A bias ply tire is a type of tire construction where layers of fabric, known as plies, are laid at angles to each other, typically at 30 to 40 degrees. This design provides a flexible sidewall, which can enhance ride comfort and traction on various surfaces. Bias ply tires are often used in classic cars, vintage vehicles, and some off-road applications. These tires are generally less expensive than their radial counterparts, but they may wear out faster and offer less stability at high speeds. While they are suitable for certain driving conditions, many modern vehicles now use radial tires, which provide better performance and fuel efficiency.