Chase Car Doping

Time flies. So it’s been six months since the last post, give or take a few days. After a while, what new is there to say about doping? I suppose I could write about every story that comes along — which would make updating the old book easier — but after a while it just seems like it’s all the same. Different names, different days, pretty much the same story.

Until, that is, one of my English cousins sent me this article. Seems it’s possible to gain an aerodynamic advantage, let’s call it “chase car doping,” from a follow vehicle. And if you think about it a bit, it eventually makes some sense.

After posting on my Facebook page, I got a few responses that pretty much say, “Yeah, we know that. Been done for years. And the UCI generally ignores anything but the most egregious violations.”

What I find interesting is that someone did the research and actually quantified what type of advantage could be gained. As Marcus Woo’s article on BusinessInsider explains:

Using computer simulations, [Bert] Blocken [of Eindhoven University of Technology in the Netherlands] discovered [in 2012] that during a race, the rear cyclist can reduce the aerodynamic drag on the one in front by as much as 2.5 percent. That’s a lot, considering that 90 percent of a cyclist’s total resistance results from drag.

In general, a cyclist feels drag while speeding along. That’s because air gets pushed forward and squeezed into a small region of high pressure, leaving a pocket of low pressure in the wake behind the bicycle. The high-pressure region pushes back on the cyclist while the low-pressure region pulls, creating resistance.

But the simulations showed that a second cyclist close behind would sweep air forward, filling the gap that the first cyclist created. The air pressure behind the first cyclist isn’t as low anymore, so the wake pulls on the first cyclist less, decreasing the aerodynamic drag.

Pretty interesting stuff. Blocken and a graduate student named Yasin Toparlar did some more tests and found:

[I]f a car is within 10 meters (about 33 feet) of the cyclist during a typical time trial that is 50 km (about 31 miles) long, and if they are traveling at a speed of 54 km/h (about 33 mph), then the car would shave 3.9 seconds off the cyclist’s time. If the car were within 5 meters (about 16 feet), the cyclist would save 24.1 seconds.

These numbers only apply for individual time trials, when a car directly follows a lone cyclist. But when the total time difference between winning and losing is often mere seconds, a trailing car could offer riders a big advantage. “With this information,” Blocken said, “you could influence the outcome of the race.”

Now, if everyone is doing this, it’s not much of an advantage. And truth be told, most time trials aren’t in a straight line, so the effect won’t be as strong. Still, it’s food for thought.

Makes you wonder, as the article concludes, just how much aerodynamic assistance does a breakaway or a lone rider get from the motorcycles that zip along with race officials and cameramen. Might be time for some new rules about chase cars, motorcycles and other support vehicles during pro cycling races.