A few days ago, talking about the bike of Jonathan Milan, the rider of the Bahrain-Victorious he had confided in us that at the beginning of the season he had also thought about widening the handlebars, a choice that would have gone diametrically against current trends. Milan told us he'd considered this option for two reasons: breathing, as it would open up his rib cage a bit, and to ensure his elbows would stick out less and thus cause less friction. Then the Friulian decided not to change and stayed with the 400mm crease.
When we talk about friction we move on to the infinite chapter of aerodynamics and here we can only intervene Luca Oggiano, CEO of NabaFlow (a company specializing in fluid dynamics solutions), now our expert in the field. We posed the question to him, and it turned out that Milan's hunch wasn't entirely wrong. Let's see why.
Luca, would wider handlebars have been beneficial for Milan?
First of all we need to make a distinction: whether we're talking about sprints or normal running phases. Because if we talk about sprint and therefore pure power, he did well to keep it tighter, Even if the bike is more complicated to ride. While if we're talking about pedaling, we'll have to see. There are so many parameters to evaluate.
The trend today is to narrow the handlebars to be more aerodynamic…
The tighter I grip the handlebars, the more I gain as I'm less exposed to the wind: in theory it's like this. But then you have to look at the athletes' build, which is extremely subjective. And as Milan used to say: "I squeeze the handlebars, but then my elbow sticks out." I think we've reached the limit with handlebar sizes these days. I don't think we can go much further.
The UCI has imposed the limit at 360 millimeters, no narrower…
There are also issues of handling. It's intuitive that such narrow handlebars make the bike more difficult to steer. As for aerodynamics, I'm a numbers man, and in cycling, numbers are individual. Each analysis must be done on the individual. Narrower handlebars aren't necessarily more aerodynamic for everyone.
Luca, we realize that we're speaking a lot off the cuff, but...and we had to make an estimateWhat are the differences between each handlebar size? So, 420, 400, 380 millimeters...
I believe that between one measure and another you can gain 5 watts at 50 miles an hour. But be careful, this is a value that should be taken with a pinch of salt. It's an estimate. And it varies greatly from athlete to athlete..
Very clear, but we still have an idea, so let's continue to think like this. How much can the elbows that stick out that Milan was talking aboutLet's assume that they protrude 5 centimeters outward from the front axis of the handlebars...
I could say that there is an increase in frontal impact of between 1% and 3% and therefore between 5 and 10 watts always at 50 km/h. But here the variables relating to the athlete are even more. We must understand that the aerodynamics are very particular. Let's take the example of the elbow. It's not just its impact with the air that counts, but also the trails it creates on the rest of the body, the flows… It is a study of enormous complexity.
Milan also told us that it has decreased in thickness, so 5 millimeters compared to the beginning of the year…
In this case, the advantage is frontal. He reduced the frontal area, but in aerodynamics, the shape, the CD coefficient, is very important. I can also reduce the frontal impact, but at the same time see that the CD increases due to flow issues. Let me give you an example: I have one square meter of air in front of me, and you have two. In theory, you're twice as resistant to air as I am. But then it all depends on the shape.
Very clear…
In our wind tunnel studies, it often happens that an athlete who leans lower, as Milan did, is less efficient. True, he reduced the frontal impact, but he's less efficient because the flows between the front and rear create more friction. This is why it's so important to always verify every change. And that's why simulations, track tests, and wind tunnel tests are needed. It is no coincidence that I am a supporter of the theory that not everything is right for everyone. (both for the materials and for the positions, ed.) and that, in aerodynamics especially, everything is related to the subject.
