How to Tighten a Bike Chain

A bike chain is an important component of any bicycle. When you pedal, it will transfer your power to the wheels allowing you to move forward. When the chain is loose, the rate of power transfer drops, and you will not be able to propel the bike forward.

If you use your bike regularly you will gradually experience a loose or detached chain. This doesn’t mean that there’s anything wrong with the bike, you just need to quickly learn how to tighten the bike chain with the right set of tools.

To help you with that, we will take you through a step-by-step process on how to tighten a bike chain.

How to Tighten a Bike Chain On a Single Gear Bike

This is a type of bike that has only one gear; instead of a freewheel mechanism in the rear wheel, it has a cog. When you cycle, the cog turns and then the wheels turn.

Step 1: Flip the Bike

Flip your bike wherein the wheels should be in the air or use a bike stand.

You should be in a comfortable zone to be able to tighten the chain perfectly and be careful not to get injured by the sprocket teeth.

If you don’t have a bike stand you should lay out a soft surface (like a piece of a cardboard box or a layer of newspapers) so that you don’t scratch the saddle. 

Step 2: Loosen the Rear Tire

Carefully loosen the axle nuts by using a socket wrench and torque wrench.

These nuts hold the rear tire and will help you adjust the tension in your chain. 

Step 3: Pull Rear Tire

Now pull back the rear wheel towards the back, which will increase the tension of the bike’s chain. 

Remember not to pull the tire so much or it can break the chain on the sprocket. So, do this step slowly. 

Step 4: Recognize the tension

Identify the right chain tension by moving it half an inch around in both directions. If it moves a bit more then push back it further. 

Step 5: Tighten Rear Wheel

After fixing the chain tension, tighten the axle nuts carefully. 

Ensure that the rear wheel is fitted on the cycle frame and always check the position of the rear tire while tightening the nuts.

Step 6: Check the Chain Slack

If you have done all the steps successfully then it’s time to recheck your work. 

Does the chain move about half an inch in either direction? If yes, then you have to tighten the bike chain very well, if not, then you have to repeat all steps once again. 

How to Tighten a Bike Chain On a Multi-Gear Bike

On a multi gear bike, multi speed bike or a dirt bike, you have to follow an imperceptibly different method to tighten the bike chain.

It is quite natural for the mountain bike chain to get grabbed in the foot while you are cycling when a chain is loose in a bike with a derailleur. So, it’s better to walk your bike in a safe place if you have noticed the loosened chain. 

Step 1: Flip the Bike

Flip your bike wherein the wheels should be in the air or use a bike stand so that the tire and derailleur are within your reach.

If you don’t have a bike stand you can find a soft surface that doesn’t scratch the saddle and handlebars.

Step 2: Locate the Derailleur Screw

There is a screw at the back of the derailleur on multi-gear bikes.

On most bikes, you’ll find the letter B, and next to it will be the screw.

To increase the tension on the bike chain you’ll need to turn this screw clockwise in a tightening motion.

Step 3: Access and Adjust

Access and adjust the rear tire by disconnecting the brakes from the cable, so lift the brake lever and then raise it so that you have access to the rear tire.

Step 4: Adjust the Rear Tire

To increase tension on the chain of a derailleur, you have to slide the wheel axle toward the rear dropouts making only small adjustments as you go along, but you don’t want the chain to become too tight.

For each adjustment, you have to lower the brake lever and check if you have enough chain tension. If not, lift the lever and continue to make adjustments until you are comfortable with the result.

Step 5: Assemble and Check

Once you feel that you have enough chain tension you should put everything back together just as it was and make sure that the derailleur screw is properly fitted and tight enough.

Check that the tire is spinning properly and doesn’t come in contact with the bike frame or the chain itself.

If you aren’t happy with the tension, repeat the steps again.

How to Tighten a Bike Chain On a BMX Bike

If you are an owner of the BMX bike, you will need to follow the steps below properly.

Step 1: Check the Chain’s Tightness

Tightening a BMX chain is easier than the geared bike chain.

What you need to do is pinch the chain together, if you can remove it from the chairing then it’s loose. This is because you cannot move a correctly installed chain when pinching together. 

If your chain is tight enough to ride and it is not hitting the frame of the rear triangle then there is no big issue. In the other scene, if the chain is loosened do the steps I have shared below. 

Step 3: Chain Size

Make sure that your bike chain has the right amount of chain links. Due to the short rear horizontal dropout, it is particularly significant for BMX bikes and single speed bikes. 

If the BMX chain has an accurate amount of links, it can fit perfectly in your bike. 

You can measure the correct length of a chain by pushing the wheel as far forward as possible in the dropouts. Then wrap the chain in both of your chainrings.

If the chain overlaps itself by one link then you need to remove the link to give a perfect length of the chain.

Step 4: Set up

This is a confusing step, so concentrate on setting the bike up nicely and comfortably.

Firstly, find an open and bright area to do the work efficiently. Now, flip the bike so that the tires could be in the air and it rests on the handlebars. In this way, you can do this job quickly. 

Step 5: Tools for Unlinking the Chain

Have one spanner for each side of the wheel so you can tighten the chain and make sure the spanner fits your wheel.

Know that a bike hub is available in both male and female variations. The male one goes through the hub and the dropouts and has an axle. And you need to tighten it with a nut and a spanner. 

On the other hand, the female one stops at the bushes and can be threaded internally. Here, a bolt goes into the axle and is normally tightened with an Allen key. 

Normally, female axles are more powerful than the male one because they don’t have an outer piece of the threaded element. 

A downside of the female axle is that it can’t be used with pegs. For this, they are much less customary for BMX bikes.

Step 6: Loosen Wheel

Now loosen the wheel to the point where you can move either side freely.

If you haven’t any problem removing the wheel’s nuts then loosen the wheel.

Step 7: Attach the Wheel

It’s time to use your chain tensioner.

Most of the time, tension is placed in the rear triangle ahead of the dropouts. Usually, tensioners are not included in the bike frame as they are added to the axles before the nut.

Try to keep your chain on the bike and tighten each side equally. This will help you understand when to stop tightening.

Without a chain tensioner, you have to keep your wheel farther away and align it centrally while tightening the nuts. 

You can use a large metal bar or spanner to push among the bottom bracket area of the frame and the wheel. It will then work like a lever and push the wheel as far as back it goes. Besides that, it can be tilted to either side to align the tire centrally.

How to Tighten a Bike Chain On a fixie Bike

On the surface, fixed gear bikes (fixie) and single speed bicycles are very similar. They both have a single front chainring and rear cog meaning they essentially only have one gear.

Single speed bikes are fitted with a freewheel, whereas fixed gear bikes are not. On a fixie, the rear cog is joined with the rear hub, so when the wheel turns, the cog will turn too.

To tighten a fixie bike chain, follow the steps below.

Step 1: Flip the Bike

Flip your bike wherein the wheels should be in the air or use a bike stand.

You should be in a comfortable zone to be able to tighten the bicycle chain perfectly. 

If you don’t have a bike stand you should lay out a soft surface (like a piece of a cardboard box or a layer of newspapers) so that you don’t scratch the saddle. 

Step 2: Loosen the Rear Axle

You need to remove the nuts that hold the tire to the bike, to be able to perform chain adjustment.

For this, use a socket wrench and carefully turn the nuts in an anti-clockwise motion until they come loose.

Step 3: Pull the Rear Tire

This is where you will increase the tension in the bicycle chain. Carefully pull back on the rear tire until you get the desired cable tension.

This process should be done very slowly, as any quick movements can snap the chain. As you pull back, check the tension and keep going until you have the desired tightness. You should be able to move the chain both ways at least half an inch.

Make sure that the tire remains centered in the wishbone so that tightening it back is easy.

Step 4: Right Chain Tension

The chain should be able to move half an inch in either direction, but I would like to talk about it a little more. As you pull the tire back the chain tension will change, you can feel this as you work.

If it moves too far in either direction it means it isn’t tight enough and should be pushed a bit more on the tire.

If it’s too tight you will not be able to turn the pedals, so it’s important to make sure that you get this step just right.

Step 5: Tighten the Rear Tire

If you’re happy with the chain tension it’s time to lift the rear tire back into place and replace the axle nut. One at a time, replace each and use the socket wrench to make sure that they are all tight enough.

The tire must be properly fitted back onto the frame. When it’s securely in place it shouldn’t touch the bike frame or the chain.

Step 6: Check your chain

Test the chain by moving it a little in both directions; it should move with ease half an inch both ways. 

Spin the tire to make sure that it’s moving properly and doesn’t come in contact with the chain or the frame whilst in motion, if it does it means you’ve fitted it back wrong and you need to repeat the process.

Remember to lube your chain If you use your bike regularly, you should lubricate your bike chain every month or every 150 to 200 miles or 240 to 320 kilometers.

Frequently Asked Question

How do you know if the bike chain is too loose?

To find out whether your bike has a loose chain, you have to take a look at it from the side with your eyes being level with the chain. A loose bike chain will sag close to or below the chainstays as the chain hangs between the rear cogs and chainring. The chain might skip as you pedal, or even drop off the gears.
On derailleur equipped drivetrains, the drivetrain might shift poorly as well.

When should I change my bike chain?

A general rule of changing your bike chain is after riding every 2,000 miles and when you notice chain wear.
Besides that, you can measure your bike chain with a ruler to determine when to change it.
Begin from one link pin and measure all 12 complete links. You may need to put some tension to get the exact measurement. 

You will measure 12 inches with 12 complete links in a new chain. If you find less than 1/16 inch between the distance of the center of the link then it is okay. You need to change the chain if the measurement is more, by using a chain tool.

Conclusion

Keep in mind that the process for tightening a bike chain on a single-gear bike is different from that of a multi-gear bike.

Different types of bikes are built differently and the process may change slightly. Thus, If you aren’t sure what to do, refer to the manufacturer’s guidebook or get directly in touch with them so that they can send you instructions for your specific type of bike.

Furthermore, you can have the chain tightened at a reliable bike shop that has experience with your type of bike.

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By Paul P.

Paul Panha is an avid cyclist and sports performance enthusiast. Regularly on the road testing (and buying) new bikes. Paul is a co-owner of GetBike.fit and is the head resident author here.