Currently, the main tire construction is the radial construction. The radial construction consists of a carcass layer with cords parallel to the tire cross section and a belt layer which surrounds the tire in the circumferential direction and stiffens the tread band. The radial construction has better performance characteristics than the bias construction. It has higher durability, better wear resistance of the tread, lower rolling resistance, and better performance at high speed because of the stable contact response developed by the belt ply. On the other hand, the belt construction of the radial tire causes ply steer. This ply steer is also a cause of steering pull and uneven tread wear.
This paper describes a new tire construction which enables the reduction of ply steer. The new construction features the carcass cord having some angle with respect to the tire cross section and also with respect to the cord of the adjacent belt ply. It is shown that the new tire construction can significantly reduce ply steer through variation of the carcass cord angle.