Serious cyclists in today’s data age already expect a host of ride information—heart rate, cadence, speed, altitude, temperature, and power output. But what about real-time feedback on how much aerodynamic drag you are producing? Time trial riders will now be paying extra attention; a UK-based company, called Body Rocket, is developing just that. It’s a bike-mounted system for measuring your aerodynamic drag and, if successful, their systems could become as common as power metres are today.

Time trial specialists ,such as world champion Tom Dumoulin, are always interested in what is know as “free power”. This essentially means anything that makes you go faster without extra physical effort. No, we’re not talking motors, but we’re talking anything that makes you cut through the air faster; when you’re riding a bike, aerodynamic drag is primarily what is holding you back.

A prototype of the Body Rocket (left)

Measuring drag

During a normal wind tunnel test, aerodynamic drag is measured by gauges between the bike and the floor. These gauges measure the full drag on bike and rider, but cannot take the actual drag on the road into account—in the real world, drag is constantly changing. Therefore, Body Rocket is developing a system of on-bike sensors to measure live aerodynamic drag. These sensors are positioned under the saddle, on the handlebar stem, and at the pedal cranks, and they feed data to a head unit where you (in theory) will be able to constantly adjust your riding position for the lowest drag.

Free Power

As long as you can still pedal efficiently, this could amount to free power. It’s like have a wind tunnel on your bike at all times! A huge amount of the power that you pedal goes into overcoming aerodynamic drag. The Body Rocket team say that, “On a flat road roughly 90% of the forces holding you back come from aerodynamic drag. As you train, and increase your power output, aerodynamics gets even more important. In terms of power, if you’re pedalling at 250 Watts, 218 Watts is used to overcome aerodynamic drag.”

World Time Trial Champion Tom Dumoulin

We can’t go out and buy Body Rocket’s system yet, unfortunately. “With several patents pending and a functional prototype now undergoing testing, the Body Rocket team is currently demonstrating the advantages of real-time measurement to select partners,” say the team. But keep an eye on this company and its system—it could be then next marginal gain of competitive advantage we (well, some of us anyway) are looking for.