Gorilla ATV Silverback Mud Tire (30x11-14) The Gorilla Silverback ATV Mud Tire is easy to describe. It's simply the most aggressive ATV tire in the world. There is NO other tire on the market that compares to the size, tread, sidewall wrap, design, cleaning properties, and sheer "BADNESS" of the Silverback. The great tire designers in the sky really did it right when they designed the most intriquite design known to man. And then called it Silverback.