Pillars of Speed, Part 4: Aerodynamics
This is part four of the Pillars of Speed series. You can find the prior installments here:
Aerodynamics
Optimization of frontal surface area and shape to reduce aerodynamic drag.
Reducing aerodynamic drag is the final goal of the fit. I’ve spent hours testing athletes in wind tunnels and velodromes. Making major changes to rider positions to chase a lower drag number requires a delicate balance. I carefully assess the trade-offs, knowing their positions are already optimized for comfort within their biomechanical profile. Before doing something drastic, I ask myself, Can the athlete adapt to this change?
Often, the safe changes or optimization rely on small tweaks of the head and arm position, elbow width, or hand height, which can yield significant aerodynamic gains without compromising comfort or power. Additional factors, such as helmet selection, clothing, and bottle placement, also play critical roles.
Lets look at a real world example that we saw take place with two of the best triathletes in the world at last year’s Ironman World Championships. Kristian Blummenfelt and Gustav Iden showed up to Kona in what could be called “Superman” positions. I view the Norwegian team as a “leave no stone unturned” one. The positions were clearly aero driven and they took the risk hoping to give themselves an advantage over the field.
The positions were short lived and the departure from them is proof that they didn’t check all the boxes of the speed equation: comfort + power + aero. These positions leaned too heavily towards the aero portion of the equation, showing that sometimes the most aero position isn’t the best position for long distance triathlon. They made this change pretty close to the race and perhaps, given more time to adapt, we might see a similar version of this positions again in the future?
As you grow comfortable in your position, how can you can begin to tinker to find additional aerodynamic gains? A position that wasn’t viable a year ago may now be worth a shot because you’ve adapted to the previous setup and are very comfortable and in control in the position. You perhaps can go through the same process again by taking on a more aerodynamic position and allowing your body to adapt. This is why it might seem like athletes are constantly getting bike fits. What they are really doing is trying to find improvements and giving the body a chance to adapt to them. Sometimes they do and other times they’ve found their limits.
How to Get More Aero?
So what makes a more aerodynamic position? The goal is to minimize frontal surface area and streamline your shape to reduce drag. There are many ways to do this, but to validate that a change is actually faster, you’ll want some form of testing or feedback. When this is not an option, you’ll need to at lest make sure your position is comfortable and that you can produce power. From there, you’ll need to just rely on the basics of what traditionally are best aerodynamic practices.
When it comes to your position, the first order of business is lowering your front end to reduce your back angle. Sitting up and exposing your head and chest to the wind is not going to enhance your speed. Another popular option is to lengthen the front end to increase the rider’s reach, stretching out onto the front end. That can also lower your back angle and change the upper-arm angle, theoretically presenting a smaller “cylinder” to the wind. Narrowing of the elbows in another way to minimize frontal surface area.
These are just some basics that are “traditionally” aerodynamic best practices, but the way the wind flows around the body can be a mysterious thing.
Posture
Posture on the bike is where I’ve normally seen the biggest gains. When I’m working with an athlete and they come into the fit studio and have poor bike posture. I can often guide them towards postural improvements that are so drastic that when I show them a video of before and after the position looks dramatically different, yet I made zero changes to the contact points on their bike.
This is the biggest change that I’ve seen in bike fitting over the years. When I mentioned lowering the bars to reduce the back angle, it used to be that you’d lower them as far as the athlete could tolerate without closing down the hip angle. Now, we still want to lower the bars, but do so in a way where the rider can relax into the position vs reaching for their drop.
Here are some tips on how to have good posture on the bike. First, place your elbows on the pads (you can have the point of your elbow off the back of the pad, but I prefer there to be little to no overhang), relaxed neutral wrist and hands with thumbs over the top of shifters (no death grip), and the just relax on the front end in that position…it should feel almost lazy. Your head and spine should be in the neutral position looking at your front tire. From there, just lift your chin, not your head. The opposite of what I just described is what I call a periscope head. Periscope head is what it sounds like. It’s where the rider lifts their entire head and face up into the wind. It’s not only uncomfortable for the neck, it also exposes a big bowling ball shape to the wind. This is also a symptom of when an athletes front end is too low and they are reaching for their drop vs comfortably falling into their position.
In the neutral head/spine position you can still see down the road…I am not advocating for riders to keep their heads down where they cannot see. I encourage riders to float between some periscope head to look way down the road while spending the majority of time in the neutral position. With time and adaptation, you’ll be able to avoid periscope head all together as you become better at lifting your chin to see further down the road.
Another postural technique is the shrug. The shrug narrows and morphs the shape of your upper back and shoulders. It’s not natural and takes practice to hold. Athletes typically won’t be able to maintain a hard shrug the entire race, but will use it as a tool when speeds are high or when an athlete is trying to attack. To perform a shrug, you essentially bring your shoulders toward your ears. You can just stand up and do this. When shrugging in the aero position, some athletes bring their shoulders forward while others can stay more stretched out. An example here would be to look at Gustav Iden, who tends to keep a tighter position, whereas Magnus Ditlev maintains a stretched out position.
Equipment
The other lever for reducing resistive forces is equipment: aero helmets, skinsuits, fast tires, aero wheels, ceramic bearings, and smart bottle setups. All of these can make you faster without an increase in fitness.
What’s “the fastest?” Many companies are making excellent products. In most categories there are several brands where it’s hard to go wrong.
Discussion
I have a theory I want to explore in 2026: I have a hunch that these taller, longer positions are not as aerodynamic as athletes riding lower positions. They might be extra comfortable and produce great power, but some of the setups don’t pass the sniff test for me. I’d love those that have done more testing recently than I have to give their opinions on this because I’ve not had the chance to test them myself.
I believe it’s the case where you’ve had some athletes put in the time to find a position that checks all the boxes and others just followed suit. And, when folks do get the chance to test, are they just testing variants of the same theme from a position standpoint? I could very likely be mistaken, but I find it hard to believe that the positions from the images above are the fastest options for these athletes.
The taller positions do allow athletes to have nice head positions, but I believe this can also be done with a lower position as you see from Rudy Von Berg below.
Several pro athletes who have adopted a more relaxed position have texted me after races: they’re putting out plenty of power yet still getting dropped by the front group or failing to bridge as they have in the past. With advances in technology, athletes are riding really well these days, but I don’t think the relaxed positions are contributing as much, especially if athletes haven’t tested alternatives.
When I look at pro-tour riders, I believe triathletes are capable of these positions and they are more aerodynamic. I don’t see time trialist raising their front ends riding and riding in relaxed positions. In fact, some of the best time trialers have tightened their front ends. Yes, UCI rules limit what they can do, but there’s still some flexibility (Pogačar rode a longer position in 2024 and brought his bars in for 2025). Obviously, Remco doesn’t have to get off the bike and run, but having worked with many pro-tour riders, the same speed equation applies: comfort + power + aero. Pro-tour riders still complain about comfort, but they find positions they can “tolerate” for the duration of the event.
I’ll concede these newer relaxed positions might be more robust for a lot of triathletes, but if you’re focused on aerodynamics, I think we’ll see athletes gravitate back to more steam-lined positions, checking the comfort + power box, and still being able to run their best off the bike.
Summary
Start with a proper fit from an experienced fitter. Once you have a solid baseline, it’s easier to make incremental aerodynamic changes over time as we adapt to each progressive change. We all have our quirks, but orthodox time-trial positions are achievable for most triathletes.
Start the discussion at forum.slowtwitch.com