TURBULENCE

Words by Steven Jones
Photos by Sterling Lorence

Trek World Cup Downhill team follow in the footsteps of Lance Armstrong and enter San Diego’s famous low–speed wind tunnel.

The Trek World Cup downhill team have just conducted extensive testing in the San Diego wind tunnel that is used by the military and major cycle road race teams ahead of the forthcoming World Championships in Australia.

Setting out to establish some hard facts on the varying levels of drag resulting from changes to body position, clothing and bike design the team have gained an invaluable body of information that will be used by both the riders and product managers. It’s very likely that the tests will have an immediate affect on race strategies and might well eventually lead to changes in downhill bike design.

Trek brought the whole shooting match to San Diego, including all the aerodynamic experts and industrial designers to aid Tracy Moseley, Justin Leov and Andrew Neethling and the in–house boffins.
Read the whole feature in the latest issue of Dirt 91, which is available now. But for those of you that can’t wait, here’s a sneak peek of what went on.

Balanced on what is effectively a set of giant kitchen scales Tracy Moseley gets messages relayed through a remote microphone from Doug Cusak, Trek’s senior R&D engineer, on changes to body position. Ahead of her a solid wall of air blows in from a gigantic honeycomb structure.

Able to generate speeds of up to 180mph San Diego’s low speed wind tunnel is used for research in the aerospace industry and also by the world’s leading road race teams. The gigantic circuit, just yards away from San Diego airport, has been visited by countless road riders and time trialists in search of seconds, but all this comes at a vast cost.

From behind the tunnel dips down like a swimming pool and widens toward the bottom corner reaching about 35 feet square before curving ninety degrees to that massive propeller.

One of the three variables involved was the affect of changes to clothing. Here Michael Hammond, senior industrial designer at Trek, prepares one of Moseley’s lids. The team measured different helmets, peaks and goggles as well as clothing and body armour.

Hammond again, this time preparing a Moto GP style back protector for Tracy. The wind tunnel has a team of experts on hand and machinery to make running mods.

Two bikes were used. The first was a standard Team bike and the other a custom made version. Seconds after this bike was put into the tunnel there was a huge surge of energy around the rooms as the boffins discussed the significant results.

Andrew Neethling on the custom bike experiments with changes to body position. Each rider was able to see instantaneously the effect of changes to riding style and hence will help to find the optimum position for certain sections come race day.

Scott Daubert keeps close guard of those priceless figures.

Mission control.

Leov going through changes that could well gain him the vital hundredths. With the top ten on some occasions now only separated by a few seconds the team now has one extra layer of information on hand from which they can plan a race.

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