Heads Are Not Aero

Triathlete on the bike portion of an Ironman
July 17, 2020

Dave Sheanin


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If you’re taking your aero advice from random social media posts or perhaps worse, the forum of a certain triathlon-related website, pay attention to what follows!  Jesse Frank, Human Performance Engineer at the Specialized Win Tunnel, dropped some knowledge on D3 based on the research and experiences in the tunnel.  Some top take-aways:

Where Should I Put My Bottles?

If your bike has integrated hydration storage—a bladder in the frame, nose cone, or behind the seat tube as on the new Specialized Shiv—that’s going to be the most aero position for your drink of choice by far.  If you need to carry bottles, the most aero spot is out of the wind, behind your butt.  However, a rear carrier is not likely the best choice for bottle placement if you’re only running one bottle because the aero penalty for sitting up regularly to reach back for that bottle is significant—enough to wipe out the advantage of the placement. 

Instead, the first place you should put a bottle is between your arms on the aerobar extensions.  For some setups (but not all—a lot of questions get an “it depends” answer from Jesse when it comes to “what’s the best” kinds of questions) having a bottle between your arms is actually faster than not having anything in that space.  But regardless of aero, the biggest benefit to this placement is the easy access and limited need to break out of aero position to access it. 

If you’re running two or three bottles, place one between your arms and the other(s) on a carrier behind your seat (out of the wind).  Drink from the bottle up front and when it’s empty, swap it with a rear bottle.

The worst place for bottles from an aero perspective is on the frame.  The wind isn’t kind to “vertical cylinders”.  If you need to put a bottle on the frame, the downtube is a better spot than the seat tube (it’s less vertical on the downtube).  Aero bottles do make a difference if you need to put a bottle on the frame, but it’s harder to swap an aero bottle with other bottles elsewhere on your bike.

How Fast Do I Have to be Riding for Aero Position to Matter?

As long as you’re moving above about 12-14 mph, you should be in aero position.  A lot of triathletes will come out of aero at higher speeds—particularly as they begin to climb a hill.  Stay aero even if you’re not going super-fast!  Obviously, the faster you’re going, the more aero matters, but even riders who think of themselves as “slow” will benefit from staying down on those aerobars!

Are Disc Wheels Always Faster?

If you have access to a disc, always use it when you’re racing on a flat or slightly rolling course.  (There are obvious considerations for windy courses and individual rider comfort controlling the bike.)  On courses with big climbs, a deep-profile wheel might be a better choice.  (Another “it depends”.)  Most discs carry a weight penalty over a deep section wheel—that can make a difference on the climbs.

How Should My Aerohelmet Integrate into my Bike Fit?

If your aerohelmet has a tail, it should lay flat on your back with no (or minimal) gap.  Part of the aero position is your bike fit and part of it is the way you train yourself to hold position.  (Actually, a great fitter will take everything into account—it doesn’t matter how aero your setup is if you can’t hold the position!).  Limit or avoid looking down at your Garmin, lifting your head up, or turning side to side (except as needed for safety).  The more the tail of your helmet is in the wind (not laying flat on your back), the less aero your aerohelmet becomes!

Are Helmets with Integrated Visors Faster?

They certainly look pretty cool, but those visors are only faster than wearing glasses (or nothing at all—not recommended) if they cover your ears.  A number of “road aero” helmets have visors that simply replace sunglasses but don’t wrap around the sides of your head.  If your ears are exposed to the wind, there’s not an advantage to the visor setup.  Perhaps the best quote of the entire discussion was “heads are not aero”.  Aerohelmets with wrap-around visors that cover your ears are faster—the Giro Aerohead is a good example.

What Is Something That Jesse Sees Triathletes Doing That Makes Him Shake His Head…?

Wearing loose-fitting clothing on an aero bike will negate all the advantages, and then some, of fancy and expensive equipment and fit.  Jesse estimates that even something as simple as a wind-breaker worn on a cool day, could easily cost 4 minutes in an Oly and 15 minutes over an Ironman-distance race!

An example of the difference equipment can make: With his access to the Win Tunnel, Jesse tested himself on the setup he rode for his first Ironman race.  He had a decent tri-bike with a good fit, an aero-helmet and a tri suit in that race—all good choices.  Then he re-tested on a new bike (but held the fit constant), a textured speed-suit, and a new-technology aero helmet to see the difference.  It was 8 minutes.  Jesse had missed out on a Kona slot by 8:40 that year.  He’s a great runner—I think if he had been able to see his competition, he would have run up to that slot!

How About the Advantage of Shaving Down?

On the bike, depending on how hairy you naturally are, shaving legs generally results in a bit more than a one-minute savings over 40k.  Want to squeeze out every possible advantage?  Shave your arms for another 12 seconds.  Facial hair doesn’t make an appreciable difference.  As noted above, you’re already in the “heads are not aero” realm anyhow.

What Should I Do With My Hair?

If you have hair that’s long enough to flow out of the back of your helmet, leaving it in a ponytail should be your last choice.  Braids test fast in the tunnel, but even faster is putting your hair in a bun that tucks under the tail of your helmet.


Look for part two of this article in coming months.  I’ll share more of our conversation and a tip about aero position that anyone can take advantage of—without spending money on new equipment or a professional bike fit.

A quick personal note: In addition to coaching D3 athletes, I’ve coached the University of Colorado Triathlon team for 10 seasons—first with Coach Mike and now with Coach Brad.  I’m sure both of them will agree with me when I say the greatest reward of coaching collegiate club athletes is not the national championships (of which we have 8 in the past 11 years) but rather seeing our athletes graduate and go on to really great things—on and off the race course.  Conducting an interview with an emerging leader in aerodynamic research and application who also happens to be a former athlete I coached for six years through his undergraduate and graduate education—whom I got to see (and hopefully help) grow from a teenager full of potential to a mature (he’d probably argue with me on that one) professional, respected in his industry—is a true honor that warms my heart.

Want to connect with Jesse directly?  Slip into his DMs, as the kids say...@jfrank32

Coach Dave Sheanin has an overarching belief that becoming “triathlon literate” is key to meeting your goals. Triathlon is indeed a lifestyle and like the other important areas of your life, knowledge is power. I encourage you to explore the nuances of the sport, be open to new ideas and ask questions – of yourself, of fellow swimmers, cyclists and runners, and of your coach. Whether you’re training to win or new to the sport, the most accomplished athletes are those who are open to coaching, eager to take on new challenges, and are committed to continuous improvement!

Dave is a USA Triathlon and Training Peaks Certified Coach.

Coach Dave Sheanin is an advocate for aligning triathletes with their race goals. He believes that becoming “triathlon literate” is key to meeting your goals. Triathlon is indeed a lifestyle and like the other important areas of your life, knowledge is power. He encourages you to explore the nuances of the sport, be open to new ideas and ask questions – of yourself, of fellow swimmers, cyclists and runners, and of your coach.  

Coach Dave is a USA Triathlon and Training Peaks Certified Coach.  Coach Dave was honored by USA Triathlon with the Community Impact Award.

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