Plenty of testing went into the Pro4 Comp with the goal of squeezing out every last bit of speed. A dual-compound tread with a fast-rolling center and softer shoulders offer amazingly sticky cornering, and its puncture-resistant tread provides impressive durability as well. The supple 150 thread-count casing ensures a smooth, efficient ride. And, the Pro4's incredibly feathery weight is just the thing for shaving seconds and topping the next hill ahead of the competition.