axle blocks are against the bolts. You might get a false reading on the chain tension if there is a gap. 

When using a ruler, push the chain to its highest point and put the ruler on the link pin. Then move the chain to the lowest point and find the distance between the upper and lower positions.

Step 5: Tighten The Lock Nut With The Wheel Aligned.

Now that the chain is correctly adjusted, it is time to tighten the locking nut. Use the 12 mm wrench when tightening. Pull the wrench clockwise and do this on both sides of the swingarm.

The wheel has to stay adequately aligned with the axle. Make sure of this by using a chain alignment tool or a ruler. Measure from the back of the swingarm to the axle block.

Determine this measurement on either side and confirm that it is equal.

Step 6: Re-Tighten The Axle Lock

Place a rag between the chain and the sprocket, then spin the wheel back. The rag will jam and cause tension on the chain. This will, in turn, pull the adjuster bolts against the block for solid contact.

After this, tighten the axle nut (turn clockwise) to the correct specs in your owner’s manual. Usually, most dirt bikes should be torqued to 65 – 75 ft-lbs. Then remove the rag and confirm that the chain blocks are correctly aligned and not crooked.

Step 7: Inspect The Chain

After finishing, check that the bolts and nuts have been properly tightened. Also, examine the chain slider to ensure they are not worn out.

Inspect the chain roller to ensure no up-and-down movement. After that, confirm how the links slide under compression and tension.

Additionally, check the sprockets and see that the teeth are still flat and not sharp. In the case of any issues, you may need to do replacements. 

How to Clean a Dirt Bike Chain

Keeping a clean chain helps the bike to run efficiently and quietly. It also prevents rust and increases its longevity.

It is always best to clean the chain at least once a month. However, this depends on the type of terrain you ride on. 

To clean your motorcycle chain:

• • Set your bike up and ensure the back wheel is not touching the ground.

• • Get your cleaner or degreaser and apply it on the chain, working your way around it.

• • Once you soak the chain in the cleaner, brush using the cleaning brush to get the stuck dirt out.

• • Re-spray the chain with the cleaner to remove or dissolve any dirt that does not come out.

After cleaning it, let it dry out completely. You can use a cloth to remove any cleaner that may still be on the chain.

Please take your time with the drying process. Let the chain be as dry as possible since the drier it is, the better the oil will stick. Then, apply your lube or oil to the chain when the drying is complete.

Keep the chain oiled frequently to ensure the smooth running of your bike. You can do this after covering every 300 – 500 miles.

Final Thoughts

Tightening a chain on a dirt bike is an essential skill for any rider. Maintaining the correct chain tension is critical to make the chain last longer. It also prevents the loose chain from skipping over teeth in the sprockets or falling off, which could be dangerous when riding. When tightening a loose chain, confirm with the manufacturer’s manual. You will get more insight into the right amount of drive-chain slack.

Pro Tip: After tightening the chain, consider lubricating it using lube designed for motorcycles. While you can go for other choices, such as engine oil, they are not specially made to resist dust or water. They can leave the chain vulnerable to corrosion or other elements when riding on watery or dusty trails.