Streamlined to success
In triathlon, every second counts. While iron training lays the groundwork, an often underestimated factor can tip the scales: aerodynamics. Anyone who understands and uses the fight against the wind saves valuable grains and gains important minutes, especially over long distances. In this article, we dive deep into the world of aerodynamics and show you how to optimize yourself and your material into a streamlined weapon.
Understanding the basis: frontal area and the decisive CDA value
When we talk about aerodynamics, two key figures are of central importance: the frontal area (A) and the flow resistance coefficient (Cd value).
The role of frontal surface and Cd value:
Die frontal surface (A) Put simply, is the area that athletes and bicycles offer to the wind from the front. The smaller this area, the less air has to be displaced. The Cd value On the other hand, describes the “wind slipperiness” of a shape — i.e. how well the air is directed around an object. An aerodynamically shaped drop has a very low Cd value, a flat plate a very high one.
Influence on aerodynamics:
Both values multiplied result in CDA value (cdA). This value is the ultimate measure of aerodynamic resistance. A lower CDA value means that athletes need to use less power (watts) at the same speed or are faster at the same performance.
Optimization for less air resistance:
The goal is therefore clear: to minimize the CDA value. This is achieved by reducing the frontal area (e.g. through a more compact sitting position) and/or improving the Cd value (e.g. through aerodynamically shaped frames and components).
Reduce frontal area:
The most effective measures for reducing the frontal area involve posture: a lower upper body, narrower arms and a retracted head. But narrower handlebars or aerodynamically positioned water bottles can also help.
Lower CDA value — best strategies:
The best strategies include a combination of optimised sitting position (more on that later), the choice of aerodynamic components (helmet, wheels, suit) and a frame with low air resistance.
Aerodynamics: Why it is so crucial in triathlon
The importance of aerodynamics in cycling, particularly in triathlon, can hardly be overstated.
How aerodynamics improve speed:
Air resistance increases exponentially with speed. This means that at higher speeds, a disproportionately large portion of the energy expended is used to overcome air resistance. Improved aerodynamics reduce this resistance so that more of the power you provide is converted directly into propulsion — you get faster.
Comparison: triathlon bike vs. road bike:
Triathlon bikes are designed from the ground up for minimal air friction. Their frame geometry enables a deeper, more extended sitting position, and the tube profiles are often aerodynamically optimized (e.g. drop or comb-tail shapes). Road bikes, even aero racing bikes, are often a compromise in terms of handling, weight and UCI regulations, while triathlon bikes (often not UCI regulated) are more radically designed for streamedness.
The importance of aerodynamics:
Good aerodynamics make an enormous difference, especially on the mostly flat and fast triathlon cycle routes, where athletes often fight alone against the wind for hours on end. Several minutes can be saved.
Effects on energy consumption:
Less air resistance means less energy required for the same speed. This saved energy is then available for the rest of the race, in particular for the final marathon. Athletes are therefore fresher off the bike or can complete the bike split with higher performance.
Optimize aerodynamics — What to consider?
Optimization is a complete package. It starts with the choice of frame, through components such as wheels and helmets to clothing and, above all, the sitting position of the athletes. The individuality of the athlete must always be taken into account - what are the anamtomic conditions, how does a sitting position change comfort, etc.
Aero optimization triathlon bike: useful upgrades and components
The triathlon bike itself offers numerous starting points for aerodynamic improvements.
How do I optimize the aerodynamics of my triathlon bike?
Optimization starts with an inventory: Which components are already aerodynamic? Where are there “air brakes” such as protruding cables or inconveniently placed bottles? All loose parts that can potentially flutter and cause air turbulence should be fixed - insulation tape can be used for this purpose.
Useful upgrades:
Not every expensive upgrade provides the same aerodynamic advantage. The most effective measures include:
- Aerodynamic wheels: High-profile rims reduce air resistance and can even produce a slight “sailing effect” under certain wind conditions.
- Aero helmet: One of the most cost-effective upgrades. The athlete's head is one of the first points of contact with the wind. However, it should be individually tested which type of aero helmet makes sense in a single barrel (long “nose”, short “nose”, etc.).
- Integrated hydration systems and storage solutions: Aerodynamically shaped hydration systems (integrated between arms or in the frame) and bento boxes/storage boxes that fit seamlessly into the frame design are better than traditional round bottles and patch pockets. Gels/bars attached loosely to the top tube are also very unfavorable in terms of aerodynamics.
- Aero driver: Enables the basic aero sitting position The right choice and adjustment (width, height, angle of the extensions) is crucial.
- Tight-fitting triathlon clothing: Fluttering clothing acts like a brake screen. Special aero suits with textured surfaces can further reduce air resistance.
- Improve aero efficiency: It is about looking at the entire “Athlete:In-Rad” system. A tidy look with neatly laid cables and minimized attachments is often a good start.
The power of shape: How the shape of the frame influences aerodynamics
The bike frame is the foundation of the aerodynamic setup. Its shape plays a decisive role.
Frame shape and aerodynamics — What you need to know:
Modern triathlon frames often use tubular profiles inspired by aviation, such as teardrop shapes or so-called “comb tail” profiles (drop shapes flattened at the back). These profiles help to guide airflow along the frame in a laminar manner (with minimal turbulence) and reduce air resistance.
Importance of frame shape:
Since the frame represents a large surface area, its shape has a significant effect on the overall air resistance of the system. The integration of brakes, cables and storage compartments into the frame design also contributes to overall aerodynamic performance.
Frame shape and air resistance:
The difference between a traditional round tube profile and a sophisticated aero profile can be measured in a wind tunnel and on the road. Special frame shapes offer significant aerodynamic advantages.
Practical tips: How to aerodynamically optimize your triathlon bike
In addition to buying new components, there are many ways to aerodynamically improve the existing material.
The best tips for aero optimization:
- Cable management: Route cables and cables as closely and internally as possible. Every exposed train creates unnecessary air resistance. Use cable ties or heat-shrinkable tubing to keep things tidy.
- Bottle positioning: A single water bottle horizontally between the aero handlebar extensions (BTA mount = between-the-arms) or an aerodynamically shaped bottle deep on the down tube is often better than two bottles on conventional holders. Test what works for you and remains accessible.
- Optimize storage: Use integrated top tube pockets or aero boxes behind the saddle for gels, tools and spare tubes. Avoid loose pockets
- Fine-tune handlebar setup: Make sure the base bar is clean Remove any unnecessary spacers over the stem (provided the position allows it and it is safe).
- Remove excess: Any unnecessary attachment (e.g. empty holders, pump holder without pump) should be removed for the competition.
- Which upgrades bring the biggest improvement? The biggest jumps are usually achieved by optimising the sitting position (see below), followed by an aero helmet and aerodynamic wheels. A good aero suit is also an important factor.
- Modification for less air resistance: Even on a racing bike, a significant improvement in aerodynamics can be achieved by installing clip-on aero handlebars and adjusting the saddle position.
The decisive role: The sitting position of the athletes
The most expensive aero material is of little use if the athlete's position on the bike is not optimized. The body is the biggest “wind catcher.”
Importance of sitting position:
Studies show that the body of athletes is responsible for around 70-80% of the total air resistance. An aerodynamic sitting position is therefore the biggest lever for reducing the CDA value.
Sitting position for more aerodynamics:
The aim is to minimize the frontal area. This includes a back that is as flat as possible, a head held low (ideally as an extension of the spine), arms brought together closely on the extensions and narrow knees when pedaling.
Influence of sitting position:
An optimized position not only reduces air resistance, but can also influence biomechanics in such a way that the muscles required for the run are spared.
Find an optimal sitting position:
The “perfect” aero position is highly individual and depends on factors such as flexibility, core stability and competition distance. Professional bike fitting is essential here to find a position that is both fast and durable over the course of the race. In addition, tests in the field (e.g. on the bike track or even on a fixed track outside) or wind tunnel tests can help to compare different seating positions and materials. There should always be a focus on comfort in the position, as the best aero position for long-distance events is worthless if it can only be driven for a very short period of time.
The ultimate discipline: optimising aeroposition
Knowing a good theoretical aero position is one thing, being able to maintain it efficiently and for hours in competition is another.
Optimize aeroposition:
This is a continuous process. Start with a good basic bike fitter setting. Train regularly in this position, both on the roller and outdoors, to adjust musculature and coordination. Significant amounts of aero position should be completed early in preparation to ensure that it can be driven comfortably.
Factors for the perfect aero position:
- Head position: Try to keep your head as low and in line with your back as possible without interfering with vision or breathing. A “shrug” (slightly raise and relax shoulders) can help close the gap between head and shoulders.
- Arm and hand position: The forearms should be parallel and as close together as possible on the pads. The hands grasp the extensions in a relaxed way.
- Hip angle: An open hip angle is important for developing strength and making the transition to running. To ensure this, shorter cranks can be used. As a result, the lift height decreases during the pedal revolution and the hip remains open while pedaling.
- Trunk stability: Strong core muscles are essential to be able to keep an aggressive position stable without tilting sideways or sagging in your back.
- Tips for the perfect aero position: Do video analyses of yourself on the roll (from the front and from the side). Watch professionals. And above all: slowly get your body used to changes. Radical changes often lead to symptoms.
The art of balance: reconciling comfort and aerodynamics
The fastest position on paper is of no use if it causes pain or cannot be held over the entire distance.
Combining comfort and aerodynamics:
The goal is not the most extreme, but the most effective position. This is an individual balance of maximum wind flow and the ability to maintain this position comfortably and efficiently for hours.
What is more important?
For most triathletes, particularly on medium and long distances, a sustainable position that is aerodynamically very good but not exhausted to the extreme is often the better choice. If the position is too aggressive, the muscles cramp up, performance decreases, and the subsequent run becomes torment.
Find the ideal balance:
This requires patience, a willingness to experiment and a good body awareness. Regular training in the aero position, adjustments to the setup (e.g. saddle, handlebar height, armpad position) and, if necessary, renewed bike fitting help to find this sweet spot.
Balancing and optimizing:
Comfort doesn't mean sitting upright like a candle. It means that joints are not overloaded, there is no numbness, and breathing is not restricted. A good aerodynamic position should be able to be taken in a relaxed manner.
conclusion
Optimizing aerodynamics in triathlon is a complex but rewarding endeavor. It is a combination of the right material, clever adjustments and, above all, a well-trained and individually adapted sitting position. Don't forget that every small improvement can make a big difference overall. Invest time in your setup and position — it will pay off in the hunt for new best times!
Welcome to Enduure
“We founded Enduure to support endurance athletes with scientific training, smart analysis and a strong community. Growing together, achieving top performance and redefining sport — that is our mission.” - Simon & Philip
simon
Simon is a professional triathlon player and starts in the Bundesliga for Team Berlin. He is also a sports scientist and certified sports nutrition consultant.
Philip
Philip is a doctor, DOSB C-trainer in triathlon and starts in triathlon himself as an ambitious amateur at various distances.
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