Speedboard Injection molded nylon-blend Speedboard for an energetic and responsive ride. Upper Made using a single piece of flat-knit engineered mesh, the breathable upper has a snug, sock-like fit that adapts to a wide range of foot shapes. Midsole / outsole The new dual-density midsole is made with two types of HelionTM superfoam – for soft landings and powerful take-offs.