The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread showing our new design, it being understood that a tread pattern is repeated over the outer circumference and shoulder of the tire, the opposite side perspective view being identical thereto; and,
FIG. 2 is a enlarged fragmentary front elevation view of the tread pattern of FIG. 1.
In the drawings, the dark stippled surface shading represents the recessed portion of the tread grooves, having a depth as best shown along the right edge of FIG. 1. The broken line disclosure of a tire sidewall and inner bead is for illustrative purposes only and forms no part of the claimed design.