close up of a man tightening his bike chain in workshop

Bike Chain Keeps Falling Off: How to Tighten a Bike Chain in 6 Easy Steps?

Is your bike chain too lose that the bike chain keeps falling off as you ride? With your bike chain slipping and coming off over and over again, you must be thinking that there is something wrong with your bike and you need to take it to the mechanic. But no, probably there is nothing wrong with your bike, except its chain needs a little tightening.

Do you not know how to fix a bike chain? You must be pretty mad at your bike for disappointing you and maybe at yourself for not knowing how to tighten a bike chain? Well, fret not. Tightening a bike chain is no brainer—if you have right tools by the end of this article you will know how to tighten a bike chain like a pro.

Bike Chain Slipping

Loose bike chain is annoying—at best it can ruin your ride and at worst it could pose a safety hazard. Imagine your mountain bike chain comes off as you are enjoying a thrilling downhill ride or maybe your road bike chain fall of as you are in the middle of the road. Scary?!

Read: How to Put a Bike Chain Back On in 4 Easy Steps?

You are not alone—every person who bikes regularly or peddles once in a blue moon, eventually has to experience a loose or detached bike chain.

Therefore, you are advised never to ride a bike with chain so loose that it keeps falling off while you ride.

Before you hop on your bike for a ride, you should make sure that not only its brakes but also its chain is tightened perfectly.

Before we move on to learning how to fix a bike chain or how to tighten a bike chain. We should first know why bike chain keep loosening up.

So let’s get to it.

Why Does My Bike Chain Keeps Loosening Up?

Depending on the bike gearing system and mechanics, there could be different reasons behind your sagging bike chain.

1. Single-Gear System

If what you have is a single-gear or fixed-gear bike, most probably the reason behind you lose bike chain are the nuts that are holding the tire to the back. Actually, these nuts often loosen up, making the tire to slide forward—resulting in the loosening of the tension in the wheel as the distance between the wheel and pedals has shortened.

2. Multi-gear System

In case you have a multi-gear bike, most probably the culprit behind your bike chain slipping is derailleur. Derailleurs are used on multi-gear or multi-speed bikes. They help you to change gears on your bike by pushing the bike chain sideways so that it can move onto next sprockets.

The derailleur is also responsible for maintain a perfect tension in the spring but it does not immunize multi-gear bikes from sagging chains. Derailleurs are fragile so if they hit something they may get bent leading to bike chain slipping and sagging chain.

3. Wear and Tear

It is also a possibility that your bike chain has run its course. Almost every bike needs at least one chain replacement in their lifetime because with age the chain not only stretches but also wear down. So, if you think your bike chain is too old to be tightened anymore, you should invest in a new bike chain, instead of trying to tighten it as it won’t work.

4. New Bike Chain

Yes, you read that right. A brand-new bike chain can also be loose. This mostly happens if the length of the new bike chain that you got for your bike is longer than the required. So obviously, if the chain is long, it will be saggy and will come off as you ride the bike. So you will have to shorten it a little so that it is sitting perfectly with perfect chain tension.

Now that we have learned what causes a loose chain, let’s discuss what tools are you going to need to tighten a bike chain.

Read: Changing Bike Pedals: How to Take Pedals off a Bike? 3 Easy Ways!

What Tools Do I Need to Tighten a Bike Chain?

For tightening the bike chain that keeps falling off, you’ll be needing the following tools:

  • Socket wrench
  • Bike lubricants
  • Pair of gloves (if you don’t want to get your hands dirty)
  • A rag (to clean unwanted lubes)
  • A bike stand (to make bike maintenance convenient)

Ready to get your hands dirty? Let’s have at it.

If you do not like to get your hands dirty, wear a pair of gloves and maybe use a rag to wipe away any unnecessary lube.

How to Tighten a Bike Chain on Single-Geared Bike?

If you are having a single-geared or single-speed bike then this method is for you. If you have a multi-gear bike, you should move on to the next section about “how to tighten a bike chain on multi-gear bike?”

Before getting to the ‘how-to’ part, you should make sure that you have necessary tools.

Here is how to tighten a bike chain on single-geared bike in 6 easy steps:

1. Flip Your Bike

If you are experienced mechanic, you will be bale to tighten bike chain with the bike standing right-side up—you won’t have to flip the bike. However, if you are a novice mechanic, it is better to flip the bike with tires in the air. If you have a bike stand, you can put the saddle on the stand with wheels in the air. If you do not have a stand, you can simply put your bike upside down.

Flip your bike on a soft surface to avoid unwanted scratches on the saddle. You can simply put some newspaper or cardboard on the surface.

2. Loosen the Rear Axle

Using a socket wrench, you will have to loosen the rear axle that is responsible for holding the rear wheel in place. You will have to move the nuts in the clockwise direction to slacken off the rear wheel.

Righty tighty, lefty loosy. Turn the nuts in anticlockwise direction to loosen them and clockwise to tighten them.

3. Slide Rear Wheel Backwards

Now that you have loosen up the rear axle, you will be able to move the wheel forward or backward. In order to tighten the bike chain, you should pull the rear wheel towards back, which will tighten the bike chain.

Be careful while pulling back the bike chain—pull it slowly while ascertaining the tension in the bike chain. If you pull rear wheel too much it can break the bike chain. You

4. Correct Bike Chain Tension

You don’t want to tighten bike chain so much that there is a risk of its breaking down. You want just the right amount of tension so that there is no more bike chain slipping. A perfectly adjusted bike chain will be able to move around half an inch in either direction.

If the bike chain is moving a little farther than a half inch, you will have to pull the wheel further backwards, and if the bike chain is moving quite less than half an inch, you will have to slightly slide it forward to reduce tension.

5. Tighten the Rear Axle

Now that you have adjusted the bike chain tension, you need to fix the rear tire back into place, making sure that it does not slide backward or forward as you are tightening the axle. While tightening the axle, you will have to ensure that the wheel is in perfectly positioned—it is making no contact with the bike chain or bike frame.

6. Test it

Before you hop on your bike for a quick spin around the block, you should make sure that everything is adjusted perfectly: you can move bike chain half inch in either direction; on spinning, tire is neither making contact with the bike chain and nor with the bike frame.

If anything seems wrong, you would have to repeat the process. But if everything is working perfectly, you should pat yourself on the back and take it out for a test ride.

Now that we have learned what causes a loose chain, let’s discuss how to tighten a bike chain.

How to Tighten a Bike Chain on a Multi-Gear Bike?

While tightening a bike chain on a single-gear bike is not much of a hassle, same cannot be said about a loose chain with a derailleur.

No doubt tightening a bike chain with a derailleur is a bit technical, it is no reason for ignoring a lose chain. In fact, a lose bike with a derailleur is way more dangerous than a lose bike without a derailleur. Lose bike on a multi-gear bike can entangle your foot an do some real damage to your foot. So as soon as you sense a sagging bike chain, you should stop riding and get it fixed from a nearby bike shop or maybe fix it yourself.

If you are thinking of fixing the bike chain yourself, here is how to tighten a bike chain on a multi-gear bike:

1. Flip the Bike

To have a go at fixing the bike chain with a derailleur, you will have to put it on a bike stand or maybe flip it so that bike is resting on the saddle and handlebars. This way you will have easy access to the rear tire.

2. Locate the Derailleur Screw

Derailleur screw is quite easy to spot as there is a letter B printed right next to it. On most bikes, it is positioned at the back of the derailleur. By turning the screw clockwise, you can increase tension in the bike chain.

3. Disconnecting Bike Brakes

To get access to the rear wheel, you will have to first detach the bike brakes by simply lifting the release lever and disconnecting the bike brake cable.

4. Adjusting the Rear Tire

Now life the quick release on your tire and slide it a little backward in the rear dropouts to tighten the bike chain. Lower the quick release when you think there is just right tension in the bike chain.

Slowly slide the wheel back into the rear drop outs considering the bike chain tension—you do not want the bike chain so tight that paddling becomes impossible or your bike chain breaks down.

5. Repeating Step 4 Until You Get the Perfect Bike Chain Tension

If the bike chain is perfectly tightened—you can move it a half inch in either direction—you can skip this step. However, if the bike chain tension is bit too much of too low, you will have to carefully repeat the step 4 until you get the perfect chain tension.

6. Putting Everything Back Together

Now that you have tightened the bike chain, it’s time to put back everything back where it belongs. Connect the bike brakes and make sure that derailleur screw is tight enough.

Double check if the bike brakes and wheel is perfectly placed. Bike brake calipers should not be rubbing on the wheel. Similarly, the tire should not be making contact with bike chain or bike frame.

Now that you have made sure that everything is working perfectly, you can hop on your bike and take it out for a quick ride around the corner.

After having learned about how to tighten a bike chain, maybe you want to take a look at how to fix bike brakes.