Specialized Kicker Sport Tire Black 20 X 2.1Jump, Pump and Wheelie Kicker is game for the streets or bike park. The dense center blocks form a fast rolling strip to give you all the speed you need, smooth block in block transition knobs provide grip and support through turns. We maximized grip but kept the Kicker smooth enough to deliver quiet, and consistent performance. Kicker Sport is available in a wide range of sizes, has a wire bead, and is suitable terrain from street to light trail.