On a bike, the wind is never just a backdrop. It's a constant, invisible yet voracious adversary that siphons off most of the energy produced by the cyclist. Riders have always understood that it's better to face it together. A scientific study shows just how right this intuition is, and how much it can transform cycling, even far from the professional peloton.
By Guillaume Judas – Photos: depositphotos.com
As you have probably noticed, as soon as the speed exceeds 25 km/h, air resistance becomes the main factor limiting your progress on a bicycle. In reality, air resistance becomes predominant as soon as the speed exceeds 15 km/h, even if it isn't immediately noticeable. In theory, drag increases with the square of the speed, and aerodynamic power with its cube. In practice, other resistances slightly mitigate this effect, but the trend remains very pronounced. This is why going faster or facing a strong headwind always requires more effort. This is where group dynamics come into play.
Because we're talking about a cyclist riding alone. As soon as a second cyclist gets on their wheel, the resistance is no longer the same. The rider behind immediately benefits from the slipstream and sees the air resistance drop dramatically. And The larger the number of cyclists in the line, the greater the decrease in power required for forward movement, depending on one's position within the group..
According to a study published in 2018 in the Journal of Wind Engineering and Industrial Aerodynamicsbased on CFD (fluid dynamics) simulations, which is surprising in advancetage, that is The leading cyclist also benefits from the presence of the other cyclists following him.He doesn't face exactly the same air resistance as when he's alone. This is because the turbulence generated by those behind him slightly reduces the low pressure behind him, thus decreasing the effort required by 2 to 3%. While this is small in absolute terms, what is most striking according to this study is the average reduction in aerodynamic drag for cyclists across the entire group.
As the queue gets longer, the effects become more and more pronounced. Riders positioned in the middle of the group ride in extremely favorable aerodynamic conditions, sometimes with 40 to 50% less drag compared to a lone cyclistMoreover, the average drag of the group decreases continuously with each new rider added. With eight or nine cyclists, the average aerodynamic effort is almost halved.
Strength in numbers
These results, derived from advanced numerical simulations in fluid dynamics, confirm that Riding in a group does not just redistribute fatigueThe movement of a group of cyclists following one another actually changes the behavior of the air. The peloton becomes a collective aerodynamic object, more efficient than the sum of its parts.
Added to this, of course, is the behavior and tactics of the riders within the group. As we've seen, the lead cyclist already saves 2 to 3% with one or more riders in his slipstream. These riders save 30 to 60% of their energy by taking advantage of the slipstream of this lead rider, or those ahead of them, depending on the size of the group. If they are well organized, all these runners can therefore take turns at the front, to...tagto exert effort against the wind, and recovery phases sheltered from the wheels.
Cycling is a sport where cooperation allows you to push your personal limits, and where intelligent positioning can sometimes be worth more than brute power.
What that represents in watts
To measure concretely what this means, we need to translate these percentagestages in wattsLet's take the example of an average amateur cyclist riding at 32 km/h on a flat road. Maintaining this speed solo requires approximately 230 to 250 watts, depending on size, position, and equipment. The majority of this power is used to overcome air resistance.
In a well-organized group, The same cyclist, positioned in the middle of a line of cyclists, can see the drag drop by around 40 to 45%.In other words, instead of delivering 240 watts, it can maintain the same speed with only 140 to 160 watts in a dense and well-organized group. The savings are impressive: nearly 100 watts, simply thanks to positioning.
Even the cyclist who takes the lead is not a loserWhere 240 watts would be needed to ride alone, the group effect can reduce the effort to around 225 watts in relatively stable wind conditions. Over a few tens of seconds, the difference seems modest, but repeated throughout a ride, it allows you to sustain effort longer, recover faster, and take more turns at the front without burning out.
It is precisely this mechanism explains why a group can ride fast for hourswhereas a lone cyclist inevitably ends up losing ground, even with equivalent power.
What this changes for an amateur cyclist
For an amateur cyclist, these figures have immediate consequences.They explain why a pace that seems unsustainable on your own becomes almost comfortable in a group, and why you can return from a group outing tired but rarely completely exhausted. Riding in a group is not cheating on effort: it's optimizing it..
This also means that The key to performance lies not only in individual training or increasing power thresholds, but in the ability to effectively utilize the groupKnowing how to stay close to the wheel in front, avoiding sudden movements and accepting to take short turns at the front is just as important as gaining a few watts on a power meter.
Conversely, riding poorly positioned, too far behind the wheel, or at the front for longer than necessary wastes precious energy. For the amateur cyclist, this can be the difference between finishing strong and suffering through the final kilometers of a ride or race.
Another way of thinking about effort
This scientific analysis of a line of runners changes the perception of effort in cyclingShe reminds us that performance is not only individual, but collective. In a well-organized group, everyone rides above their actual level, without necessarily realizing it.This is also what makes cycling so beautiful: a sport where cooperation allows you to push your personal limits, and where intelligent positioning can sometimes be worth more than raw power.
The group is the cyclist's most effective weapon against the windFor professionals, it's a matter of victory. For amateurs, it's a simple and powerful way to ride faster, longer, and with more enjoyment. When cycling, you rarely have to fight the wind alone, and science confirms that we're right to be wary of it.
