Pneumatic radial tire carcass line profile

摘要

A pneumatic radial tire comprising a carcass layer (4), a tread portion (1) and a belt layer (6) disposed therebetween, the belt layer (6) having a structure composed of at least two layers, wherein said belt layer is formed at least at a central portion of the cross section thereof to have a parallel portion (7) substantially parallel to the axis of rotation of the tire over a width (Wp) corresponding to 30 to 50% of the maximum width (W) of said belt layer; and said carcass layer (4) is formed in such a manner that when the tire is mounted on a rim and filled with air to 10% of a normal internal pressure, a portion corresponding to the parallel portion (7) of said belt layer has a profile of a carcass line joined parallel to said parallel portion (7) and a portion tangentially extending from the edge (A) of said parallel portion (7) and leading through the maximum width portion (B) of the tire to at least the upper edge (C) of a bead filler (9a