Winglets may have been banned for 2017, but the drive for aerodynamics development continues. This time, however, winglet development will continue on the inside of the fairing, rather than the outside. The development ban applies solely to the exterior surface of the fairing, and not the interior.
What this means in practice is that while the shape of the fairing must be homologated at Qatar, with one update allowed during the season, that only applies to the outer surface of the ducts, and not to the vanes (the small struts or winglets inside the ducts which control the airflow and can be used to alter downforce) inside those ducts. Development of aerodynamic control surfaces will still be allowed, as long as the changes remain on the inside of the fairing.
An eagle-eyed MotoMatters.com reader spotted the gap in the regulations. Section 184.108.40.206.10 of the FIM Grand Prix Regulations reads as follows:
Only the external shape, excluding the windscreen, is defined in this regulation, so the following parts are not considered as part of the Aero Body: windscreen, cooling ducts, fairing supports, and any other parts inside the external profile of the bodywork.
When reached for comment by email, MotoGP Technical Director Danny Aldridge responded "You are correct in the fact that I only control the external shape/profile of the fairing. Meaning, Yamaha can in theory change or adjust their inner supports as often as they wish. When the regulations were being discussed with the MSMA, this was one of the criteria that they requested in the wording of the regulations."
The shape of Yamaha's new fairing helped to give the game away. As you can see in the photo by Andrew Gosling below, Yamaha's fairing consists of an outer duct fitted to the exterior of the fairing, with two supports or vanes on the inside. Yamaha can alter the position, size, and shape of those supports to suit the characteristics of each different track, or as they learn more about the performance of their ducted vane fairing.
On Thursday, Suzuki and Aprilia also rolled out their new aerodynamic fairings. Both took a different approach to creating downforce and aerodynamic surfaces to Yamaha, as you can see in the photos shared on Twitter by WorldSBK commentator and Paddock Pass Podcast regular Steve English.
The solution selected by Suzuki most closely resembles the Yamaha design, though its placement is very different. Where Yamaha chose to put its duct on the upper part of the mid fairing, Suzuki have added it on the side of the nose. Clearly visible in English' excellent picture is the central strut or vane which will provide downforce. Suzuki are free to modify this vane as much as they like.
Aprilia's solution is very different, consisting of an open aerodynamic duct either side of the nose. Downforce in this design is generated by the shape of the inner channel, and the shape of the outer duct. There does not seem to be as much room for internal modification of the duct as on the Suzuki or Yamaha.
Aprilia's design may also spark debate over what constitutes the outer surface of the fairing. The wording of the rules is ambiguous, though an initial reading of the rules suggests that the inner surface fo the duct is not considered to be a part of the "external profile" of the fairing.
The wording of the new regulations also makes clear that the ban on winglets was only introduced on the grounds of safety. And in a sense, the rule makers were bound by this, as the Grand Prix Commission only has the right to ban a technology on safety grounds, if the manufacturers in the MSMA want to allow it.
By having enclosed, smooth surfaces on the outside of the new aerodynamic fairings, the manufacturers are complying with the rules on safety grounds, while continuing their development of aerodynamic fairings and exploring the effect of downforce on motorcycle dynamics. Though many senior officials inside Dorna feared the cost explosion which will likely ensue from allowing aerodynamics, the genie is out of the bottle, and they have no grounds to ban it.
With Yamaha, Aprilia and Suzuki having unveiled their aerodynamic solutions, we now await what Ducati, Honda and KTM will do. Ducati have already hinted that they are keeping their aerodynamics under wraps until Qatar - either the test, or a private test before the race. Honda remain evasive, but are likely to also have some form of aerodynamic assistance before the start of the season. Only KTM have shown no interesting in developing aerodynamics so far. But as this is their first year in MotoGP, the Austrian factory already have a massive list of areas they need to work in.
The good news for riders of road motorcycles is that the designs being tested in MotoGP are far more likely to make it onto road bikes than the previous generations of winglets. Getting type approval for motorcycle fairings with internal aerodynamic devices is far easier than for fairings with external wings attached. How quickly this technology actually trickles down to street bikes remains to be seen.