Torque Wrench: Advantages and Disadvantages of Torque Management

What is “torque”?

The word “torque” is often heard in road bike and MTB maintenance. Torque is “torsional strength” and refers to the amount of force used to tighten a bolt or screw.

The unit of torque is expressed in N-m (Newton meters), and sports bicycle parts and manuals specify the tightening torque for installation.

A torque wrench is a wrench that can manage torque.

Functions and types of torque wrenches

There are many types of torque wrenches. In terms of function, there are three major differences.

1. idling at a specified torque / only measuring the torque value
2. changeable torque value / fixed torque value
3. measurement method is analog / digital

The first major difference is the behavior when the specified torque is reached. Torque wrenches that do not have a idling function and simply measure are inexpensive, but depending on the addition or subtraction, there is a possibility that the torque may be tightened beyond the specified torque.

In addition, some torque wrenches allow setting of torque values, while others do not. Most torque wrenches for maintenance can change the torque value in detail, but many portable torque wrenches are the type that idles at the torque set in the product, such as 5 nm. It is small and convenient for carrying, but it is not capable of fine torque management.

Finally, there is a difference in measurement method. Most torque wrenches set the torque value by analog, but some models display the current torque value digitally and inform you with a beep sound when the set torque value is reached.

Which torque wrench to choose depends on the application and the accuracy of maintenance you are looking for, so you will have to consult with your budget to choose the best one.

Difference between a torque wrench and a torque wrench

A wrench with a similar name is called a “torque wrench,” but they are completely different.

As explained earlier, the “torque” in a torque wrench refers to the strength of tightening, while the “Torx” in a Torx wrench is a standard for hexagonal star-shaped screw heads developed by the American company Textron Kamker.

Torx is characterized by the star-shaped screw head and is called “star-shaped screw.

Therefore, a Torx wrench cannot be used to control the tightening torque on a road bike or MTB.

On the other hand, if you have a torque wrench with an interchangeable pit, you can manage the tightening torque of Torx screws by preparing a Torx pit.

Advantages of torque management

The advantage of torque management is the ability to optimize the tightening of parts.

Each part has an optimum torque value recommended by the manufacturer, and this value is set to “prevent the part from coming off without breaking the part,” thus increasing the reliability of the part’s assembly.

In addition, carbon products such as carbon frames, carbon seat posts, and carbon handlebars are vulnerable to strong force applied to a single point, so there is a high possibility of cracks in them if they are tightened with more than the torque specified by the manufacturer.

This is why it is said that “torque management is essential when using carbon parts.

Disadvantages of using a torque wrench

Although torque wrenches have many advantages, they also have disadvantages.

First, the wrench itself is expensive. While you can get a high-quality set of common Allen keys for as little as $30, most torque wrenches cost around $100. Even if it is for your precious bike, you may hesitate to pay $100 for a tool that you do not use often.

Another disadvantage of torque wrenches is that there is a possibility that the measured value will shift with continued use, or that the torque value may not be accurate depending on the manufacturer.

If the torque value becomes misaligned, it is possible to overtighten and crack the wrench if it is tightened as specified by the torque wrench, so it can be said that there are unexpected risks lurking.

Torque wrenches can become misaligned with frequent use, and low-quality torque wrenches may not give the correct value when you buy them. For this reason, professional stores usually install torque wrenches from manufacturers who are sure of their quality, and after a certain period of use, leave the wrenches with the manufacturer to have the torque corrected. In other words, torque wrenches require “servicing the wrench itself”.