Radial pneumatic tire having contoured zones in the sidewalls

A radial pneumatic tire comprising (1) at least one circumferential reinforcing belt;

• (2) a pair of sidewalls extending from opposing outer edges of said reinforcing belt to corresponding tire beads and containing a single reinforcing cord ply with a turn-up portion around each bead and having respective terminal ends;
• (3) an inner cavity;
• (4) a contoured zone, wherein said contoured zone is (a) located between said single reinforcing cord ply and said inner cavity, (b) circumferentially extending about the axis of the tire, (c) located in a region of from 10 to 50 percent of the distance along the ply contour starting from the outer edge of said reinforcing belt and ending at the terminal end of the single reinforcing cord ply and within this region the first end of said contoured zone terminates about 50 percent of the distance along the ply contour starting from the outer edge of the reinforcing belt and ending at the terminal end of the single reinforcing cord ply and the second end of said contoured zone terminates between the first end and 10 percent of the distance along the ply contour starting from the outer edge of said reinforcing belt and ending at the terminal end of the single reinforcing cord ply and (d) wherein a rubber gum strip is located in said contour zone such that the distance between the single reinforcing cord ply and said inner cavity is greater in said contoured zone in comparison to the distance between the single reinforcing cord ply and said inner cavity in the region beneath said reinforcing belt.