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How Wheel Chocks Work

Choosing Wheel Chocks
Wheel chocks are designed for different types of tires and vehicles.
Wheel chocks are designed for different types of tires and vehicles.
Joe McBride/Getty Images

Wheel chocks are a relatively cheap investment in your safety and the safety of others. Anyone who's shopped for chocks knows there are a variety of options available on the market. So which one's best for you?

Wheel chocks are manufactured in different shapes and out of different materials. All, however, are inclined planes; if used correctly, each should perform the job. Since all chocks provide a hill for a wheel to climb if it wants to roll, it doesn't matter if it's two inches or two yards high. That lack of difference pertains only to a perfect wheel, though, and tires aren't perfect wheels. They can change their shape. Tires aren't rigid, so a tire can bend around a small enough chock and continue on its roll downhill. In the case of selecting a wheel chock for tires, the bigger the better. Many chock manufacturers also specify what tire height their chocks are designed to accommodate.

Both metal and synthetic materials are often used for wheel chocks. Aluminum chocks are often designed with teeth on the bottom, which bite into the surface below and provide stability. Synthetic or rubber wheel chocks provide stability through the friction created between the non-slip material and the ground. Just about every manufactured wheel chock also has some kind of tread on its face to produce friction between the tire and the chock. Additionally, some chocks are designed with a curve that hugs the shape of the tire. Others are simple pyramids or may have a lip at the bottom to wedge firmly between the tight spaces where the rubber of the tire leaves the road.

All of these wheel chocks should do the job, but there are other requirements you'll want to take into consideration when selecting chocks for your vehicle. Because weight and gravity combine to force a wheel downhill, be sure you've got a wheel chock that can stand up to the weight of your vehicle. Most chock manufacturers specify what weight their chocks can accommodate, so be sure to check how much your vehicle can handle before purchasing.

The type of vehicle and tire you plan on chocking also make a difference in the chock you choose. Heavy, off-road tires used on large equipment like earthmovers and grading equipment require a different chock than your family sedan. Check the package to find out what kind of vehicle the chocks you're purchasing were designed to accommodate.

Now, you've done your homework and purchased the wheel chocks that are right for you. Read the next page to find out how to properly use them.