RPM Sports » Wind Tunnel Testing with John Cobb of Cobb Cycling

Dec 03 2009

Wind Tunnel Testing with John Cobb of Cobb Cycling

RPM Sports went out to Aggieland’s and spent two days with the Aerodynamic Specialist John Cobb of Cobb Cycling. It was quite an aggie-windtunnel1 experience in its own just being in the wind tunnel! We tested wheels from a Reynolds wheel with a 28mm rim, to a Hed 3, to a Zipp 1080. The results were shocking to all of us, but I cannot say what happened. We also tested a line of different bikes, but the majority of the riders had P4’s, so there was not too much comparison. I will say that the Cervelo P4 is a very fast bike, depending on who is driving the pedals. Even the skin suit was a huge factor in preventing drag, the smallest details, like the stitching and the material of the suit could create more drag.

Working in Tunnel When I first asked John to join him in his extensive testing, he told me to come ready to work. I didn’t think it was going to be too hard, boy was I wrong…Waking up every day at 6am and working from 7-4 straight with very little lunch time breaks; “Time is Money!” Each test would last about 5 minutes, moving the rider from 0 yaw angle to 20 yaw angle. This way you can get data from more angles. After each test run you have to look at the data and analyze what to do next to help the rider get more aerodynamic. It’s expensive to go there so you have to put on the thinking cap and gather the most data you can.

In the tunnel, John put riders in all types of positions looking for more ways to cheat the wind. Some of them look strange and some of them are not really rideable, but in the end John gets the riders going pretty fast. When doing the testing, most people like to run the smoke because it looks cool on video, but John was running the smoke over the riders to help see where the air goes. Smoke does not give you any test numbers but it helps you see things and look for a new direction in testing. The surface of the riders skin suit really effects airflow and small things like hand positions can reduce the drag to help with the race against the clock.

It was a great learning experience for me (Ronnie Strange) and the Intern (Tyler Sutton). The testing in the tunnel is hard work but that is how solid new ideas get started. Thanks again John Cobb and all of his riders for letting me and Tyler help out and observe. Truly an unforgettable two days. Please check out the video here of the smoke flowing over the rider when in the tunnel.