Variable Pitch Tread Pattern Advanced sound equipment was used to create a pattern that provides a quiet and smooth highway ride. Shoulder & Lateral Z Grooves Shoulder grooves are arranged in alternating widths and lengths to clear mud and maintain traction. Lateral Z grooves are set in a zig-zag pattern to provide biting edges for traction. Dual Sidewall Like all Grapplers, the Ridge Grappler features two bold sidewall designs. One side features a more traditional pattern while the other side features a new, aggressive block design.