Every competitive cyclist or triathlete knows the critical role aerodynamics play in cycling performance. Reducing aerodynamic drag translates directly into saved watts, higher speeds, and improved race times. Traditionally, wind tunnels have been the gold standard for measuring aerodynamic performance. But while incredibly valuable, wind tunnels primarily provide steady-state data—conditions seldom replicated in real-world cycling.
At FLO Cycling, our commitment to pushing the boundaries of aerodynamic efficiency involves extensive wind tunnel testing, advanced computational fluid dynamics (CFD), and crucially, real-world data collection—over 100,000 data points collected from actual riding conditions. This real-world data reveals critical insights into transient aerodynamics, demonstrating why steady-state tunnel tests alone might not fully capture the realities cyclists face on the road.
Understanding Steady-State vs. Transient Aerodynamics
Steady-state aerodynamics refers to conditions where wind direction and speed remain constant, providing consistent and predictable results. Wind tunnel testing usually occurs under these controlled, steady conditions. This approach offers invaluable baseline data on aerodynamic efficiency and helps engineers identify design improvements.
Transient aerodynamics, however, describes the variable, constantly changing airflow encountered during actual rides. In reality, wind direction, intensity, turbulence, and even cyclist position vary continuously, significantly affecting aerodynamic performance in unpredictable ways.
Why Does Transient Aerodynamics Matter?
Real-world cycling is rarely steady-state. Even minor gusts, roadside obstacles, passing vehicles, or rider movements introduce turbulence, altering aerodynamic behavior dynamically. Thus, equipment optimized purely for steady-state conditions around a single yaw angle might not perform optimally under actual riding scenarios, potentially misleading cyclists regarding real-world performance.
Transient aerodynamic conditions directly influence rider stability, efficiency, and confidence, especially at higher speeds, during technical descents, or when riding in crosswinds. Properly accounting for transient conditions ensures consistent performance across a wide range of real-world scenarios.
Real-World vs. Wind Tunnel: Bridging the Gap
Wind tunnels are undeniably critical to aerodynamic design—allowing engineers to meticulously analyze airflow, refine rim shapes, and validate computational models. However, tunnel conditions typically represent idealized, steady-state environments that may overlook transient effects such as:
- Crosswind gusts
- Rider-induced turbulence
- Natural wind fluctuations
- Dynamic changes in rider position
At FLO Cycling, we appreciate the necessity of wind tunnel and CFD data. Still, we believe integrating real-world data into the aerodynamic design process is indispensable to achieving genuine performance gains.
The FLO Real-World Approach
To overcome the limitations of steady-state testing, we’ve collected over 100,000 data points from real-world riding conditions. Our extensive data collection involved high-precision wind sensors mounted directly on bikes ridden by real cyclists across varied terrains and conditions.
This comprehensive data set reveals how cyclists experience air flow in real-world scenarios, providing us critical insights that help fine-tune our designs beyond what traditional wind tunnel tests alone can offer.
FLO Wheel Models and Real-World Aerodynamics
Using insights from real-world transient aerodynamic testing, we’ve optimized each FLO Cycling wheel model:
FLO 49 AS: Designed for versatility across all riding conditions, the FLO 49 AS rim shape excels at maintaining stable aerodynamic performance even amid rapidly changing wind angles. Its moderate depth balances aerodynamic gains with dynamic stability, ensuring consistent performance in diverse real-world environments.
FLO 64 AS: Ideal for competitive road cycling and triathlons, the FLO 64 AS wheel uses an optimized rim shape informed by transient aerodynamic data. This wheel exhibits exceptional stability and efficiency during typical real-world gusts, minimizing energy lost due to corrective steering or handling instability.
FLO 77 AS: Engineered for maximal speed in controlled events such as time trials or Ironman triathlons, the FLO 77 AS benefits significantly from our real-world aerodynamic approach. Its rim profile ensures stable and predictable performance even at aggressive yaw angles, where transient aerodynamic fluctuations are most pronounced.
FLO G700: Gravel cycling introduces unique transient aerodynamic challenges, from gusty crosswinds on exposed terrain to turbulent airflow from variable rider positions on rough surfaces. The FLO G700’s broader, carefully shaped rim addresses these conditions directly, ensuring stable and efficient aerodynamics no matter how dynamic the riding environment.
Why Real-World Data is Indispensable
Real-world testing offers practical benefits beyond steady-state measurements:
- Better Handling and Stability: Real-world testing helps us design rim shapes that consistently maintain aerodynamic stability, translating into increased rider confidence and fewer wasted watts due to corrective steering.
- Consistent Performance: Wheels designed using real-world data provide more predictable aerodynamic behavior across varied riding conditions, giving riders confidence that their equipment performs reliably no matter the scenario.
- Enhanced Efficiency: Understanding transient aerodynamics means optimizing wheels not only for speed in ideal conditions but also ensuring efficiency across realistic, everyday cycling scenarios, ultimately saving significant energy and watts.
Balancing Steady-State and Transient Insights
It’s important to recognize that wind tunnels and CFD analyses remain crucial in aerodynamic optimization. They offer baseline data, detailed airflow visualizations, and repeatable, controlled environments essential for developing aerodynamic wheels.
However, complementing this steady-state data with extensive real-world data ensures a more comprehensive understanding. At FLO Cycling, this dual approach enables us to refine our algorithms used to develop rim shapes that excel in real-world transient aerodynamic conditions.
Real-World Validation: The Ultimate Test
Ultimately, your cycling equipment needs to perform optimally on the open road, where variables constantly change. Our commitment to extensive real-world data collection helps us design wheels that deliver predictable, efficient, and reliable performance precisely where it matters most: during actual rides, races, and adventures.
We encourage all cyclists—especially competitive riders—to complement their understanding of tunnel data with real-world testing. Testing your wheels in authentic scenarios ensures you experience genuine performance improvements and validates equipment choices. You also get to know your gear and how it feels in different scenarios. Trusting your gear mentally is a huge component of confident cycling and ultimate performance.
Conclusion
Transient aerodynamics is a fundamental consideration for serious cyclists seeking real-world performance. At FLO Cycling, we’ve invested extensively in understanding and applying transient aerodynamic data, designing our wheels to excel not only in controlled environments but in the unpredictable reality of everyday cycling.
By choosing wheels developed with both steady-state and real-world transient aerodynamic data—such as FLO 49 AS, FLO 64 AS, FLO 77 AS, or FLO G700—you’re making an informed choice for consistent, real-world efficiency, speed, and stability. After all, when it comes to cycling performance, real-world results are what truly matter.
Co-founder at FLO Cycling. Jon manages the day to day operations and acts as the lead engineer for all FLO products.