Vittoria Barzo XC Race Tire - 29 x 2.40, Tubeless, Folding, Black, Race Graphene + SilicaAlternating center knobs of the Barzo XC Race tire are designed to roll fast, and the moto style shoulder knobs bite hard while cornering. Siping throughout increases grip under lateral loads, helping to maintain speed across terrain of all types, and spacious knob placement cleans muck and loamy soil. The Barzo XC Race is perfectuly suited for coarse loose terrain conditions. Race Formulation: Graphene + Silica Compound provdes speed and grip without