Aerodynamics – Does it Matter?
Much has been written about the importance of aerodynamics on the bike. Tour de France riders spend thousands of dollars and hours of time in wind tunnels seeking the smallest amount of aerodynamic advantage. But many of us probably think that bicycle aerodynamics serves little importance on shorter races like those featured in the Tri-Maine Series.
On May 5 at the Seacoast Time Trial – part of the Maine Time Trial Series – we had a real world demonstration of the importance of aerodynamics on the bike.
Three cyclists each equipped with power meters raced the 13-mile course at a threshold+ effort. Each rider wore a time trial helmet and a standard issue Portland Velo Club skin suit. The course was relatively flat, with a cumulative elevation gain of less than 290 feet.
Rider 1, weighing 172 lbs, rode a Trek carbon road bike with clip-on aero bars with Bontrager Race X Lite wheels and averaged 288 watts for the course.
Rider 2, weighing 160 lbs, rode an entry-level Felt S-32 Triathlon bike with a Mavic wheel set and averaged 286 watts for the course.
Rider 3, weighing 166 lbs, rode a Scott Timetrial frame, full aero, with Zip 404 wheels and averaged 265 watts for the course.
The results were an unbelievable testament to the importance of aerodynamics.
Rider 1 finished the course in 33:00 with an average speed of 23.64 mph.
Rider 2 finished the course in 31:27 with an average speed of 24.80 mph.
Rider 3 finished the course in 31:13 with an average speed of 24.99 mph.
Rider 1, with a standard issue road bike, was clearly the least aerodynamic of the three. Rider 1 and Rider 2 pushed an almost equivalent amount of power (288 watts vs. 286 watts), yet Rider 2 finished quicker by a margin of 1:33. While Rider 1 outweighed Rider 2 by 12 pounds, the effect of gravity is thought to be minimal on a flat course like this, which is substantiated by an analysis of Rider 2 and Rider 3.
Amazingly, Rider 3 rode more quickly than Rider 2, both of whom rode time trial bikes. Rider 3 pushed 20 fewer watts on average than Rider 2, and he weighed approximately 6 lbs more. But Rider 3 – the Rider with the most aerodynamic bike and body position – still finished faster than Rider 2 by 14 seconds! More importantly, Rider 3 took 1:47 from Rider 1 over the 13-mile course.
Triathletes seeking to improve their times on short courses like those featured in the Tri-Maine series would be well advised to evaluate their aerodynamics on the bike. As you can tell in the real world example above, a more aero rider is able to prevail over a rider who produces more power. Faster speed with less effort is the name of the game.
For more information on bicycle aerodynamics and a terrific chart showing the relative cost of each item on an “aero shopping list” with estimated time savings, visit http://damonrinard.com/aero/aerodynamics.htm.
Dr. Thomas Murray, an avid cyclist, is board certified by the American Board of Orthopaedic Surgeons and an active member of the American Academy of Orthopaedic Surgeons and the American Orthopaedic Society for Sports Medicine. He is President of the Maine Society of Orthopaedic Surgeons.
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