A storm is sweeping across Europe today, the perfect opportunity to discuss the influence of wind. Last week, I delved into the topic of why cycling is slower in winter. Today, we'll address another pressing question: do you genuinely encounter more headwind than tailwind, or is it just a perception? To cut to the chase, it's not merely a perception; you do indeed face more headwind. Here are the three primary reasons for this.

1. Riding against the wind slows you down

When we consider the actual time spent riding, you're likely to find that the wind is working against you more often than it's at your back. This is simply because you travel slower when riding into the wind compared to when it's behind you. So, if you embark on a 60-kilometer round trip with 30 kilometers of headwind and 30 kilometers of tailwind, your speed against the wind might be 25 kph, which translates to a challenging 1 hour and 12 minutes. In contrast, when you have the wind at your back, you can maintain a steady 40 kph, taking only 45 minutes. Consequently, you experience almost half an hour less wind resistance with a tailwind than when facing headwind.

2. No wind equals headwind

The second and third reasons are a tad more intricate. Apart from gravity, which primarily affects uphill cycling, various forms of resistance contribute to the difficulty of cycling. Not all the power you exert on the pedals translates into forward speed due to these resistance factors. Rolling resistance, for example, represents the energy lost where your tires contact the road and in all bearings. However, air resistance takes the spotlight as the most significant form of resistance. In essence, as you move, you're consistently colliding with the air ahead of you. You must displace the air in your path before you can make headway. This is why cyclists prioritize aerodynamics - being more aerodynamic makes it easier to cut through the air and progress with less effort.

Hence, it's a distinct advantage to draft behind another cyclist. The lead rider pushes aside the air, creating a slipstream that facilitates your passage. Nonetheless, even in the absence of a pacemaker or any substantial wind, you're still responsible for moving the air in your path. We term this "riding the wind" - the airflow generated as you displace the air. As a result, when there's no perceptible wind, it still feels like a headwind due to this natural resistance.

3. Headwinds always oppose, but tailwinds aren't always in your favor

Regrettably, the presence of wind, whether against or with you, doesn't alter the fundamental dynamics of air resistance. When you're battling a headwind, the air you intend to navigate through pushes back, making cycling a bit more challenging, even at low wind speeds (e.g., wind force 1). On the other hand, with a tailwind, you might be pedaling faster than the wind itself. For instance, if the wind force is 1, the air is moving at a speed between 1 and 5 kilometers per hour, while you're cruising at 30. Consequently, you still need to displace a significant amount of air in front of you, which can create the sensation of a headwind.

Think of it like moving through a crowd of people on foot. When you move against the crowd, it demands considerable effort. Even when you move with the flow, if others are walking much slower than you, it can still be a struggle. Only when everyone is moving at your speed or faster does it become genuinely easier. For most cyclists, it's usually only when the wind reaches force 4 or higher (refer to the Beaufort scale) that they can match or exceed the wind's speed, eliminating the feeling of a headwind. Consequently, the wind often blows at a speed where, when facing it, you're significantly affected, but with it, the advantage is limited.

Indoors, the dynamics change

During indoor cycling, the wind becomes your ally, and a headwind is now a necessity. You may find yourself cranking up the fan to its highest setting. Without the natural airflow, it's more challenging to dissipate your body heat. In conclusion, understanding the nuances of headwinds and tailwinds sheds light on the intricate relationship between cyclists and the ever-present force of the wind, revealing that when it comes to cycling, not all winds are created equal.