What is a Snowmobile and How Does it Work?

If you’re looking to travel over snow and ice, whether it’s for transport or recreation, a snowmobile is the way to go. 

This page will cover the basics of snowmobiles – what they are and how they work.

In other pages in our Snowmobile section, you can learn more about things like how to ride them, what gear you’ll need, how much they cost, and how to do your own maintenance and repairs. 

What is a Snowmobile?

Snowmobiles, which are also referred to as Ski-Doos, snow machines, or sleds, are motor-driven vehicles that are designed to travel over snow and ice. 

Snowmobiles feature a chassis, saddle seat, and handlebars. The rider straddles the seat like they would sit on a motorcycle and steers the vehicle with handlebars.

Most snowmobiles feature two skis in the front and are driven by a track in the rear. 

State Department of Motor Vehicles and Parks/Wildlife Departments generally define snowmobiles as:

• Vehicles driven by mechanical power that are designed to travel on snow or ice.
• Supported by skis, belt tracks, cleats, or sled-type runners.
• Having a GVWR of no more than 1,200 lbs. 

Many states have separate classifications and regulations for snowmobiles instead of grouping them in with other off-highway vehicles (OHVs or OHVRs). Some states require snowmobiles to be licensed and registered, while others may not. 

Snowmobiles are used for transportation and travel in areas with cold, snowy winters, and they’re also a popular vehicle for winter recreation. 

First introduced as utility vehicles, snowmobile recreation has grown in popularity to include activities and events like touring, trail riding, winter fishing and hunting, racing, and freestyling. 

When was the Snowmobile Invented?

The origins of the modern snowmobile can be traced back to the early 1900s, when inventors were using track-driven vehicles to ride over snow and icy terrain. 

In 1915-16, Ray H. Muscott received Canadian and US patents for a vehicle driven by a rear track and front skis. The design was popularly used to modify Ford Model Ts to get around in the snow. These modified trucks were known as “Snowflyers.”

By 1917-18, Virgil D. White patented a snowmobile conversion kit for the Model T, which became available for sale directly through Ford dealerships. 

In 1935, Joseph Bombardier, founder of Bombardier, created the first iteration of the modern snowmobile with fixed skis and a rear track. Many of the first snowmobiles were designed to carry multiple passengers over snow and ice. 

By 1959, Bombardier refined his design and released the Ski-Doo, which became the first commercially successful, modern snowmobile. 

The open, motorcycle-like saddle design became popular, and by the 1970s, there were over 100 different snowmobile manufacturers. 

How Does a Snowmobile Work

Most snowmobiles are powered by either a 2-stroke or 4-stroke combustion engine. 

A snowmobile works with the combinations of 4 main parts, which include:

• The engine. 
• The clutch mechanism. 
• The track band. 
• The skis. 

The snowmobile is driven forward by the engine, which sends power to the clutch and rear track drive, which then rotates the track and moves the machine forwards. 

The handlebars and forward skis are used to steer, stabilize, and control the vehicle. 

Main Parts of a Snowmobile

As mentioned above, the main parts of the snowmobile that make it work include the engine, clutch, track, and skis. 

Aside from that, you’ll find many of the same parts that you would find on a motorcycle, dirt bike, or ATV. 

Below, we’ll describe how each of the main components of the snowmobile function to make it all work. 

Snowmobile Engine

The snowmobile’s engine is similar to that of a motorcycle or ATV. 

Depending on the snowmobile, it may feature a 2-stroke or 4-stroke engine. Newer snowmobiles may even feature electric-powered engines. 

The engine works in conjunction with a carburetor or fuel injector, which draws a fuel/air mixture into the combustion chamber, compresses the mixture, ignites it, and repeats the process to send power to the final drive. 

Transmission and Clutch System

Snowmobiles feature a clutch system known as a CVT, or Continuously Variable Transmission. 

This type of transmission features a primary and secondary clutch connected by a chain or belt. 

The primary clutch is rotated by the crankshaft, and the secondary clutch is rotated by the chain/belt and connected to the track drive. 

As the crankshaft rotates and RPMs increase, the primary clutch is activated and begins to rotate as well. At idle, the primary clutch remains stationary. 

The secondary clutch connects to the track drive, which is designed to control the gears that are responsible for moving the rear track. 

At higher speeds and engine RPMs, the clutch engages and disengages as necessary to send the appropriate torque and power to the final drive. The design relies on centrifugal forces, cams, and drive gears to power the snowmobile’s track as needed. 

Snowmobile Track

Snowmobile tracks are typically made of rubber and reinforced with carbon fiber or Kevlar. 

They are similar to tracks you’d see on tanks or bulldozers, and are a continuous loop that feature traction, studs, and ridges to grip to snow and ice. 

The design of the track allows it to spread the vehicle’s weight over a great area, which gives it a better ability to travel and be controlled over soft or slippery terrain like snow or ice. 

As the engine powers the transmission, the track is rotated by a set of gears, chains, and idlers, which ensure the track rotates in alignment and maintains the proper tension at different speeds. 

At lower speeds, the track typically has less tension to provide better grip and traction. At higher speeds, the track tightens up. 

Skis and Handlebars

Snowmobiles are steered with a set of two forward skis that are controlled by handlebars similar to those found on a motorcycle. 

The handlebars connect to a steering neck, which attaches to the forward suspension and ski brackets. 

Pointing the handlebars in a certain direction will turn the skis in that direction. 

The snowmobile’s skis can come in a variety of lengths and widths, depending on the terrain you’ll be riding on. 

As speeds increase, the rider will need to shift their weight and use the handlebars to initiate and complete turns. 

Like the track, the skis help to distribute the snowmobile’s weight over a larger surface area. 

Now that you understand the main parts of the snowmobile and how it works, you’ll be ready to learn to ride one.