The ultimate BMX racing tire, the PowerBlock is designed to efficiently transfer pedal power and other rider inputs into lateral motion. In short, you'll roll faster with less wasted energy. The S-Spec version utilizes Tioga's thinnest sidewall for maximum suppleness and weight savings. Size for size, the PowerBlock S-Spec are the lightest BMX tires in the world. PowerblockAll the sweet goodness of the PowerBlock S-Spec, but in steel bead with thicker, stronger sidewall. The standard PowerBlock strikes the sacred equilibrium between performance and value. Center row“Power Blocks” are precisely sized to balance traction with low rolling resistance. Sidewall textureSpecially designed texture pattern, strategically applied to the sidewall adds abrasion protection without sacrificing casing suppleness.