This video is sponsored by CST Tires.

The main body of a tire is generally referred to as either the carcass or casing. The casing of an original bias-ply tire was made up of layers, or plies of cotton fabric. These plies were laid at an angle to each other, creating the bias which added strength by evenly distributing tension throughout the layers.

The difference with radial tire construction is that the plies are wrapped from bead to bead at a 90-degree angle to the centerline of the tire. In other words, they run parallel to each other, meaning there is no bias, and the plies are joined together, strengthened and stabilized by a belt, creating the original “belted radial” name we are all familiar with.

As technology improved, cotton was eventually dropped for the use of better materials such as nylon and polyester in the plies and steel for the belts of a radial.

Each type of tire construction has its pros and cons.

With bias ply tires, because the tread and the sidewalls share the plies of the casing, the entire body of the tire will flex as a whole, providing better grip and clean-out, excellent side-to-side or lateral stability and excellent durability for tough, rocky terrain and heavy loads.

They are typically less expensive, but they also wear faster with greater rolling resistance, have a smaller foot print and provide less traction.

Radial tires last longer and have lower rolling resistance, better high speed and handling capabilities and provide a larger footprint and better traction. They are typically more expensive.

For almost any application, you’ll find a bias or radial option. Every tire buying decision is based on a lot of factors, and demonstrating this knowledge to your customer will give them confidence in your recommendation.