MotoGP: Aerodynamics after the winglet ban

"You can’t fence in the countryside" is a phrase that denounces the futility of prohibiting, restricting or vetoing ideas or obvious situations. The preceding concept is applicable to the coming ban imposed on winglets, wings, spoilers—call them what you will—by MotoGP’s GP Commission for 2017. Especially after engineers found that these aerodynamic appendages indeed have been a step forward in the performance of their bikes on track.

And knowing the race engineers, you can bet that they are not going to give up that advantage in any way. Prohibiting external wings with a debatable argument about the danger they pose to other riders in a collision only gives engineers a green light for more creativity. Their reaction is, “Well, don’t worry, we'll create the same effect on our bikes but in a different way.” And that is exactly what some teams are already working on. We know of at least one, and if they prove successful, you can bet that the rest will follow in this circumvention of the ban.

The advantages of winglets

At this point we know that there are basically two advantages the wings created for MotoGP: reducing the wheelies and keeping the front wheel firmly on the ground. While those two aspects may seem the same, they are not. The first—wheelie reduction—is through the downforce generated by winglets to help prevent the electronics from cutting power to the engine when they detect that the front tire is too high in the air.

The second effect the wings have is to generate load on the front axle which establishes firm contact between the front tire and the ground, allowing the rider to feel it at all times. As the engineer we consulted for this article explained, this load would be very easy to calculate if you had certain parameters, such as size or angle—the angle of the spoiler relative to the horizon—and this is directly related to speed: the more speed, the more load. Thus the effectiveness of deflection increases with increasing speed in the exits of corners, in fast corners or on the straights.

There is a third effect, although this can be considered a consequence of the second, which is a better position of the front tire during the initial application of the brakes. With more load on the front tire, there is a larger contact patch when braking begins at high speed; the tendency for the tire to lose traction is reduced, and considering the immense power of the carbon/carbon brakes, this is a definite advantage. The rider has to spend less time and concentration making sure the front tire is loaded before really applying braking power.

So with the ban on the wings starting next season, theoretically all these dynamic benefits are lost. Or so some think. Does anyone really believe that the engineers are going to give up these advantages because of the new rule?

The alternative

What will the engineers come up with in seeking to reproduce the advantages of the winglets without actually having them? One creative example is a constructor who is experimenting with a double-walled fairing. An approach that basically attempts to use airflow between the two walls to generate the same downforce as the external winglets.

Between the hollow walls of the fairing are a series of deflectors that, depending on the angle, generate the desired effect. The new rule prohibits aerodynamic appendages attached to the outside of the bike—so the team have put them inside the fairing. This way they are no longer a danger to the safety of the riders, as was the argument for the ban.

The manufacturer in the championship that is working on these double walled fairings has encountered a problem, though: In tests so far, they have suffered engine overheating. The need to balance airflow into the double-walled fairing and the radiators is one that likely has an easy solution. It’s going to take much more than a simple problem like this to stop this impending development.

Being an absolute layman when it comes to aerodynamics, the double fairing with internal deflectors strikes me as a streamlined approach from F1. I think the wings attached to motorcycles are much more basic, and therefore much less expensive. The cost of entering into an unrestricted aerodynamic development war has been among the arguments in the discussion of the wings. Without a comprehensive rule with less loopholes, now the engineers are working on alternatives that are much more complex, and therefore more expensive.

Can you imagine, for example, if these deflectors inside of the fairings were mobile and could function like flaps of an aircraft to help turn the bike on corner entry? "This would be forbidden," responded Honda’s Shuhei Nakamoto flatly when asked about the issue. "Movable aerodynamic parts are prohibited by the rules." Indeed, in the FIM World Championship Regulations, paragraph 2.4.4.7, is item #8, where it talks about the wings, and at the end there is a phrase that says moving aerodynamic devices are prohibited. When I read it, I interpreted it to be referring to the wings as part of that point 8; but Nakamoto instead claims that it is in general.

As a warning regarding the “Pandora’s Box” that the GP Commission has opened by enacting a simple ban on winglets is the statement to our Italian colleagues at GPOne.com by David Tardozzi, the Ducati Team Sporting Director: "As in F1, we will be examining the rules very carefully. Every word is important because everything that is not prohibited will be permitted."