Aerodynamic Rider Positioning
28th May 2023
This past February we traveled to the Silverstone Wind Tunnel in the United Kingdom to see the effect of hand-position changes on the gravel bike. With Unbound just around the corner, we wanted to share how much someone could potentially save during the grueling 200-mile gravel epic. While there are plenty of ways to optimize your setup on your bike, from tire selection to hydration packs to helmets, rider position is the single greatest contributor towards drag and generally the most important. Even with these simple tweaks, the results and time savings were staggering.
Part of any good aero test is simplicity and repeatability, so for this exercise we limited our runs to 4 common riding positions: Hoods, Drops, “Aero Hoods”, and Puppy Paws*.
The Hoods position was the Baseline run and is the position that most gravel racers will use for the majority of the day. It is comfortable, stable, and safe. It is also one of the slowest.
*Data based on results from our test rider in the Silverstone Sports Engineering Hub wind tunnel. Tests were run at 40kph and a yaw of 6 degrees. Differences in Watts and Time savings between positions were calculated using Bramble CFD software. Your results may vary.
The second position tested was the Drops. While most modern riders coupled with modern frame geometries eschew long periods of time spent in the Drops, it is faster than the Hoods. In our test case, almost 17 watts faster.
Third was a new position you see in professional cycling we call “Aero Hoods”. This where riders hold the hoods with their hands, bend their elbows to 90 degrees, and make their forearms parallel to the ground. This gets the lower back into a similar position to a time-trial bike. If you have seen pro-level riders tilt their Hoods inward, it is likely due to making this position more comfortable and sustainable. It is also reasonably safe as your hands are close to the brakes. Better yet? It saved 56 watts over the baseline Hoods position.
Lastly, we tested the UCI-banned Puppy Paws. While it isn’t banned in gravel races like Unbound, it is the most unstable and even slightly dangerous when used in a pack or by yourself. However, this risk comes with an astounding 74 watts savings over the normal position! Please just use with caution if you do.
So what does this all mean? For our test subject, at a 200mile race like Unbound the savings over the Baseline would be 8min, 30min and 38min, respectively. While these are large time savings, no one is going to be able to ride 200miles in a Puppy Paws position, so the full 38 min would not be realistic.
The question becomes how much could you save by occasionally adopting the 3 other positions? A lot. Let’s assume you ride on the hoods for 70% of the race, the Drops for 15%, “Aero Hoods” for 10%, and Puppy Paws for 5%. You would save over 6 minutes versus just the hoods.
Another way to look at savings would be if you were able to spend just 10% more of the race in “Aero Hoods” than you normally do, you could save 3 min alone.
The caveat here is that some people will benefit more from these changes than others, and that speed will affect the watt/time savings as well. However, a common misconception is that aero benefits extend only to the fastest riders….this simply isn’t true. In most cases there will be a greater overall time savings for slower riders than the faster riders! In a race like Unbound Gravel over the 200 miles, you can easily save minutes just by switching up your hand positions. As a bonus, your back, neck, and hands will likely also thank you for the variety.
So when in doubt, just ride the drops. Or Aero Hoods.