For years, elite alpine ski racers have been dressing like golf balls. Not in the sense that they are spherical, but in the sense that their racing suits have been covered in the same kinds of dimples that cover the surface of a golf ball. Get four or five feet away from a downhill racer (when they are standing still) and you can see the small indents built into the fabric.
The theory behind the dimples is the same for golf balls as it is for skiers; create turbulent airflow that will lessen drag. In the ball’s case less drag means it flies farther through the air toward the pin, and in a straighter line. In a skier’s case, less drag means he or she flies down the hill faster toward the finish line.
But look closely at Bode Miller’s or Lindsey Vonn’s race suits at the Vancouver Winter Olympics and you won’t see the telltale indents. The race suits they and their U.S. Ski team peers are sporting (as well as the Canadian alpine team) are heading in a new direction, trying to be as smooth and slippery as possible as they hurtle down the hill.<!-- more -->
“For years we all worked on figuring out what kinds of different textures could we get on a fabric to produce that turbulent airflow,” says Phil Shettig, head of the racing program for Boulder, CO-based ski clothing maker Spyder. “But all of this was in pursuit of pretty small margins in reducing drag.” (In the mid-‘90s Spyder, which is a privately held, introduced a race suit dubbed the “tripwire” which had 1/8-inch wires running through the arms and legs to generate turbulent air flow faster. The suit generated about 20% less drag than the competition. After complaints from ski teams who couldn’t get their hands on the tripwire it was banned.)
For this Winter Olympics, Spyder developed race suit technology more informed by Formula 1 car racing than golf. With the help of some scientists in Australia, Spyder started looking at the effect of friction on aerodynamic drag. Using a wind tunnel for testing in San Diego running at speeds of 80 to 90 miles per hour, Spyder put U.S. Ski team members and a variety of fabric types into the middle of the windblast. “We really didn’t know if any of this was going to work out,” Shettig says. “It affected everything that we thought about in the suit, how it was put together, yarn diameter, the thickness of the pads. Everything came down to being as slippery as possible.”
In the suit that Miller took home the bronze medal in the downhill on Sunday, Spyder used very specific diameter yarns, and as few seams as possible to create a fabric that is “marble smooth”, as Shettig describes it. For giant slalom and slalom events, Spyder incorporated thinner, smoother padding, worn in a separate layer under the suit.
In the wind tunnel, the new suits reduced drag by 1% to 3%. Over a 100 second downhill race course, all things being equal, that savings would translate to one-half to one second faster time. “Of course, that never happens,” Shettig says. “We know that, we are only looking for hundredths of a second advantage - it’s an incredibly small margin that separates gold from silver.” Or bronze, in Millers’ case, from not standing on the podium at all. (Miller may have had the fastest suit, but he took a slower line toward the bottom of the course than the Swiss racer Didier Defago who ultimately won the race beating Miller by .09 seconds.)
The suit’s advantage may be more apparent in upcoming giant slalom races, where the padding’s thinness and smooth edges, in combination with the slick upper layer of fabric in the suit creates 15% to 18% less drag than Spyder’s previous giant slalom suit – an advantage that could potentially translate to shaving seconds off times in giant slalom races.
As a sponsor of the U.S. and Canadian teams, Spyder has made sure every member of those teams is fitted with the new gear. Mere mortals can get their hands on the new suits for about $700 starting in September. Still, up at the Olympics some members of rival ski teams have tried to get theirs a bit early, including a “Swiss star” who Shettig declined to identify. “He asked for one,” Shettig says. And the response? “Heck no,” Shettig says laughing. “Not a chance! We’re here to help our teams win gold.”