As a bike enthusiast or commuter, you must know the importance of proper chain tension. A well-tensioned chain is crucial to ensure efficient power transfer. Meanwhile, it also reduces wear and tear on your bike’s drivetrain components. However, the question is, “Are chain tensioners necessary” for maintaining optimal chain tension?
Keep on reading to get a comprehensive answer to this question. In this article, we will explore what chain tensioners are, their working mechanism, and several related aspects.
Following our guide, you can convert your bike gear into single-speed seamlessly. So let’s get started with it.
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ToggleWhat is a Chain Tensioner on a Bike?
Before we debate about are chain tensioners necessary, let’s first discuss what is a chain tensioner. It is one of the most critical components of a bike which ensures the chain’s tightness and whether it’s adequately tensioned or not.
Not having a chain tensioner on the bike will increase the chances of accidental slips. It happens because a loose chain can lead to the slipping of the gears. In addition to this, a loose chain can cause excessive friction and drag too, decreasing your bike’s speed.
Purpose of a Chain Tensioner
As discussed earlier, a chain tensioner is used to maintain appropriate tension in the bike’s chain to prevent it from slipping. Besides offering improved safety, this component is also helpful in ensuring the high performance of the bike.
Moreover, with proper chain tension, the power output will also be maximum, especially if you own an e-bike.
Read More: What Size BMX Chain Do I Need for my BMX Bike
Types of Chain Tensioners
Before discussing are chain tensioners necessary, it’s important to know their types. Chain tensioners basically have two primary types, i.e., push-down and push-up. Push-down tensioners are more famous as they are compatible with more bikes and drivetrains.
A push-down chain tensioner pushes the chain downwards from above the cog. Through this, the chain tension declines, and gear shifting becomes easier. However, it may not offer much chain wrap, leading to an unstable riding experience.
Contrarily, the push-up chain tensioner has a mechanism that ensures the chain wraps completely over the rear cog. This tightens it so there are lesser chances of teeth skipping.

Why Do You Need a Chain Tensioner?
Before we dig deeper into are chain tensioners necessary, let’s first know why it’s crucial to have them.
So basically, the rear derailleur, a bike’s important part, helps seamless changing of gears. It performs this by manipulating the chain tension through a pulley and spring mechanism.
The pulley simply reduces the pressure in the chain while shifting the gear. It then recovers it once the chain comes back to the desired position.
However, the derailleur can become loose over time. And due to this, riders can’t change gears on their bikes as the chain would fall.
The good news is that you can sort out this issue by using a pulley chain tensioner or singulator, if your bike has a vertical dropout frame. This chain tensioner attaches to the derailleur hanger and stretches the chain effectively to ensure proper tension.
Moreover, you can even use a half-chain link for this purpose. However, many bikers avoid this because its replacement procedure is relatively slow and inefficient.
So it’s better to opt for a pulley chain tensioner that offers perfect chain tightness easily, allowing you to enjoy a stable ride.
Existing Derailleur as a Chain Tensioner
While chain tensioners are beneficial, their high price can be a put-off. Considering that, there’s an inexpensive option available as well. In this, you can use your bike’s existing derailleur by transforming it into a simple chain tensioner.
But how? There are two significant ways to do this, but we will discuss only one in this section. Let’s get started.
Use Limit Screws
Here are the steps to convert your bike’s derailleur into a chain tensioner so your bike starts riding at a single speed.
Before you start, we highly recommend using a chain-holding hook to get the best results. It’s easier to make one using an old spoke. Or you can also utilize a large file clamp’s handle.
Here are the conversion steps:
- In the first step, you must detach and remove the shifting cable. This goes along the rear derailleur on your bike.
- Now, you can use limit screws so the pulley lines up with your bicycle’s rear cog.
While performing the above two steps, you must align the chain straight. If not, it can result in inefficient output, leading to an unstable ride. Moreover, the chances of the bike’s components getting premature wear and tear will also increase.
- In the third step, you have to install the bike’s chain through a standard procedure. Also, there’s one thing to take care of. You must bring both sides of the chain together. It should be done in a way that t-pulley is faced forward.
- Now you need to mark the chain’s position so shortening it becomes easier. You can also add one or two links if the tension is on the higher side.
If you want to skip the above method, we also have a budget-friendly option for converting your bike to a single speed.
To do this, you have to keep the existing cassette and chainrings. Now simply leave the chain on the second chainring at the front and in the cassette’s middle region and your bike is ready to ride.
However, there’s a drawback to this method as you can not have savings on the weight. Moreover, the bike will also lack a stylish appearance.

How to Tighten Chain Tension on a Bike?
Keep reading if you want to know are chain tensioners necessary or not, as we will soon discuss that in this article. Before that, let’s learn how you can manually tighten your bike’s chain
If your bike’s chain is loose, our easy-to-follow guide can help you tighten it again. For this process, you will need a few tools and things, like:
- Bike stand
- Socket wrench
- Gloves pair
- Bike lubricant
- Old cloth
Let’s dig deeper into the process.
Note: It only applies to bikes with only one gear.
- Turn your bike upside down to get started. You must ensure that the bicycle’s wheels are in the air. And its saddle should be on the bike stand.
- Now it’s time to remove the screws of the tire so you can easily adjust the chain. For this, you can use a socket wrench and turn the nuts anticlockwise.
- Retract the tire so the chain can move half an inch both ways to ensure proper tension.
- You can check the chain’s tightness by moving your bike forward. If it gets ahead too quickly, then more tightness is needed.
- Once you have the correct tension, it’s time to put back the rear axle by tightening its nuts. Use the socket wrench and move it clockwise to perform this step.
- Spin the pedals to ensure smooth movements of the chain. Finally, test the ride to know whether you have adjusted the chain tension correctly. Or it requires some more work.
Chain Tensioner on Horizontal Dropouts
If you own a horizontal dropout bike, you’ll be less likely to need chain tensioners. But why? Because these types of bikes adjust the chain tension by sliding the rear wheel back easily.
Be it a chain tensioner fixed gear bike or single speed, there’s no need for any extra component for adjusting chain tension in horizontal frames.
Let’s understand its deeper aspect before we move toward are chain tensioners necessary. So basically, horizontal dropouts are of two types. One is rear-facing or track ends, which is popular on the track, BMX, and mountain bikes.
Meanwhile, another type, semi-horizontal dropout, is found on older road bikes. Instead of chain tensioners, you can use chain tugs on these bikes. They wrap around the axle and promote easy tension adjustment.
Are Chain Tensioners Necessary?
In this section, we will briefly cover about are chain tensioners necessary. While they may not always be required, it depends on your bike’s type.
For instance, horizontal dropouts don’t need this additional component. It’s because these bikes have a self-adjusting feature. However, for vertical dropouts, a chain tensioner can become necessary.
Additionally, if you are someone who frequently changes gear ratios, then it can be beneficial. Through a chain tensioner, gear changing can become quicker and simpler.

How to Calculate Bike Chain Length?
For effective bicycle chain tension adjustment, you must first know the length of the chain. It is easy to determine it by following a few simple steps as follows:
- Interpret the largest chainring and cassette cog size on your bike.
- Calculate the difference between these two sizes. For instance, if the chainring is 50 teeth and the cog size is 28 teeth, the difference would be 22.
- Now add 2 to the difference you calculated in the above step. This will make Figure 24.
- Measure the distance between the chainring’s center and the cassettes. You can take this measurement with the chain routed through the derailleur and around the largest chainring and cassette cog.
- Multiply the above measurement by 24. For example, if the measurement is 40 cm, then the calculated results would be 960.
- Now divide 960 with the chain’s pitch. This is typically half an inch for most bike chains. The answer you get would be around 192. This is the recommended number of links for your bike chain.
Wrapping Up
To conclude our guide on are chain tensioners necessary, we would give our final verdict as ‘it varies’. Chain tensioners can provide multiple benefits, such as reducing chain slap and making gear ratio changes easier.
However, this is more suitable for bikes with vertical dropouts. For horizontal dropouts, there is usually no need for a chain tensioner, thanks to their self tension adjusting capabilities. We hope now you have got a clear answer to are chain tensioners necessary.
So take the relevant measure now and convert your bike to single speed to enjoy a stable and fun ride.
FAQs
How to adjust chain tension on bike?
For bike chain tension adjustment, you must first locate the rear derailleur and then turn your bike upside down. Now loosen its rear axle nuts and adjust the chain tension by moving the rear wheel forward and backward. Finally, tighten the nuts, and your bike is ready to ride.
How to check chain tension on bicycle?
For bicycle chain tension check, you can press down on the chain midway between the front and rear sprockets. Make sure the chain moves about 0.5 to 1 inch up or down.
Where should the chain be on a bike?
A bike’s chain runs on the front chainring, freewheel sprockets, or rear cassette.
How does a bicycle chain tensioner work?
It applies pressure to the chain to maintain proper tension throughout the ride. The tensioner uses a spring-loaded arm or pulley to keep the chain tight.
Do you need a chain tensioner for single speed?
It depends on what type of single-speed bike you have. For instance, a horizontal dropout doesn’t need chain tensioners. However, it is required for vertical dropouts or track-style frames.