The QR SRseries: Why Wind Tunnel Testing Matters

Aero road bikes may seem in fashion with their deep tubesets and curvateous, wind-slicing curves that bring the stylings of sports cars to two wheels—but they’re much more than for show. As is the case with the Quintana Roo SRseries aero road bikes, wind tunnel testing has proven them to not only slip through the wind with greater ease than standard road bikes, the SRseries bikes actually tested fastest among several competitors, to become one of the top aero road bikes available today.

But there’s a common misconception, which goes like this: “maybe an aero road bike can provide an advantage to pros—but is the advantage really still there for me? Just how much faster is my aero road bike?” But there’s just one way to know: test. Ronald Regan once said “trust—but verify.” When we developed our SRseries aero road bike range, we did exactly that: tested in the tunnel, to prove it’s not only one of the fastest aero road bikes available today, but also has benefit to every rider—regardless their speed.

Much can be divined from our data-heavy SRseries Wind Tunnel Test, where our SRsix and SRfive bikes came out faster than comparable aero road bikes from Canyon, Cervelo and Specialized.

We wanted to know more, though. What does that mean to us? Quintana Roo  lead engineer Brad DeVaney was able to extrapolate the wattage required to move a traditional round-tubed road bike through the wind, at speeds from 18 to 30 miles per hour, as compared to the SRseries models—the SRfive and SRsix.

The results? Simple confirmation: the SRseries bikes are approximately 16.5 percent more efficient than a traditional round-tubed road bike. With the SRfive or SRsix, you’ll get you from point A to Point B with less effort.

OK, this is an obvious one: make tubesets slide through the air with greater ease, the bike punches a smaller hole through the wind—and you go faster. Pretty simple. A higher speed with less effort—a faster bike is a faster you.

The below chart illustrates the watts (or effort you put through the pedals) required at a given speed.

The lines for the two bikes—a round-tubed road bike and a Quintana Roo SRseries—is linear, but diverges as speed goes up, with the power requirements to attain a given speed rising with increased speed. In short: in order to go faster, you have to work 16.5 percent harder (on average) than you would with an SRfive or SRsix. While the greatest benefit of an aero road bike goes to the fastest riders, the benefit of an aero road bike are instant, regardless your speed. An aero road bike will make you a faster rider, regardless your riding acumen.

“Using a speed of 21 miles per hour as an example, the SRseries is roughly 1.3 miles per hour faster than his traditional road bike,” Devaney says. That may not seem like much on its face but over the course of a long ride, or the critical late moments of a breakaway, it’s enough of a difference to stay away for the win, or get caught by the pack. For a short-course ITU triathlete,  seconds saved in a short-course breakaway mean a quicker entry into T2 then the rest of the pack. And the savings stack up there, to minutes in a longer Ironman 70.3 or full Ironman race.

The benefit of an SRfive or SRsix doesn’t stop with your optimized power output. As one might experience with deep aero wheels, there’s an effect that once you’re “at speed,” —riding comfortably just below your threshold—it’s easier to maintain that speed. Says Quintana Roo product manager Chris Brown of his SRsix: “I find it easier to maintain higher speeds, without just dying in the process.”  

The question then becomes, if wind tunnel designing and testing the SRseries bike to prove it’s  faster than the road bike I’m currently riding (and many top aero road bike competitors), why wouldn’t I take advantage of those benefits? Devaney, a competitive weekend rider in his own right, sums it up nicely.

“I relate it to how long I can hang with the A group,” he says with a laugh, referencing his local weekend group ride, “and knowing which guys in the group that were pissed that this overgrown old guy was in there, breathing their air!” Being part of the fast crew never gets old.