Tire characteristics depend intrinsically upon the stiffnesses of constituent elements of tread, belt, and sidewall, giving decisive effects on the performances of vehicle motion. Therefore, the analytical study on tire structural mechanics plays an essential role for elucidating vehicle motion. In this paper, deformation and stresses of a two ply folded belt subjected to in-plane bending moment are analyzed, indicating good agreement with experimental results. Then we proved that the in-plane bending stiffness of the folded belt became markedly larger than that of the conventional biased belt. This fact could contribute to enhance the cornering power of passenger tire.