The Next Innovation in Consumer Aero Data Capture
With a constant battle to increase our aerodynamic efficiency on the bike. Riders are flocking towards the latest tech to capture those marginal gains. One of those major technological milestones in consumer technology are devices that allow us to measure our own aerodynamic performance without renting time in a wind tunnel.
Aerodynamic efficiency is commonly abbreviated to CdA - which stands for your coefficient of drag multiplied by your frontal surface area pushing through the air.
The measurement of Watts per CdA on the bike is a good indication of how quick a rider can ride. The larger the number, the faster you can go. There are two ways to ride faster, the first to to reduce your CdA, the second is to output more power.
For example:
- If a rider was putting out 800W at a consistent 0.25CdA , The Watts per CdA value is 3200W/CdA.
- The rider can improve this value by increasing their power output to 833W while maintaining 0.25CdA, which is 3333W/CdA.
- Or, by reducing their drag down to 0.24CdA while maintaining 800W, which is 3333W/CdA
Technology to measure a riders CdA in real time is next wave of aero tech for the consumer. The most notable publicly available device that measures CdA in real time is the Notio Konnect. The device mounts to the front of the bike in open air. Built in sensors measure the windspeed, temperature, dew point, humidity, etc and compares the data to your travelling speed and input power. Data is streamed to a Garmin or mobile device to determine the aerodynamic force pushing back against your frontal surface area.
Researches PEETERS, GARIMELLA and VERWULGEN from the Department Product Development at the University of Antwerp in Belgium have taken the idea of measuring your aerodynamic efficiency to the next level.
Outlined in their research article published in December 2020, the trio developed a indoor training rig to measure the riders frontal area. This data is used to calculate how much resistance to add to the smart trainer. The more aero you ride, the easier it becomes.
“Wind tunnel tests, computer aided design (CAD) models and projected frontal area calculations are most used to estimate the aerodynamic efficiency of a cyclist. Once the optimal aerodynamic position is defined using one of the above-mentioned methods, cyclists lack feedback on the quality of retaining that optimal pose during training or races.”
As indoor cycling technology currently stands, riders generally set their bikes up identically to how they would ride outdoors. Although this is good for keeping ergonomics and equipment consistent, I believe riders could eek more power and efficiency from a variation of the bike fit that is less aero, but achieves greater power thresholds or FTP (functional power threshold). As far as I know, I haven’t heard of anyone developing a bike fit method to achieve maximum FTP while completely disregarding aero.
“Indoor cycling apps (e.g. Zwift, Zwift Inc) provide realistic environments to simulate real-life cycling experiences by adapting the resistance for e.g. climbing and riding in a peloton. However, the influence of the posture and movement of the cyclist is not included in estimating the imposed resistance, causing that the effect of the biomechanical movement and the aerodynamic drag is neglected.”
Where I see this technology coming mainstream, is the ability to consistently fine tune your body position during a riders indoor training. The system sends vibrations to alert the rider when they are not in an optimal aero position. Adopting an aero body position can often be a struggle. The body doesn’t quickly adjust to extreme aero positions, but overtime it is possible to train yourself into. This new technology makes the concept of racing through the game environment closer to a real world simulation.
“This study demonstrates that the indoor training bike can be used to help cyclists to try and compare several poses during cycling on a smart trainer and to feel the real-life effect of change in resistance for each pose.”
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