In the second article of our Burning for Kona blog series, we would like to discuss the 2016 IRONMAN Hawaii equipment used by the pros and our experience with these. In our last blog, we calculated the CdA value of some athletes. We were only able to make calculations on the basis of the data available to us, therefore all statements are purely theoretical. The value calculated by us is in each case the average value of the athlete over the entire bike course distance of the IRONMAN Hawaii.
Professional triathletes often have the possibility to use aerodynamic tests in a wind tunnel or on a cycle track to determine the aerodynamically optimal material and seating positions. Therefore it is especially interesting to look at their choice of setup. We look forward to the upcoming World Championship and the setups the athletes will use this year.
For Ben Hoffman, we had calculated a very good aerodynamic value of 22.6 aeroPOINTs (CdA 0.226 m2). In 2016, Ben wore an aerodynamic road bike helmet, which was a good compromise between aerodynamics and ventilation in the harsh climatic conditions of Hawaii. The water bottle was attached behind the saddle in a quite horizontal position and did not protrude above the saddle. This avoids additional resistances for the flow, which is advantageous in 4 of 5 cases.
Jordan Rapp used the POC Cerebel aero helmet. This helmet often achieved good results for many of our aeroTESTers with regard to their CdA value. The very good connection between the helmet and Jordan’s upper body is good to see in this picture. For Jordan, we had calculated an aerodynamic value of 26 aeroPOINTs (CdA 0.26 m2). We assume that Jordan could improve his value if he were to sit longer to get a more horizontal back. For this purpose, the pelvis would have to rotate more, which is only possible if the saddle allows for the additional pressure. Also, the frame would need to be long enough.
Lionel Sanders had one of the fastest bike splits at the World Championship on Kona in 2016. He had the XLAB Aero Pouch 300 attached to his rear bottle cage. This was tested by us only once, but of aerodynamic advantage. For an accurate evaluation, we would have to carry out further tests. From our experience, the use of an aero bottle is usually better, compared to the form of a normal water bottle, because it improves the air flow, similar to the tail fin of a boat. The Aero Pouch is in its profile similar to the profile of an aero bottle, but not quite as consistently. Lionel chose a better-ventilated aerodynamic helmet that is again a good compromise between aerodynamics and cooling. The helmet ends up slightly above his shoulders. In all our previous measurements, a complete closure between helmet and upper body resulted in an improved CdA value.
Athlete Pictures: © Herbert Krabel / slowtwitch.com