crossply

Crossply, or bias-ply, refers to a type of tire construction in which the internal cord plies are laid at alternating angles to the wheel’s circumference, creating a crisscross carcass. In traditional crossply tires, the body plies are typically arranged at angles of about 30 to 40 degrees to the circumference, with plies crossing over each other. Some crossply tires also employ a belt or cap ply to stabilize the tread area, but the defining feature remains the cross arrangement of the carcass plies.

Historically, crossply tires were standard in the automotive industry for much of the early to mid-20th century. They were gradually overtaken by radial-ply tires, which use cords running nearly perpendicular to the circumference and are typically reinforced with belts under the tread. Radial tires generally offer improved ride comfort, handling, heat management, and fuel efficiency, contributing to the decline of bias-ply designs in mainstream passenger vehicles. Nonetheless, crossply tires have remained in use for certain niche applications, such as vintage or classic cars, and in some off-road or specialized equipment where their specific characteristics are advantageous.

In practice, the choice between crossply and radial tires involves trade-offs among ride quality, durability, rolling resistance, and cost. Crossply tires tend to have a stiffer feel and higher rolling resistance compared with radials, while radial tires provide a smoother ride and more uniform wear. The term crossply is most commonly encountered in discussions of tire history and legacy vehicle technologies.