High-tech tweaks to aerodynamics testing turns to speed for cyclists

After 12 dizzying laps of the velodrome's steep-walled wooden track, Annie Foreman-Mackey guided her racing bike to a halt in front of a table covered with electronic gear and stared at a monitor displaying graphs and spreadsheets.

"These are your new numbers," the man behind the table told the 24-year-old Kingston native, a recent addition to the Canadian cycling team who served as alternate for the gold-medal-winning women's pursuit team at last summer's Pan Am Games.

"They're about 4 per cent better, which is enormous. With this position, you're a different rider."

Foreman-Mackey and her teammates have been taking aerodynamic testing out of the wind tunnel and into the real world. At the Mattamy National Cycling Centre in Milton, Ont., (the cycling venue for last summer's Pan American Games), they're fine-tuning their equipment and riding position as they pedal – and the dramatic results are a reminder that relatively simple changes can offer "free speed" to riders at any level.

When you're cycling along a flat road on a calm day, between 70 per cent and 90 per cent of your effort goes into overcoming air resistance – a statistic that goes a long way toward explaining the sport's obsession with tight-fitting spandex. But clothing is just the start: Everything from the position of your water bottle to the angle of your back affects how easily you slice through the air.

Elite cyclists have long tried to fine-tune their aerodynamics using wind tunnels such as the one operated by the National Research Council in Ottawa. The problem is that balancing on your bike, motionless, in a wind tunnel doesn't fully reproduce what happens when you're actually pedalling as hard as you can along a road or around a track.

That has changed thanks to a high-tech system developed by Montreal-based Alphamantis Technologies. The Alphamantis system, explains Dr. Andy Froncioni, the company's head of aerodynamics and physiology, relies on a sensitive power meter that measures exactly how much force is being applied to the pedals of the bike. By analyzing the relationship between power applied and the speed of the bike, the system can calculate your "drag area" – the same aerodynamic measure you'd get in a wind tunnel.

Working with Mike Patton, a sports physiologist with the Canadian Sport Institute Ontario and the national cycling team, Froncioni's goal in a three-hour testing session with Foreman-Mackey earlier this month was to optimize her riding position.

The first adjustment, carefully administered by the team's full-time bike mechanic, Dan Peters, involved a minuscule nudge forward for the seat and moving the handlebars slightly forward and down. The resulting 4-per-cent reduction in drag area, Froncioni estimated, might be worth close to a second per kilometre; for comparison, the women's four-kilometre pursuit team missed gold by 2.5 seconds at this year's world championships.

"It felt pretty good," Foreman-Mackey said after digesting the results. "The only thing is that it felt like I was sliding forward on my seat."

This is where the art of cycling meets the science of aero testing: The advantages of a new position have to be weighed against the cyclist's comfort, which ultimately affects his or her ability to pedal as hard as possible. For the rest of the afternoon, Foreman-Mackey pedalled around the track again and again as the crew made further tweaks to seat angle, arm position and other variables in search of the perfect compromise.

Alphmantis's testing system was used by eight pro teams that took part in this year's Tour de France, and it's now available to the public at a handful of velodromes in North America, Europe and Australia, including the one in Milton, starting at $699 (U.S.) for a complete testing session.

Of course, there are plenty of ways to start streamlining yourself without any need for testing, such as sticking to tight-fitting clothes and leaning forward rather than sitting straight up.

There are also some less obvious ones, as a recent series of wind-tunnel tests by the bike company Specialized has revealed. Shaving your legs saves about 70 seconds over a 40-kilometre ride, for example; moving your water bottle from the seat post to the front of the frame saves another 25 seconds.

Do these details really matter? That depends on how hard you want to pedal and how close to your limits you plan to push – but air resistance doesn't just affect elite riders. Even at speeds as low as 15 kilometres per hour, the testing system sees measurable changes. "Aero," Froncioni says, "is always 'on.'"