Saturday, August 16, 2008
Nike's Flywire:Borrowed from anatomy
Another potential record breaking shoe is the Zoom Victory spike from Nike which took seven years to develop. It is a lightweight shoe (92 grams) reinforced by a string retinacula, built into the sides and heel of the shoe. The key stress lines of the shoe are reinforced with strong fibres or villi which act as a retinaculum to give integrity to the shoes and support to the moving foot. The Vectran® fibers which are a quarter of the diameter of a human hair are made from knitted liquid-crystal fibres have been spun into filaments (called Flywire). The high-strength threads are pound-for-pound five times stronger than steel and have been used in demanding applications ranging from cushioning Mars Rovers during landings to the cabling system on new airborne wind turbines, puncture-resistant bicycle tires and the world's largest sail on a luxury charter. Each Zoom Victory Spike uses 116 strands of the Vectran fiber Flywire strands to keep an athletes' foot supported at key points, such as the heel and forefoot, and also firmly cradled in the spike's footprint, according to the Nike Innovation Lab site. According to the developers this enables more energy to be transferred directly into forward motion with each stride. The tensile stress resisting Flywires lie between layers of thermoplastic polyurethane film and are anchored from the eye stay down to the centre seams beneath the sock liner. Like bone trabeculae they criss-cross in strategic design to give added strength to the shoe ensuring a close fit to the foot. A cross mesh of Flywires has replaced the traditional heel counter which makes it featherlight. According to the manufacturers this system is as close as applying a spike plate directly to the feet. The Nike’s Zoom Victory Spike will be worn by Kenyan American Bernard Lagat (US) in the 1500-meters. Nike have included the Flywire technology in other shoes including the LunaRacer and Zoom Matumbo distance shoes; the Hyperdunk basketball shoe; the Zoom Court Luna tennis shoe; and the Raketa badminton shoe.