Body Rocket, a start-up that manufactures drag measurement systems for time trials and triathlons, has announced details of a prototype road bike compatible system designed to assist sponsors of the Olympic Triathlons in Paris. 

Sensor arrays, consisting of force (force), air pressure, wind speed, acceleration, inclination, and weight, were previously reserved for bikes designed to fight clocks. Of these bikes, the sensor can only be installed on a handful of models.

Why Switch to Road Bikes"It looks like it has always been on the cards for the brand, but it has worked closely with Iron Man world champion Christian Blummenfeld, who has not focused on road bikes, drafting legal triathlons. Now, in the build-up to the Olympics, where he is looking to take the gold medal, it is expected that a well-pre-fitted setup to his huge promotion will give him a competitive edge and give him time to optimize his position and setup.

Aviation tests are mainly conducted in wind tunnels. Parameters are strictly controlled, but in general wind tunnel time is only a fraction of the time spent on training. The body rocket system aims to replicate the data generated by wind tunnel tests in the real world. 

To achieve this, the road bike is fitted with a new updated airspeed sensor that is mounted under the front computer, similar to the nose cone of an aircraft or the bulbous bow of a cargo ship. 

Behind this is a custom-made stem, which contains all the sensors previously housed in a separate stand-alone unit, usually at the base of the TT bar extension. 

At the top of the integrated seat mast there are further sensors that work in parallel with the stem to measure the rider's weight; this seems to have to be measured rather than estimated as it can fluctuate throughout the race due to hydration levels and perspiration. 

Finally, a pair of pedal sensors are added drag-in, all of which are fed back to the relay unit attached to the bottle cage, and real-time CdA data is sent to the Garmin head unit. 

It's hard to fully understand what each sensor does without going into the full drag coefficient formula, but according to Eric DeGolier, founder of Body Rocket, "Each sensor measures horizontal and vertical forces, and the sensors on the saddle and handlebars also measure pitching and rolling moments, and the system is a good fit." As well as measuring drag (the sum of the horizontal forces of each sensor), it can track the rider's position on the bike.

At this time, it is unclear how much aero penalty these additional sensors will add.

While real-time measurement of drag is certainly beneficial to professional athletes, it may not be useful unless it is accurate. The system mounted on the BMC Time Trial bike was tested along with the wind tunnel by making the same setup changes. 

According to brand data, the maximum deviation from the wind tunnel is 2.7% and the average variation is 0.7%. This is set in a time trial bike, but if the system is virtually the same, it provides an opportunity for real real-world aerotest comparable to a wind tunnel