Swimming has been grabbing the American headlines so far at the 2008 Beijing Olympics. Now attention begins turning to track and field, where U.S. athletes have grabbed 713 medals all-time, more than the combined total of the next three countries.
Experts say the track in Beijing will be the fastest ever thanks to materials engineering. Tracks used to be made of dirt, clay and even cinders until the 1950s when Tartan synthetic athletic surface was introduced, originally by 3M.
One expert on the development of fast tracks is Mike Garrett, the president and head of R&D at Athletic Polymer Systems of Corona, CA which now owns the Tartan brand. "If the track surface's 'relaxation' time or time it takes to re-orient itself on impact is too fast, it'll seem jarring to the athlete. If it's too slow, it'll feel like running in sand," he says.
The million-dollar Beijing track uses a technology developed by Mondo SpA, which has supplied all Olympic tracks since 1976. Based in Italy, Mondo has a new production site near Beijing that supplied materials used in the Olympics. Tartan had supplied earlier Olympics. The rubber MondoTrack FDX in the National Stadium is extra thin, making for a harder surface and faster times. "The Super X Performance optimally designed geometries allow for the greatest deformation and subsequent energy return with the most consistent response," says a Mondo spokesperson.
The all-natural rubber surface was glued onto asphalt to make the track. The eight-lane track nine lanes on the finishing straight is a clay color. Mondo has improved the track since the Athens Olympics through research at a number of universities, including Harvard. For example, a new backing has a hexagonal shape which is said to help with compression and energy return.
U.S. Olympic athletes qualified this summer at a new field at the University of Oregon that is an example of the new fast tracks. It's a "dual-durometer" construction made of asphalt and stone base, polyurethane (PU) surface and a butyl rubber layer that helps with high return of energy during striding and exceptional shock absorption.
The track surface is finished with embedded ethylene propylene diene monomer granules for advanced traction. Unlike sheet rubber applied to asphalt with glue, PU is chemically bonded to the asphalt. Because PU is poured into place, if offers a seamless surface without tripping hazards.
Another PU advantage, according to Bayer Material Science, is that it can be customized to the local climate and the aims of the coaching staff. A harder surface, for example, could be preferred for sprinting while more cushioning is desirable for long-distance running.