True strict enough to deal with high speed roughness and without resistance, but sufficiently square and high to be sinking at best when it is time to brake abruptly. A rounded profile and staggered and supported lateral pieces continue to ask for traction even when the path loses its belling. The light/fast rolling has a compound of the fast and efficient central tread combined with adherent lateral pieces and low hardness that cover a flexible and attentive carcass, designed to be cushioned without sacrificing performance on the paths.