Why Is A Chain Speed Tensioner Necessary? [Purpose And Length]

If you’ve been biking some time then chances are you’ve met a few gear heads talking about tensioners.    These things often don’t come on your default bike gear sets and are an addition.  Is a chain speed tensioner necessary?  Well, it really depends.    It basically comes down to your vertical drop out (of your chain) and the rear derailleur.

Once you get the hang of the gear set and the tensioner you can focus on getting the best pedals but for now let’s dive into a single-speed tensioner.

Do You Need a Chain Tensioner for Single Speed?

If you’ve recaptured your youth and have opted for a single-speed bike, then you might not have known that it comes with some nuances that you didn’t expect.  Being an owner of a single-speed bicycle means you are not relying on switchgear, shifters, and cables. Unfortunately, changing out gears doesn’t immediately simplify the overall bike’s mechanics.  

Most people experience loss of chain tension due to the removal of a rear derailleur.  In addition, tensioners can help if you have other things affecting your vertical drop out.    Honestly, the biking community is split on this one.  The reality is that most people like the simplicity of the single-speed chain set up and adding a tensioner adds to the complexity.  However, if you’re a real gear head and want to keep some of your setup but opt for a single-speed run, a tensioner is a must-have. 

The Purpose Of A Chain Tensioner

The rear derailleur is responsible for switching the chain tension while shifting to a new gear. During this, a pulley progresses through the spring mechanism and decreases the chain tension.

The bicycle chain keeps on dropping all the time due to the absence of this feature. As a result, it becomes difficult to change gears.   Again, as mentioned, tensioners are an add-on to keep your gears tight and if you run your bike hard, they’re a great investment. 

No Need for Chain Tensioner?

Complexity is keeping some people from buying chain tensioners. However, you could convert the existing derailleur by reducing it down into a simple tensioner. 

How To Reduce Your Derailleur

Limit Screws only. There Are Two Methods To Do This.

  1. Limit Screws and Cables.

Limit Screws Only

Step no 1. Remove the shifting cable behind the rear derailleur.

Step no 2. Adjust the pulleys to the rear cog with the help of limit screws on rear derailleur.

Step no 3. Install the chain and bring both sides together until the t-pulley is positioned forward.

Limit Screws And Cables

Cut the cable linked to the rear derailleur into a short piece instead of removing it. Through the barrel adjuster at the back of the derailleur we can micro-adjust the position of the pulley.

Keeping in mind that you can use any derailleur you want as long as you can attach it to your bike. Moreover, if you want more clearance and reduce the chances of catching an external object go for a short cage.

Optimal Chain Length

Freshly, a bicycle chain includes 116 linkages forming one of the biggest chainrings. Shortening the new chain can assist in achieving the ideal chain length.

In the case of touring frames, for example, with lengthy chainstays, more links need to be added for a perfect length.

Why Is It Important To Discover The Exact Chain Length For Single Speed?

Elongated chains have more probability of dropping, while short ones can be destructive for the drivetrain.

Discovering The Ideal Chain Range

The chain length should be flexible for bicycles without derailleurs and chain tensioners to some extent. 

This allows such bikes to have a fixed speed or gear but rear hubs on some bicycles have different speeds and gear ratios. But still, the chain measurement method is the same for both.

Do Horizontal Dropouts Require A Chain Tensioner?

There is no such need for a pulley chain tensioner in horizontal dropouts. The rider creates chain tension by sliding the wheel backward.

Types Of Horizontal Dropouts

Two Types Of Horizontal Dropouts.

  1. Front-facing dropouts
  2. Track Ends

The frames with track ends are better in terms of safety and comfort. During a typical mountain ride, your bike will absorb a heavy amount of shock and pressure.

The bike equipped with these frames does not rely on spring-loaded chain tensioners but some people install chain tugs. This tool sometimes acts as an alternate to the chain tensioner and blocks the rear wheel from moving forward into the dropout.

The second type of horizontal dropouts is also known as “semi-horizontal” .

They were mostly used in the mid and late of 19th century. These Frames were professionally positioned for bicycles with rear derailleurs and allowed people more manipulation regarding chain tension because they were long.

This ultimately means that,the longer the dropouts,the better they perform. Due to old age and inaccessibility, these frames are pricey hence single-speed conversions have gained more fame nowadays.

Is A Chain Speed Tensioner Necessary?

Our take is that if you like tinkering with your setup or have tension issues then yes!   You should head over to read our reviews.    If you prefer the simplicity of something like single-speed setups then you likely can pass on this one.

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