What is a Chainsaw Sprocket? Chainsaw Basics Explained [2023]

chainsaw sprocket basics explainedA sprocket is one of the most important parts of a chainsaw. It is responsible for the torque supply to the chain which ultimately leads to its rotation. Thus, as you are already aware, the basic function of a chainsaw is to cut, which is achieved through the rotation of the chain.

It is very much needed and crucial to maintaining sprockets. The reason is that that’s how you will get the maximum power and work efficiency from the cutting tool. In this article, I will guide you regarding what is a chainsaw sprocket in detail.

This will help you better understand the function and importance of the drive sprocket. So, be with me and learn in-depth about your chainsaw and its parts, specially sprockets in this article. Let’s get started.

What is Chainsaw Sprocket? The Basics Explained in 2023

First, let me tell you what a chainsaw sprocket is in terms of its working and functions. It works by providing power to the chain from the crankshaft and as a result of the power the chain rotates. The rotation of the chain results in the working of the gas chainsaw.

The sprocket is joined with the clutch drum and crankshaft. The rotation of the sprocket is on the same axis as that of the clutch drum and crankshaft. In the process of cutting, the chain, sprocket, guide bar, and clutch drum are of great significance.

Drive sprockets move the chain by gently pressing the teeth against it and that is how the kinetic energy of the engine is transferred to the chain. If your chainsaw is skipping or jerking, the reason is worn-out sprockets. Keep on reading till the end and get in-depth information regarding the chainsaw sprockets.

Chainsaw Sprocket Size

There are different sizes of chainsaw sprockets to be used according to the chainsaw. In most of the pro saws, 325”, 3/8” or 404” sizes are used. However, you must also take into account the number of teeth. For instance, for a pitch of 3/8”, both 3/8″ X 7 and 3/8″ X 8 sprockets can be used efficiently.

Types of Chainsaw Sprocket

I have provided you the information regarding the working of sprockets and what is their significance. Now, let me tell you that chainsaw sprockets are of two types mainly. This statement will surely click one question and that is which is better? Right? I will answer your question but before that, you should know the difference between the two.

The basic purpose of both types is the same and the principle is also the same. Like, both types use power from the crankshaft and utilize it to rotate the chain over the bar. However, there is a difference in their style and shape which leads to a slight difference in their working patterns and that’s where the controversy starts.

Spur Sprocket

A spur sprocket is of the star shape and usually has 6 or 8 edges. It is directly attached to the chainsaw’s clutch drum. The clutch supplies power from the engine to the sprocket over which the chain rotates and cuts. A spur sprocket is also called a hub sprocket.

Rim Sprocket

A rim sprocket has a gear shape and it also has 6 or 8 edges which again makes a multipronged star-like shape. It has two layers that make channels over which the chain moves. It is free floating and the clutch supplies engine power to the splined hub over which the rim moves and it facilitates the rotation of the chain by providing power for rotation.

Difference Between Spur and Rim Sprocket

The spur sprocket is way more simple and easy to maintain as compared to the rim sprocket. The main difference between the two types is in the method that they follow to transfer heat. This primary difference is what makes the discussion of spur vs rim sprocket a matter of concern.

The terminology of Rim and Spur sprocket is different and for which the method is also different. A Spur Sprocket has a simple terminology by having Drum Skirt, Clutch, and Bore. While The Rim Sprocket has a complex terminology that includes, Rim Sprocket, Clutch Drum, Splined Hub/ Adaptor, and Bore.

Which Type is Better to Use?

Now that I have explained to you the difference between both types it is time to answer your question that which type is better. So, choosing the sprocket depends upon the type of chainsaw. Most chainsaws come with spur sprockets while sometimes you get this option to choose by yourself if your chainsaw supports a rim sprocket.

Both of the types have their own advantages and disadvantages as well. Spur sprocket is believed to be easily maintained yet some users claim that Rim sprocket is also easy to be maintained and even changing the Rim sprocket is quite easy.

A Rim Sprocket is believed to be of great advantage in many terms like it is cheaper than the Spur Sprocket. Moreover, it also protects the chain from great wear and gear along with maintaining a good grip over the chain. Resultantly, the chain runs smoothly over it. Thus, it can be said that a Rim Sprocket is better than Spur/Hub Sprocket.

When to Replace Chainsaw Sprocket?

There are some indications that you need to notice and they will tell you that it is time to change the sprockets. The first sign is if your chainsaw chain gets loose quickly, you must check if the sprockets are worn out as this can be the reason for the chain coming out frequently.

Secondly, look for visual signs such as inspecting your sprocket and if the surface is not smooth, it is time to change the sprocket. This usually occurs in the case of spur sprocket. Moreover, you may feel vibrations and hitches in the operation of the chainsaw. This can also be an indication of worn-out sprockets.

Frequently Asked Questions:

How do I know if my chainsaw sprocket is worn out?

There are many signs that you can look for to know if it is time to replace sprockets. Operational signs such as vibrations and hitches are also signs for worn-out sprockets.

Other than that, a visual inspection of sprockets will also let you know if they are worn out. Frequent chain slips are also signs of worn-out sprockets. All of these methods will let you know if your chainsaw sprockets are worn out or not.

What is a chainsaw rim sprocket?

A chainsaw rim sprocket is one of the two types of chainsaw sprockets. It is structured in two layers, one is attached to the clutch and the other is fixed on it. The chain moves over the clutch cover’s hub. It is a multi-pronged one that has a star shape with either 6 or 6 edges. This type is believed to be better than the other one because of its efficiency.

How often should you change a chainsaw sprocket?

A thumb rule for this is to change sprockets when you replace a chainsaw chain for the second time. Or else change sprockets when needed and you can get to know this by observing your chainsaw operations.

Do different chainsaws have different sprockets?

No, both types can be used for the chainsaw. However, if your chainsaw does not support a rim sprocket then you have to go with a spur sprocket. Other than that there is no such restriction regarding the specific use of sprockets for specific chainsaws. Your chainsaw might come with a spur sprocket but you can replace it with a rim one.

What is the function of the sprocket?

The function of the sprocket is to serve as the platform for the chain rotation. The chainsaw chain is placed over the sprocket. It rotates on the same axis with the crankshaft and clutch which in turn rotates the chain. The moving chain then cuts the wood and the job gets done.

Final Takeaways: What is a Chainsaw Sprocket?

This was a detailed guide about what is a chainsaw sprocket. I have covered all the possible areas related to the topic for you. This is all that an average user of the chainsaw should be aware of to get the best out of this cutting tool.

I have shared with you in-depth and clear information regarding chainsaw sprockets. Hopefully, you have got a better understanding of the working and importance of chainsaw sprockets.

Along with this, you have also got to when you should change the sprockets and their importance.


Richard McMann

Richard lives out in the wild with his other half, Diana Richard. He tests chainsaws based on his personal experience and loves to share their nitty gritty details with his audience. Although Richard does focus on other home improvement tools, his focus remains on cutting fallen trees or maintaining his backyard via chainsaw tools. He pledges to come up with new knowledge about chainsaws every once in a while.