Aerodynamics is a cornerstone of modern cycling performance, but how much of what we hear is genuine science, and how much is marketing spin?

In this episode of Performance Process, we sit down with Xavier Disley of Aerocoach to dissect the claims manufacturers make about aero gains. From wind tunnel testing to real-world application, we explore the red flags to watch for, the methodologies used to measure performance, and whether the numbers we see in marketing materials truly translate to faster speeds on the road.

Whether you're chasing every last watt or just trying to separate fact from fiction in aero marketing, this episode will help through the noise.

Podcast Outline
[00:00] Intro

• Ronan introduces the episode and the need to separate real aero gains from marketing hype.
• Introduction of guest Xavier Disley, Director at Aerocoach.
• Overview of what the discussion will cover: testing methodologies, data interpretation, and aero marketing tactics.

[02:15] Aero helmets and testing

• Discussion on Visma's use of the Giro Aerohead TT helmet in road races.
• Why some TT helmets work better for road racing than others.
• The visibility challenges of long-tail TT helmets in road racing.

[06:48] Manufacturer marketing practices and dodgy claims

• How some brands manipulate aero test results to favour their products.
• An infamous case of misleading aero data and its impact on consumer trust.
• Why independent aero testing is rare and how brands exert influence over results.

[10:03] Independence and transparency in testing

• How Aerocoach balances working with manufacturers while maintaining credibility.
• Examples of brands that have been transparent about their aero testing.

[26:11] Real-world vs. lab testing: challenges and considerations

• Differences between real-world and lab testing, particularly in the context of clothing.
• Why clothing aerodynamics are difficult to measure due to body shape and movement variability.
• The role of protocol consistency in ensuring valid test results.

[30:02] Dimples and surface textures: myths and realities

• Do dimples on wheels and helmets actually work?
• How surface textures can help—or hurt—airflow depending on their placement.
• Why some dimples might be pure marketing.

[34:53] Consumer perspective and technical coercion

• The rise of FOMO-based marketing in cycling.
• Do brands use marginal gains philosophy to convince riders they need new products.
• The emotional side of aero upgrades—do they actually make you faster or just feel faster?

[40:02] Usable aero and adaptability

• The concept of "usable aero"—aerodynamic gains that actually work in real-world conditions.
• Xavier’s personal experience with the 3T Strada and finding the right aero setup.
• Why adjustability is more important than chasing absolute aero gains.

[57:18] Real-World testing and repeatability

• Why repeatability is critical in aero testing.
• Challenges of testing in variable outdoor conditions.
• Best practices for improving repeatability, including consistent baselines and correcting for drift.

[1:00:00] Separating Wheat from Chaff: Consumer Tips

• How to spot misleading aero claims.
• The importance of looking at a company’s history of aero testing.
• Why detailed data transparency is key to believing aero claims.
• Red flags: overly optimistic claims, cherry-picked test conditions, and lack of independent validation.

[1:04:09] Evaluating aerodynamic claims in cycling

• Can we critically assess aero claims.
• Why brands rarely release full test data.
• Why peer reviewing is difficult with aero testing.

[1:07:20] Challenges in aerodynamic testing

• The difficulty of ensuring aero data applies to all rider sizes and positions.
• Why most wind tunnel tests only use one bike size—and why that’s a problem.
• The Escape Collective experience with aero testing and why results don’t always translate.

[1:09:00] Importance of adjustability in frame design

• Why a bike’s fit and adjustability can matter more than its pure aero performance.
• Example: A pro team forced to use suboptimal sizes due to sponsor constraints.
• Why an uncomfortable aero bike is slower in the real world.

[1:10:09] Manufacturers' focus on aerodynamics

• The positive trend of brands investing more in aero.
• Why aerodynamics is now expected—even for endurance and gravel bikes.
• Balancing aero gains with usability and practicality.

[1:12:28] Final thoughts

• Xavier’s closing thoughts on aero testing, transparency, and real-world relevance.
• The need for better consumer education on aero claims.
• Why aero matters, but only when it’s tested and applied correctly.
• Ronan wraps up the discussion and shares key takeaways for riders looking to optimise their setup.