It's no secret that in the wake of the wing ban, MotoGP manufacturers are trying to discover exactly what they can and can't get away with in 2017.

The new rules state: "It is not permitted to add any device or shape to the fairing or bodywork that is not integrated in the body streamlining (eg. wings, fins, bulges, etc.), that may provide an aerodynamic effect (eg. providing downforce, disrupting aerodynamic wake, etc.). The Technical Director will be the sole judge of whether a device or fairing design falls into the above definition."

While '2017' machines have already been seen during testing, next year's fairing designs are far from finalised.

Ducati's decision to test with wings still fitted to its 2017 Desmosedici prompted speculation they have found a way to keep downforce while staying within the new rules. Ducati state the wings were kept for 'chassis comparisons', but if nothing else it proved that the GP17 fairing is yet to be seen.

"For next year we have to completely change the aerodynamics of the bike, and for sure we are not ready at the moment with the new aerodynamics," said Ducati Corse general manager Gigi Dall'Igna.

Meanwhile, Herve Poncharal revealed that Yamaha had 'brought a very special fairing' to the Valencia test, aimed at replicating the performance of the winglets.

As the 'sole judge' of what is and isn't legal next season, MotoGP Technical Director Danny Aldridge confirmed that Yamaha, like 'most manufacturers', has submitted a number of fairing designs for review.

"I can confirm that Yamaha have shown me various designs of fairings - and some in Valencia - to know if they will be legal or not in 2017," Aldridge told Crash.net.

"I cannot say too much about the actual designs, but I basically informed them of what would be approved and what would not. It's not only Yamaha that are submitting designs, most of the other manufacturers have also done the same."

Asked how the design submissions have been made, Aldridge responded that some manufacturers supplied 3D CAD drawings while others provided complete ready-to-test fairings.

"To me, it makes sense to work only with drawings until you get approval, but if a manufacturer prefers to produce the fairing, that's their choice and money!"

Using the feedback from Aldridge, manufacturers will complete their 2017 fairing designs ready for pre-season tests at Sepang, Phillip Island and Qatar.

But the new limit on fairing updates (one per rider, per season) raises the possibility that some teams may wait until the last moment to debut their 2017 designs, for example only at the Qatar test.

That would allow a manufacturer to check the fairing works as planned with their race riders, but make it difficult for rivals to respond/copy the design before the start of the season - at which point they are limited to only one fairing update.

Ducati chose the Qatar test to debut the new generation of MotoGP winglets, just before the opening race of 2015.