Essentially, a chain’s purpose is to transfer pedaling power to the bike’s wheels to enable you to go forward. So, if the chain is loose, you won’t be able to propel the bike. Below is a summary of how to tighten a chain on a bike:
Position your bike upside down or on a bike stand. Then loosen the rear axle and pull back the rear tire to increase the chain tension if it’s a single-speed bike chain. However, if it’s a multi-geared bike chain, turn the derailleur screw clockwise and adjust the rear wheel. Lastly, continue adjusting the chain tension to about ½ inch before putting everything back.
We are going to look at how you tighten a single-speed bike chain and a multi-geared bike chain. We’ll also look at how you can tighten the chain of a Fixie and a BMX.
How To Tighten A Chain On A Bike: Single-Speed vs. Multi-Geared Bike
Before we can look at the chain tightening process, let’s look at the tools you’ll need.
Since you’ll be coming into contact with grease, you need gloves to protect your hands.
- Socket Wrench and Socket Wrench Adapter
A socket wrench helps you to fasten the bolts when tightening your bike chain. On the other hand, a socket wrench adapter allows you to reach a bike’s peg to screw and unscrew the bolt quickly.
In case you want a socket wrench and socket wrench adapter combo, get the Universal Socket Wrench.
- Hex/Allen Keys
Allen keys are for adjusting the chain tension. In their absence, you can use a screwdriver.
- Bike Stand (optional)
You’ll work much better with a bike repair stand than without it. It holds your bike firmly when fixing the chain, and you can also use it to do any bike repair.
It’s best if you have a rag with you for wiping off excess grease from the chain. It’ll also help you get rid of dirt and dust.
- Chain Lube
After tightening the chain, you’ll need to grease it a little to prevent friction and corrosion. One good choice is the Finish Line 1-Step Bicycle Chain Cleaner & Chain Lubricant.
How To Tighten A Chain On A Single-Speed Bike
Once you have the right bike chain adjustment tools, follow these steps to tighten your single-speed bike chain:
Step 1 – Position the Bike Correctly
You can turn the bike upside down and allow it to rest on its seat and handles. But if you have a bike stand, you can mount it there.
Step 2 – Loosen Up the Bike’s Rear Axle
The rear axle refers to the shaft which holds the tire. So, you have to release it by turning the socket counterclockwise.
Step 3 – Pull Back the Rear Tire
Now, gently pull back the tire to increase the chain’s tension. Avoid doing it fast, as that may crack the chain.
Step 4 – Adjust the Chain Tension to ½ Inch
The chain should move up and down by a half-inch. So, if it stretches more than a half-inch, you have to continue pulling back the tire until you achieve the correct tension.
Step 5 – Refit the Rear Wheel
Now, put back your rear wheel and tighten it.
That’s it! You just tightened the chain of your single-speed bike. You can test the chain to ensure it’s not loose.
How To Tighten A Chain On A Multi-Geared Bike (How To Tighten A Bike Chain With A Derailleur)
The process of tightening a multi-geared bike chain is slightly different from that of a single-speed chain because of the derailleur.
Here are the steps to follow:
Step 1 – Position the Bike Correctly
You can flip your geared bike upside down to allow it to rest on its saddle and handlebar. But if you have a bike stand, use it.
Step 2 – Turn the Derailleur Screw
Locate the derailleur screw (marked B) and rotate it clockwise using an Allen key to increase the chain’s tension.
Step 3 – Access the Back Wheel
Detach the brakes, and then lift your brake lever to access the rear tire.
Step 4 – Adjust the Back Wheel
Now, slide back the wheel axle, just behind the rear dropouts, to improve the chain tension. Continue adjusting the back wheel until you get the correct chain tension (that’s about ½ inch).
Step 5 – Put Things Back
Lastly, return the wheel, brakes, and brake lever as everything was before.
How To Tighten A Chain On A Fixed-Gear (Fixie) Bike
There isn’t much difference between a Fixie and a single-speed bike when tightening a loose bike chain. So, follow the steps I’ve shared on tightening a single-speed bike chain when it comes to a Fixie.
How To Tighten A Chain On A BMX
Overall, tightening the chain of a BMX is much easier than that of a geared bike. You can follow these steps to do it like a real pro.
Step 1 – Position Your BMX Correctly
Find an open space and turn your BMX upside down to allow it to rest on its handles and saddle. But if you have a bike stand, you can use it to hold the bike.
Step 2 – Loosen the Rear Wheel
Using a socket wrench, two spanners, or Allen keys, loosen the bike’s back wheel.
Step 3 – Adjust the Chain tension
If your chain has a built-in chain tension, use it to tighten it (the chain) on both sides. If the chain tensioner is not present, use a spanner to keep the wheel far back as you tighten its nut.
Step 4 – Keep the Chain Tight
Here, you only need to continue tightening the chain until you achieve your desired tension. That is until the chain is no longer loose.
How Do I Tighten Bicycle Chain On A Mountain Bike
You have to tighten the chain of a mountain bike like any multi-geared bike. In that case, follow these steps:
- Position your MTB on a bike stand but if you don’t have it, flip the bike upside down and let it rest on its handles and seat.
- Locate the derailleur screw (normally marked B) and then rotate it clockwise using an Allen key to increase the chain tension.
- Disconnect the brake cable and lift the brake lever to access the rear wheel.
- Now slide the thru axel backward and tighten the derailleur screw anticlockwise to improve the chain tension.
- Once you have the correct chain tension, put everything back.
Remember, you can always use a mountain bike chain tensioner like the Quintessentialz Chain Guide Mountain Bike Tensioner to apply the necessary tension on your chain and prevent its slacking.
1. Why Is My Bike Chain Loose?
Even after taking proper care of your bike chain, there’s always the risk of it slacking and slipping off. So, what could cause that?
Well, here are things that can make your bike chain slack:
- Adding a new chain to an old drivetrain – If the drivetrain components, especially the chainring, are worn out, the new chain will likely become loose. To stop that, you’ll need to replace the worn-out drivetrain component.
- Loose rear axle nut – If the nuts on your rear axle are not tight, the chain tension relaxes as the distance between the rear wheel and pedals reduces.
- Derailleur damage – In the case of multi-geared bikes, damage to the derailleur could loosen the chain.
2. How Tight Should A Bike Chain Be?
A bike chain should move by about a half-inch in either direction. If it’s loose than that, then you should tighten it. But if it’s worn out, then it may be wise to replace it.
3. When Should I Replace My Bike Chain?
Generally, you should replace your bike chain when it shows signs of wear. You can identify a worn-out chain using a chain checker.
This chain checker shows you the chain wear percentage, which could be anything between 0% and 1%. The closer the percentage is to 1%, the higher the wear.
The other way to know that it’s time to replace your bike chain is by observing the 2,000-miles rule. The rule dictates that you replace your bike chain after 2000 miles of usage.
Now you know how to tighten a chain on a bike. So, whether you have a single-speed or geared bike, you can use my guide to adjust its chain tension. In the long run, that ensures you have a better cycling experience.