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How to Tighten a Bike Chain: Everything You Need to Know

Conrad Kühn

3,2,1 go! You’re off to a great start, you feel the tension and you’re gaining momentum and suddenly the tension is no more, and you feel your legs move faster.

You look down and the chain has come off, and just then your friends zoom past you while you can’t even move an inch.

I’ve gone through this scenario so many times, I’ve lost count.

The natural response to such a situation is to take the bike to the closest bike shop. You’d have to spend a couple of dollars to get it back up and running but going to the bike shop to get your bike serviced every time the chain keeps falling off can be a nuisance. 

That is why I decided to write this guide on how to tighten a bike chain at home in a few easy steps.

cyclist riding fast
Follow this super easy guide and you can be like this guy, 
cyclist falling off the bike
AND not this guy.

What is a Bike Chain?

If you are new to the world of cycling, a bicycle chain is one of the more important components of a bike. Without a chain, a bike has no purpose.

It is responsible for the power transfer between your strokes and the drive wheel which in turn makes the wheels go round and round. (Yes, Just like the wheels of the bus).

Tension in a bike chain is crucial because a loose bike chain causes loss of power and efficiency.

Why Does My Bike Chain Become Loose?

Even a well-maintained bike will have the chains loosened from time to time. This doesn’t mean it’s time to switch bikes, it can happen for several reasons,

• A new chain on an old bike – A new chain might not fit well with worn-out chain bands or cogs. Don’t worry if this occurs, just tighten the chain using this guide and give it a little time to properly fit in.

• Loose Bottom Bracket – Just a small tightening would do.

• On Multi-gear bikes, it can be a loose derailleur.

• Loose nuts on rear end axle – This causes the steering wheel to slide forward, reducing the distance in the middle of your pedals and wheel. This causes a loose string making the chain fall off.

close up of a bike chain

Is Regular Maintenance Required for a Bike Chain?

To maintain the efficiency of a bike chain, regular maintenance and lubrication is a must! 

If not lubricated regularly the chain is more prone to rust and will wear off, causing it to loosen frequently. 

The chain should first be cleaned of any dirt on the surface before lubricating. Lubricating a dirty chain just makes the situation worse.

How Tight Should a Bike Chain Be?

It should be tight enough to move about half an inch in either direction. If you follow this guide to tighten your loose chain and it still slacks, the chain might have expanded over time.

When Should I Pick Replacing Over Tightening?

This answer depends on how long you’ve been using the chain. If it’s quite old, the frequency of your chain loosening and falling off increases. You can still tighten it but you’d have to do it more often than you would like to.

We’re going to look into two types of bikes in this guide.

1. Single Speed Bikes

2. Multi-Gear Bikes (with Derailleurs) 


• Socket Wrench
• Bike Stand( Not Compulsory)
• Rag
• Lubricant
• Gloves
• Socket Wrench Adapter

How to Tighten Up a Loose-Fitting Chain on a Single Speed Bike

STEP 1: Set the bike in the correct position 

A professional mechanic can handle this while the bike is standing right side up, but if you are reading this guide chances are you’re not one.

Flip the bike so that the saddle and handlebars are facing down. You should be facing the wheels, giving you easy access to the chain and the rear end of the bike.

A bike stand is ideal for this step but isn’t necessary. A bike stand prevents the saddle and handlebars from scratches and can be set up to hold the bike in a comfortable height for you to work on.

To protect the saddle and handlebar from scratches, you should lay out a later of cardboard, newspapers, or even a soft piece of cloth.

STEP 2: Release the rear axle

The socket wrench comes to play in this step.

To gain access to the chain and adjust it, you need to remove the nuts that connect the tire to the bike.

Using the socket wrench loosen the nuts by turning it in an anti-clockwise motion.

STEP 3: Drag the Rear Tire Back

With the tire still centered in the wishbone, slowly pull tire towards the back. The tension of the chain is increased by performing this step in a controlled manner. 

You do not have to yank it back with all your power. A quick movement might cause the chain to crack but a slight pull will create enough tension. How much tension is enough? 

Step 4: Get the right amount of tension

As mentioned before, ideally the chain should be able to move around by half an inch in either direction.

Pulling the tire as discussed in the step above creates the tension. 

If the chain moves more than about half an inch there is still some slack and the chain isn’t tight enough, pull the back tire a bit more and feel the tension increase.

If you’ve pulled the tire more than the optimum amount, the chain will be too tight, and the pedals won’t turn.

This step is crucial, and you need to get it right.

Step 5: Put Back the Rear Tire

When adjusting the tension, the tire should always be kept centered to the wishbone, which makes it easy to tighten it after the right tension is attained.

Once the right tension is established, replace each axle nut one at a time using the socket wrench and make sure the tire isn’t in contact with the frame or chain.

Step 6: Test 

Ideally, the chain should move about half an inch in either direction. Test this by moving the chain in either direction. See if the rear tire has been fitted properly by giving it a spin and check if it touches the chain or bike frame whilst in motion.

Single Speed Bike

How to Tighten a Loose-Fitting Chain on a Multi-Gear Bike

STEP 1: Set the bike in the right position

This process is similar to that of a single gear bike. To access the rear tire and derailleur, the bike needs to be flipped upside down.

If you have a stand, hook it up in a comfortable position. If you don’t, lay out a cardboard and rest the bike on its saddle and handlebar.

STEP 2: Look for the Derailleur screw

On most bikes, there is a bolt with the letter B printed on it behind the rear derailleur. To increase tension, turn this bolt in a clockwise motion.

STEP 3: Gain access to the rear tire

To access the rear tire, you need to remove the brakes from the cable. Lift the brake lever and then raising it will help you gain access to the back tire.

STEP 4: Tweak the back tire

To increase the stress on the chain, slide the rear axle backward toward the tail dropouts slowly, sudden movements can make the chain too tight.

With every small correction lower the brake lever and test out to see if you have enough pressure, if not lift and continue to make small adjustments until you feel like you have enough tension. 

Ideally, the tension should move about half an inch in either direction.

STEP 5: Restore order

Once ideal tension is reached, its time to put everything back in place. 

Make sure the brake lever is down and the brake cable is connected. You do not want to ride around on a bike without brakes.

Spin the wheel to make sure that it is fitted properly. See that it doesn’t come in contact with the frame or chain whilst spinning.

With that, we have come to the end of our guide. Follow these simple steps to get your bike chain tightened. It may seem hard at first, but it’s not. Practice makes perfect and after a couple of times, you will get the hang of it.

The next time your bike chain comes off or is loosened, you don’t have to replace the chain or visit your nearest bike shop. Make sure you bookmark our guide and use it for a quick fix.

Wait… what are the gloves and rag used for?

Good question, while performing the above steps, make sure you have gloves on to protect your fingers from cuts and use the rag to wipe away dirt and lube.

Conrad Kühn
About the Author
Cycling Enthusiast / Mechanical Engineer | Hailing from Germany, where the first bike was invented is no coincidence. The cycling bug hit Conrad when he was really young, and he has been sick for quite some time now. Germany is a leading cycling nation. His first cycling experience began with him commuting to school with his friends. Racing to school was the best feeling ever. As Conrad grew up so did his passion for cycling. He used to race in local competitions but never made it to the professional level because of his other love: Engineering. As a mechanical engineer by profession, Conrad loves to understand the mechanisms behind machines and how they work. This intensified his passion for bicycles. Engineer by day and blogger by night, Conrad wants to share his knowledge with the global cycling community.
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