The better part of strategy in professional cycling rests upon the physical principle of drafting. You lock onto another rider’s back wheel, hunch down in his slipstream, pull to within an inch or two of endo-style disaster and—while he hammers on his pedals—cruise effortlessly in his wake. It feels like your ride has sprouted wings, or you’ve been suddenly endowed with superpowers (and not the oh-so-pedestrian blood doping variety).
A simple explanation of drafting can be found at The Exploratorium’s “Science of Cycling”: The bicyclist, as he moves through the air, produces a turbulent wake behind himself. It makes vortices. The vortices make a low pressure area behind the bicyclist and an area of wind that moves along with the bicyclist. If you're following a bicyclist and can move into the wind behind him, you can gain an advantage. The low pressure moves you forward, and the eddies push you forward.
It’s pretty straightforward, yet very cool, science at work. But, in a real Jedi trick of physics, the lead cyclist who’s being drafted also gains an advantage (it’s all there in the article, so be sure to check it out). So, drafting is why sprinters have lead-out trains, grand tours have team time trials and, for the most part, why domestiques have jobs (they pull the team leader). It’s what allows pros to average 25 mph over 2,000 miles, many of which wind through the mountains. It’s a beautiful thing when talented riders draft.
Last week, a cyclist was filmed in Europe blazing down a highway at 55mph. He was—get this—tucked into a big rig’s wake. It’s pretty unbelievable stuff, and not just because he’s not wearing a helmet. This video comes with the usual DON’T TRY THIS AT HOME disclaimer. Seriously, one pothole, or an unexpected braking by the truck, and this guy is a goner:
Not since disgraced doper Jan Ullrich retired from pro racing has there been something this big—or fast—to hitch a ride on. But drafting trucks isn’t all that unusual. One of my brothers, a former college triathlete, used to fly down local back roads at 35 or 40 mph, glued to the bumper of an unsuspecting FedEx or UPS truck.
You don’t have to take our word for it, though. Here are a couple more examples from around the web (though neither is as wild as the first one):
The Discovery Channel’s “Mythbusters” tested the theory themselves. Their test consisted of an unlucky guinea pig strapping on a heart rate monitor, then huffing and puffing away at 20 mph on a hard-tail mountain bike (no easy feat), first unaided and then tucked behind a big rig. By himself, his heart rate averaged 166 BPM, and the tester was quickly worn out. When he latched onto the truck’s bumper, he was easily coasting along behind the truck. So they proved what cyclists have always known: drafting works. Check it out:
As gnarly as these road warriors are, they’ve got nothing on legendary triathlete John Howard, who set the drafting—and bicycle land speed—record of 152.2 mph on Utah's Bonneville Salt Flats in 1985. Talk about superpowers.