Ramped and siped, the center tread blocks provide maximum traction and accurate steering. The sawtooth-faced shoulder knobs offer a continuous biting edge for railing through corners.Specialized's GRID TRAIL casing is a step up from GRID with more reinforcement, delivering better handling at lower pressuresall while increasing pinch flat protection by 15% and puncture protection by 30%. The high-dampening GRIPTON T9 compound rebounds slowly to grip and stick to the ground for total traction and control.