Straight Cut Gears vs Helical: What Are the Differences?

Straight cut gears vs helical gears comparison will examine the differences between the two designs. Gears usually come in different sizes and shapes and can be used for different applications.

Straight Cut Gears vs Helical

However, these two gear types are the most common types of gear used in motorsports applications worldwide. We’ll highlight their differences, key features, functions, advantages, and disadvantages below, so read on!

Features Straight Cut Gears Helical
Thrust Load The gear produces minimal thrust load along the gear shafts due to its simple design. The gear produces higher thrust loads resulting from the added strength of the internal parts and gear housing.
Operating Efficiency Delivers less sliding action, which brings about lesser loss of energy, and increased operational efficiency. The operating efficiency of gears that are helical is lower due to the heat that is lost when gears engage.
Cost The manufacturing process is simple due to their simple design, and this makes them less costly. The manufacturing process is complex and usually requires computer-controlled processes. This makes the gears more expensive.
Noise The gears produce more noise and are only suitable for racing applications. The gears produce lesser noise, which makes them suitable for application in passenger vehicles.


What Are the Known Distinctions Between Straight Cut Gears and Helical?

The known distinctions between straight cut gears and helical is where they are used. You’ll find helical gears on a regular city driving car, and this is because they are generally smoother and quieter. The straight-cut gears are mostly used on monster trucks or for racing applications.

There are many other differences between the two gears, especially in terms of their mechanics. Because of how they are applied, you might want to think straight gears are stronger than their helical counterparts. Even though they provide high performance and power, they are, in fact, the weaker gear. This is because gears that are helical provide a stronger load-bearing surface since they hold more teeth.

Therefore, for racing applications, straight gears will give you the best performance, but if you’re after a quieter and smoother mount, the helical alternative is the better option. Gears that are helical have angled teeth, and this makes it easier for them to take heavy loads. Also, gears that are helical effectively transfer more power through straight angles and parallel axis to offer a smooth run.

Another thing worth noting is that the heat generated by helical is more, and this requires an efficient lubrication system to minimize wear and tear. However, when compared to straight gears, helical gives lesser wear and tear, which makes them last longer. When it comes to maintenance, helical require more maintenance than straight cut gears.

How They Work

The way the gears work is another factor that distinguishes them. Basically, straight gears move around, and this causes an increase in friction as they push into one another. The increased friction then brings about a corresponding reduction in the transmitted power, thereby resulting in a drop in torque. Also, this creates a safe condition for the transmission fluid.

If your vehicles currently feature the helical setup and want to convert it to the straight setup, you can do that easily. In general, it’s easier to convert the helical setup to the straight setup, but that’s not the case when you want to go from a straight-cut gearbox to a helical.


The level of efficiency you get from your gearbox setup depends on the practicality and scenario you use it. Therefore, it’s important to note that straight gears don’t offer much practical use, unlike the alternatives.

If you plan to hit the track with your vehicle, the practical option to use is the straight gear setup. This is the best option because of the loss of weight and excess heat and reduced thrust force it provides. With that, you can rest assured that your car will perform optimally whenever you hit the track.

Comprehensive Overview of Straight Cut Gears

Straight cut gears are also called straight spur gears, and it’s one of the most common types of gears used for mobile applications. The gear looks like a straight gear teeth interlocking with other gears and evenly placed around a circular body. They have a simple design and are cost-effective.

Features of Straight Cut Gears

As mentioned earlier, they consist of straight gear teeth, which are aligned parallel to the mounting shaft. Also, accurate machining processes are applied to ensure that the teeth are profiled precisely. The materials used in the manufacture of the straight gear setup include extremely hard and high-strength surfaces to ensure that it offers a long lifespan.

One of the fascinating things about straight gears is that when they engage, only a single pair of teeth carries a load at a time. Also, when two gear teeth touch, it’s usually parallel with the shafts and in a straight line. This impact leads to the generation of sound, and the volume and frequency of this sound usually increase as the gear sound increases.

When subjected to load, the straight gears usually create a force that pushes the gears apart. This is why they feature support structures that can oppose this force.

Benefits of Straight Cut Gears

Straight gears offer multiple benefits, which include the following:

  • They age less costly because the teeth of the straight gear are machined in a straight line and parallel to the centerline. This makes the process of manufacturing and its overall design simpler.
  • The sliding action of straight gears is also lower, and this causes lesser energy to be dissipated, ultimately increasing the efficiency of the gear. In racing vehicles, this increase in efficiency helps to generate more speed and power at the rear wheels.
  • As mentioned earlier, the gear doesn’t produce much thrust load at the gear shafts, thanks to its simple design. This also helps to reduce the size and weight of the gearbox housing, which is vital for racing and sports cars.Benefits of Straight Cut Gears

These are the amazing benefits of the straight gear setup, but it’s important to note that with this setup, you get higher noise. The noise produced is one of the main reasons why they are not a great option for use on passenger vehicles. Noise is not an issue of concern for racing applications, but for city applications, it may go against specified driving laws in your jurisdiction.

Comprehensive Overview of Helical Gears

Helical gears are helical in shape, with helical teeth that are obliquely arranged. This gear setup is designed to transfer more force than the straight counterparts. They also produce an axial thrust, but this can cause an issue if the axial force is not effectively absorbed.

In the helical setup, the teeth are arranged in an angled pattern based on the direction the gear rotates. This is usually between 15 to 30 degrees, depending on the vehicle. After engaging the gears, they first touch each other, and the contact point then moves along the surfaces of each tooth. This is usually with lower impact, unlike that of the straight gears.

Specifications of Helical

Another thing to note is that, unlike the straight gears, more than one teeth pair is engaged at a time. The angular design of the gears is also a unique feature, and this facilitates quiet operation, even when subjected to the same load-carrying capacity and speed as straight gears.

One of the similarities they share with spur gears is that they also create a separating force when operating. However, they also produce an extra thrust or axial force on each shaft. Therefore, with increasing gear, the load equally increases.

The housing of gears that are helical, as well as their internal parts, needs to be designed to cater to the thrust loads they produce. This further increases the size and weight of their housing, making them unsuitable for racing applications.

In addition, gears that are helical usually generate more heat, and this is a result of the friction from the sliding action. This heat causes a reduction in the efficiency of the gearbox. In some cases, there’s a need for an oil cooler because the lost energy usually increases the heat of the lubricating oil. All of these conditions are not ideal for racing applications.

Benefits of Helical Gears

Helical gears offer multiple benefits, which include the following:

  • The most notable benefit of using gears that are helical is lower noise. This type of gear only produces 12 Db(A), which is lesser than straight gears of the same size. With this gear, you enjoy quiet operation, whether it’s in a passenger vehicle or other equipment like a washing machine.
  • Another benefit of using this type of gear is its lower weight. This is because the load is usually transferred over 1.5 gear teeth, and it helps to enhance its efficiency.Benefits of Helical Gears

Despite these amazing benefits, there are a few drawbacks of gears that are helical, and it’s important to note these drawbacks. The first is that they are mostly available at a higher cost due to their complex machining and design. Their design usually requires computer-controlled machining centers, which increases costs.

Another drawback of the gears is that when compared to straight gears, they offer lower operating efficiency. This is due to the high heat that is produced when the gears are engaged. The heat loss causes a significant reduction in energy and absorption of the lubricating oil.

Gears that are helical also require heat exchangers to ensure that the lubricating oil stays cool. This is undesirable in racing vehicles because they need enough power for optimal operation.

Finally, the thrust loads in gears that are helical are another drawback to note. As mentioned earlier, these gears generate thrust loads, and the internal components are gear housing designed to withstand the load. It also increases the size and weight of the gearbox design, which further makes it unsuitable for racing applications.


With everything above, you should now understand the differences between the two gear setups and their respective applications. The two gear systems have different features and designs, but the most important thing to consider when choosing is how you plan to use your vehicle. The cost of each gear setup is also a factor that can influence your decision when choosing between the two gear types.

For emphasis, straight gears produce more sound and operating efficiency, which makes them the preferred option for racing applications. However, for regular city driving, the preferred option is gears that are helical. This is because they produce less noise but note that they are more expensive due to their complex design.


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