Generally, you wouldn’t want your bike chain to be too loose, as it’ll keep on slipping off. You also wouldn’t want it to be too tight as it’ll wear down the chainring or sprocket. But how tight should a bike chain be?
A bike chain should move by about ½ inch (0.5 inches), either up or down. If it moves more than that, then it’s too loose, and if it doesn’t move at all, then it’s too tight.
Overall, there are a few risks of using either a too tight or a too loose bike chain, as I’ll explain. So, your goal should be to keep the chain tension at 0.5 inches.
I’ll show you how to tighten your bike chain and observe the correct chain tension. I’ll also answer some frequently asked questions about the bike chain tension.
But before that, let’s first explain the risks of having the wrong chain tension.
The Risks Of The Chain Being Too Tight Or Too Loose
As I hinted earlier, the bike chain should come with a 0.5-inch tension. Regardless of the bike type, you should be able to move the chain by ½ inch in either direction.
What If The Chain Can Stretch More Than 0.5 Inches?
If so, then it means that the chain is too long or simply loose. The danger of a loose or long-chain is that it makes it hard for the derailleur to pick up.
Plus, the chain slips off when you engage it. So, you have to worry about inconsistent shifting and the reality of not being able to shift at all.
Note, however, that bike chains do stretch when they wear down. If that’s the case, then you shouldn’t struggle to tighten such a chain. What you should do instead is replace it.
But before you can rule that it’s a chain stretch, confirm first with a chain wear tool like the Park Tool CC-4 Chain Checker.
This chain checker shows the chain wear percentage. Overall, you can use it on any ½-inch 5-12-speed bike chain.
What If The Chain Is Too Tight?
You don’t just have to worry about a loose chain but also an extra tight one. If your bike chain cannot move by 0.5 inches, then it’s short (or you can call it too tight).
The problem with such a bike chain is that it can quickly wear down the chainring and sprocket, resulting in damage. The chain may put extra pressure on the sprockets, causing them to wrap.
Also, shifting becomes challenging when the chain is too tight. You may not even manage to shift into the biggest cog, which means you’ll have a hard time cycling.
Note, however, that you don’t need a chain checker here to determine if your chain is too tight. What you should do, nonetheless, is to try and move the chain to see if it can move by a ½ inch.
If it doesn’t, then you’ll need to make it longer by adding a few chain links. In such a case, you’ll need the right tools, which include master link pliers or chain tools.
You can check out the Oumers Bike Chain Repair Tool Kit, which you can use for the job. It has bike link pliers, six pairs of missing links, among other supplies you need to lengthen your bike chain.
How To Tighten A Chain On A Bike
Let’s look at how you can tighten a single-speed (one-gear) bike and a multi-geared option.
But before we can look at the guides, here are the tools that you need for bike chain tightening:
- Socket wrench
- Hex/Allen keys
- Chain lubricant
- Bike repair stand )optional)
How To Tighten A Single Speed Bike’s Chain
Here are the steps to follow to adjust the chain tension of a single-speed:
Step 1 – Bike Positioning
You have the option of flipping your bike upside down to work on it or putting it on a bike stand. A repair stand like the Bikehand Tripod Bike Repair Stand (View on Amazon) holds up to 55 pounds at any angle. Thus, it’s the best choice for the heaviest bikes.
Step 2 – Rear Axle Release
Put on some gloves and start removing the nuts that hold the rear wheel. You’ll need a wrench for this job that you need to turn anticlockwise.
Step 3 – Rear Tire Pull Back
Now that the rear wheel is loose, you should pull it back to give the chain the correct tension. While at it, do it gently to avoid snapping the bike chain.
Step 4 – Chain Tension Adjustment
Here, you’ve to continue pulling back the rear tire until you achieve proper chain tension, which should be 0.5 inches. Stop pulling when you can move the chain by 0.5 inches.
Step 5 – Rear Tire Restoration
Once you are okay with your chain tension, lift the back wheel and put it back into its place before tightening the axle nuts.
Step 6 – Grease Up and Test
Lastly, apply some grease to your bike chain, something you can do with the WD-40 Specialist Bike Chain Lube. The lube prevents both corrosion and friction in all weather conditions.
Then use a rag to wipe off the excess lubricant before counter-testing the chain tension.
How To Tighten A Multi-Geared Bike’s Chain
Are you looking to tighten mountain bike chain? Here are the steps for adjusting the chain tension of an MTB or any other multi-geared bike:
Step 1 – Bike Positioning
If you are comfortable working with your bike upside down, flip it so. But if you aren’t, then find a bike repair stand and mount your bike there.
Step 2 – Derailleur Screw Adjustment
Identify the screw marked B (or the derailleur screw) that you find on the derailleur. Once you find it, use an Allen key to turn it clockwise.
If you have no Allen key, consider the EKLIND 53910 Allen Wrench Set, which has a set of 10 keys.
The keys have longer shafts to offer you more leverage, and feature cushion grip handles to allow you to adjust the screws more comfortably.
Overall, this step allows you to increase the chain tension.
Step 3 – Rear Tire Access
First, lift your brake lever and disconnect the brake cable to access the back tire fully.
Step 4 – Increase Chain Tension
Gently slide your wheel axle to the direction of the dropouts to increase the chain tension. Do it gently until you get the correct tension, which should be 0.5 inches.
Step 5 – Restoration and Lubrication
Lastly, put things back as they were before lubricating the chain. That marks a successful multi-geared bike chain tightening process.
However, don’t forget to put on gloves when working and wipe off the excess lubricant using a rag.
1. Can A Bike Chain Be Too Tight?
A bike chain can be too tight if the chain tension is more than 0.5 inches. In such a case, the chain becomes shorter. So, you cannot move it upwards or downwards.
Remember, the acceptable chain tension limit is 0.5 inches. Anything more will wear down the drivetrain components.
2. What Happens If Your Bike Chain Is Too Loose?
Since the chain delivers leg power to the drivetrain, the rate of leg power transfers drops when the chain is loose. As a result, it becomes harder to shift or propel the bike.
The other thing is that the chain will start slipping off, and you may not be able to cycle at all.
3. How Tight Should A BMX Chain Be?
The BMX chain tension should be a half-inch. What this means is that the chain should only move by a half-inch either upwards or downwards.
If it’s too tight, then you could likely wear down the drivetrain and complicate the shifting. And if it’s too loose, then the chain will start slipping off.
4. Is My Chain Too Slack?
Your bike chain should be long enough to allow you to shift smoothly but not too long to slip off the chainring. Overall, you can tell if your chain is a little stretched using a chain wear tool.
5. How Do I Know If My Chain Is Too Short?
If your bike chain is too short, the shifting becomes much more complex as the derailleur stretches. You may even find it impossible to shift into the rear cog.
6. How Do You Adjust The Chain Tension On A Mountain Bike?
First, identify the B-screw (or derailleur screw) and then adjust it depending on the chain tension you want.
Do it clockwise to increase the chain tension or make the chain tighter. And if you want to loosen the chain (or decrease the chain tension), turn the B-screw anticlockwise.
Closing Thought: How Tight Should A Bike Chain Be?
So, how tight should a bike chain be? As discussed, a bike chain shouldn’t be too tight or too loose. Instead, its tension should be about 0.5 inches.
That’s the only chain tension that can guarantee the best performance from your bike chain.