In Airo 101 Part I, we laid the foundation for aerodynamics in cycling. We introduced the golden rule of air resistance: the CdA value. Position, posture, and material together determine how much energy you lose to the air around you.
In Airo 101 II , we delve deeper into the subject and zoom in on the influence of clothing on aerodynamics. Because aerodynamics isn't just about how you sit on the bike, but also about what you wear. Or rather: every fiber of your clothing. Especially at speeds between 35 and 45 km/h, where clothing can account for 30 to 40% of your total air resistance, a smart fabric choice can make the difference between just barely dropping out or riding away. Read this article to learn why this is so, what to look out for, and how we at Airoman.cc leverage the laws of aerodynamics for clothing.
Airflow and resistance: how clothing makes the difference
A quick recap from Airo 101: the way air moves around objects determines their aerodynamics. Two types of airflow are important: laminar and turbulent. Laminar flow moves smoothly and evenly over a surface, with minimal friction and therefore low air resistance. When this flow transitions into turbulent flow—a chaotic pattern with many fluctuations—air resistance increases significantly (White, 2024). The point at which airflow changes from laminar to turbulent is called the transition, and that's where gains can be made.
To achieve an aerodynamic advantage, it's therefore essential to maximize laminar airflow and shift the transition point. Cleverly chosen materials and structures can influence this transition. Contrary to popular belief, this doesn't mean clothing should be as smooth as possible. Fabrics with ribbed or textured surfaces can actually positively influence airflow by better managing the transition from laminar to controlled turbulent flow (Defraeye et al., 2011). Smooth textiles lead to faster detachment of the airflow, which creates larger "weak zones" and thus more drag.
However, one fabric is not the same as another and has a different effect on different parts of the body. Therefore, fabric selection must be tailored to the specific part of the body. Around the upper body (shoulders, upper arms), fabrics are needed that prevent premature airflow detachment, as this part of the body is the first to come into contact with airflows. Here, structured materials (such as ribbed or patterned fabrics) can help create controlled turbulence in the airflow. For areas with less air resistance (such as the torso), smooth textiles may be sufficient. Also, don't forget the impact of stretch and compression: they ensure a snug fit, essential for minimizing air bubbles and wrinkles, which cause drag (Defraeye et al., 2011).
Different materials in the wind tunnel
Wind tunnel research shows that small differences in fabric have a direct impact on aerodynamic efficiency. For example, minimal adjustments to clothing have been shown to make a difference in drag force of up to 10%, depending on speed and surface texture (Crouch et al., 2017). In some situations, aero clothing can even do more for your CdA than a perfect cycling position without it. Clothing is therefore not an afterthought; it's a key factor.
And the best part: that difference isn't just theoretical. At speeds of 45 km/h, a well-tested aero suit can save up to 10 to 15 watts compared to a standard cycling jersey and bib shorts. Just calculate it over a five-hour race—that's not marginal, that's game-changing.
Inside the lines: aerodynamics and the UCI rules
The UCI hasn't lost sight of the benefits of aero clothing. Since 2019, the manual has included clear rules to limit aerodynamic advantages. For example, socks must not extend beyond the mid-calf. And fabrics must not deform to gain an aerodynamic advantage. The fabric's structure must remain the same when not in use, so no clever folds or stiff shapes.
Moreover, there's a limit: a maximum of 1 millimeter of texture or relief is permitted. This means that subtly ribbed sleeves or panels (like those found on time trial suits) are legal, but anything beyond that is out of the question. The rules are strict, but that essentially says one thing: aero works. So it's crucial to make the smartest choices within those guidelines.
Airoman x laminar air flow
The Airoman name already gives it away, but aerodynamics are central to our products. From socks to base layers, every product is designed to channel air past the body as efficiently as possible, within UCI regulations, of course.
At Airoman.cc, we offer several types of socks, with the Airo Evo offering the greatest aerodynamic advantage. The Airo 'Signature' Aero Socks feature a smooth fabric with a slight ribbing, keeping the airflow laminar for longer. With the Airo 'Evo Aero Socks, we take things a step further. These socks utilize smooth, air-flow-conducting materials in strategic zones to optimally guide airflow around the ankle and lower leg.
Our latest innovation is the Airo 'Evo' – Aero Baselayer . Because many cycling jerseys don't use aerodynamic ribbed fabric, valuable structure is lost. The baselayer restores this: by allowing the ribbed effect to work from the inside out, it optimizes airflow around the upper body. And that's precisely the part of the body that cuts through air first, thus providing the greatest aerodynamic advantage.
In short, do you really want to get faster without pedaling harder? Then don't just look at your posture or your bike, but also at what you wear. Because with the right clothing, you'll get every watt and leave nothing behind.
In the next installment of Aero 101, we'll delve deeper into the aerodynamic effects of riding position and material choice that influence CdA. Stay tuned to our Instagram and blog. We'll help you get faster, ride after ride.
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