Wake Interaction: Can a Front Wheel’s Aerodynamic Profile Improve Rear Wheel Performance?

When we discuss aerodynamic performance in cycling, we often isolate individual components—the frame, handlebars, helmet, or wheels. However, cycling aerodynamics is inherently complex, involving intricate interactions between multiple components. Among these interactions, one frequently overlooked phenomenon is how the airflow created by your front wheel influences the aerodynamic performance of your rear wheel.

At FLO Cycling, we have extensively studied the aerodynamic performance of individual wheels and computer modeled wheel, bike, rider systems.

Understanding Wheel Wake Dynamics

The “wake” in aerodynamic terms refers to the region of turbulent air created behind a moving object—in this case, your bicycle’s front wheel. Initially, the air approaching your front wheel is relatively smooth and undisturbed. After passing the front wheel, this airflow becomes turbulent, influenced by the wheel rim, spokes, hub, fork, frame, rider’s legs, crankset, and pedals.

By the time this airflow reaches the rear wheel, it is far from ideal, having lost much of its initial smoothness. Additionally, since approximately 80% of real-world cycling involves yaw angles ranging between -10 and +10 degrees, the airflow doesn’t travel straight from front to rear. Instead, it blends and interacts dynamically, complicating aerodynamic behavior.

The Importance of Yaw Angles and Wake Interaction

Yaw angles describe the angle between the incoming airflow and the bike’s forward direction. Most real-world cycling conditions see yaw angles fluctuating due to environmental conditions, rider movements, and terrain. This variability complicates the aerodynamic interaction between the front and rear wheels, as the rear wheel must manage air that is both turbulent and directionally unpredictable.

Optimizing your wheels for a realistic yaw-angle spectrum and accounting for wake interaction can drastically enhance aerodynamic efficiency—translating into real watt savings and improved riding speeds.

How Wheel Width and Rim Shape Influence Wake Reattachment

A critical aspect of aerodynamic efficiency is airflow reattachment, meaning the air transitions from turbulent to smoother flow along surfaces after initially separating. Rim width, shape, and profile play significant roles in how effectively airflow reattaches, particularly after being disturbed by other bicycle components.

At FLO Cycling, we’ve carefully optimized our rim shapes and widths to facilitate better airflow reattachment at realistic yaw angles. Here’s how each of our wheel models addresses these aerodynamic challenges:

FLO 49 AS: Our versatile mid-depth wheel features a rim profile engineered for smooth airflow reattachment in varied conditions. Its width and shape ensure airflow remains stable and predictable after encountering turbulence from the frame, rider, and other bike components, resulting in a balanced aerodynamic performance suitable for diverse riding conditions.

FLO 64 AS: This deeper wheel is specifically optimized to manage wake interaction at higher speeds and in typical road racing or triathlon scenarios. The carefully sculpted rim profile effectively promotes airflow reattachment, minimizing the aerodynamic drag caused by turbulent wake from the front wheel and bicycle components.

FLO 77 AS: Designed for ultimate aerodynamic performance, the FLO 77 AS excels at managing complex wake interactions prevalent at aggressive yaw angles commonly encountered in time trials and triathlon races. Its deeper rim profile ensures minimal airflow separation and rapid reattachment, significantly reducing total aerodynamic drag for improved speed and efficiency. Our modeling showed tri bikes specifically benefit from a deeper rear wheel based from frame geometry. 

FLO G700: Gravel cycling presents unique challenges, with broader tires and frames creating increased turbulence. The G700 wheel addresses these conditions with an optimized rim width and profile designed specifically for improved airflow management, ensuring effective airflow reattachment despite the highly turbulent environment typical of gravel riding.

Front and Rear Wheel Combinations for Optimal System Aerodynamics

Given the complex aerodynamic interaction between front and rear wheels, selecting optimal combinations becomes critical. The front wheel greatly influences the airflow experienced by the rear wheel, thus pairing complementary front and rear rim profiles can significantly enhance total system aerodynamic performance.

For example, pairing a moderately deep front wheel like the FLO 49 AS or FLO 64 AS with a deeper FLO 64 AS or FLO 77 AS rear wheel can yield considerable aerodynamic and handling benefits. The front wheel, is stable in gusts and our wheels are designed to handle initial airflow smoothly and efficiently. This creates a more predictable wake, which the deeper rear wheel is designed to manage effectively, minimizing overall drag. You can handle a deeper rear wheel since it has no steering axis and isn’t impacted by gusts the same way. A staggered wheelset also moves the center of pressure to rear of the bike increasing hanlding.

Similarly, gravel riders can optimize aerodynamics with the FLO G700 wheelset designed specifically for stable airflow management under turbulent conditions. The broader rims on these wheels specifically address airflow disruptions caused by wider gravel tires and frames, maintaining effective airflow reattachment and stability.

Practical Implications and Real-World Performance

The real-world impact of optimizing wake interactions through strategic wheel combinations includes:

• Reduced Total Drag: Improved airflow management significantly reduces aerodynamic drag, directly translating to watt savings and faster speeds.
• Enhanced Stability: Efficiently managing turbulent airflow reduces handling instability, particularly in gusty conditions, allowing riders to maintain better control and confidence.
• Consistency Across Conditions: Properly designed wheel combinations ensure predictable aerodynamic performance across various conditions, essential for competitive racing and endurance events.

At FLO Cycling, these insights have driven our design philosophy, emphasizing comprehensive aerodynamic optimization rather than isolated improvements.

Real-World Validation and Testing

While Computational Fluid Dynamics (CFD) simulations and wind tunnel testing are indispensable tools for initial aerodynamic design, they are useless without input from the rear world. At FLO, our real world data collection, including over 100,000 data points, ensures our wheel designs excel not just in idealized conditions but precisely where cyclists need performance most—on the open road.

This rigorous approach ensures each FLO wheel model is proven to handle real-world yaw-angle variations effectively, giving riders the confidence that their wheel selection genuinely enhances their overall cycling performance.

Conclusion

Aerodynamic performance in cycling extends beyond individual wheel profiles—it’s about understanding and optimizing complex interactions between front and rear wheels under real-world conditions. At FLO Cycling, we design our wheels to leverage these interactions, carefully managing wake turbulence and optimizing airflow reattachment for maximum efficiency.

Whether you’re competing in road racing, triathlon, or gravel cycling, selecting wheel combinations designed with real-world aerodynamic interactions in mind—like our FLO 49 AS, FLO 64 AS, FLO 77 AS, and FLO G700 wheels—can offer substantial performance advantages. After all, your wheels shouldn’t just perform individually; they should excel together as a cohesive, aerodynamic system.