The XCO World Champion tire Riding technical XC? The Barzo is the choice of the 2015 World Champion, as well as the winner of the BC Bike Race. How can such an aggressive XC tire roll so fast? The magic starts in the center tread, where we place an alternating ridge design, and progressive sipe angles. Cornering duties are handled by the moto-style block knobs, laid out in a proven V-formation. The result is a tire that corners as fast as it rolls, while still offering the protection of a full depth tread. Rocks and roots? Check. World Championship? Check.