Ducati's Brno Fairing - Danny Aldridge Explains Whence It Came And Why It's Legal

The Brno round of MotoGP turned out to be a veritable bonanza of aerodynamic developments. Honda turned up with their previously homologated fairing, and Yamaha debuted a new fairing with a modified upper half at the test on Monday. But it was Ducati who stole the show, with a radical new design featuring a large side pod which looked remarkably like a set of wings with a cover connecting them.

That fairing triggered howls of outrage from fans. How, they asked, was this legal? The fairing appeared to have two ducts which came out at the top at right angles, then return to the fairing at right angles. That turned out not to be the full shape of the fairing, when Danilo Petrucci sported one where the bottom half of the side duct extended lower. It seemed to be a blatant breach of the rules.


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The problem, MotoGP Technical Director Danny Aldridge explained, lay in part with framing of the rules. When Dorna demanded a ban of the original winglets, they sat with the manufacturers to draw up a set of regulations which would limit aerodynamics and eliminate the risks, yet at the same time would allow some amount of development. That proved impossible to do with the manufacturers so split among themselves, and so Dorna had to try to come up with a set themselves.

Factory rules

"To go back to the beginning, we requested to the manufacturers, 'you give us some rules'. And they couldn't," Aldridge told us when we spoke to him about it at Brno. "Maybe the rules are too open at the moment," he said, acknowledging the difficulties the ban on winglets has created.

Aldridge contrasted Yamaha's aerodynamic package with the fairing Ducati debuted at Brno. "If you take the Yamaha design, it has a bulge on each side like this," Aldridge said, making a smooth curved shape with his hands. "Then if you take the Ducati design, it also has the bulge on each side but like this," this time, making a much more squared off shape emulating the Ducati fairing. "If we say the Yamaha is correct, at which point does it go from correct to not correct?"

"This is the problem," Aldridge continued. "You would need to start defining acceptable curvature and we don't have that in the rule book now. I will speak to the manufacturers about the present rules, if they feel they are not working or they are not happy. They have not come to me about it, but that would be my general opinion if they did; we would start to look at defining curvature and angles."

Meeting of minds

Yet there is already a dividing line between what is legal and what is not. At the moment, that dividing line is drawn up by Danny Aldridge based on the wording of the regulations. Aldridge does not do this alone, however. "With all of these aero packages, the rule book states the final say is mine, but I understand that it's such an important decision so I also speak to other people such as [Race Director] Mike Webb and [MotoGP Director of Technology] Corrado Cecchinelli. We sit down as a kind of mini-committee. I get their opinion and input until we get to a point where we all agree it's within the rules. That's when I allow it."

The defining principle behind such calls is still safety. "The most important factor is safety," Aldridge told us. "No sharp edges or something that could be dangerous to themselves, other riders or track marshals. And it must still be within the rules as far as the use of aerodynamic devices. You obviously can't take parts or material off so that it turns into a wing." He was aware of Dani Pedrosa's comments on the new fairing, but had not received a formal complaint. "If we received a concern from the riders through the Safety Commission, or Race Direction, we would definitely look at it. One option might be to limit the opening of any ducts. Most riders don’t seem too concerned."

Aldridge does not take the responsibility for ruling on the legality or otherwise of aerodynamic packages lightly. "It has given me sleepless nights for sure," he admitted. "Because the rules have both helped and hindered us. I'm trying to be fair to everyone and every decision sets a precedent. You’re always thinking, 'how might this evolve?' So it really helps talking everything through with Mike and Corrado. Three heads are better than one in some respects."

Iterative design

That process of consultation was one of the reasons the new Ducati fairing took such a long time to actually be used on track. The first version of the fairing was a long way from being legal. "The design and homologation process has been going on for a few months. The first design they submitted, we said 'no, you need to change this'. So it's not a case they got everything they wanted," Aldridge said.

It took an iterative process for Ducati to come up with a fairing which the Technical Director was willing to accept as legal, with Ducati returning with a new design four or five times before Aldridge was willing to give his blessing. The process involved Ducati submitting a design, and Aldridge rejecting it and stating the reasons why it wasn't legal.

That is just the way that the rules work, Aldridge says. Once the rules have been drawn up, engineers start looking for the loopholes left by the letter of the law. "Their job is to get to the limit and my job is to keep them within the limit," Aldridge says. "So it's finding a compromise. So what happens with the first design - and this has happened with other manufacturers as well obviously - is they say 'is this allowed?' And I say, 'no, what you need to do is adjust this, this and this' and so they come back with a version two, version three, version four."

The final word

That the legality of a particular design is a matter of interpretation is a fact of life, Aldridge says. "The rules say it is down to the Technical Director's interpretation and of course everyone has a different interpretation. Some people say 'it's a wing, it shouldn't be allowed', others say they like it and understand why it was allowed. 20 people will give 20 different views." Adding more and more detail to the rule book would not prevent the arguments, though. "In F1 the aerodynamic rules are very strict, but they still have arguments every week about the developments," Aldridge pointed out.

Perhaps the main reason fans objected to the Ducati aerodynamic fairing shown at Brno is because the first version the public saw was the version with just the upper duct, which features a sizable loop, rather than the full version which extends much lower down the fairing and seems slightly more reasonable. That image of the short fairing sporting what appeared to be a set of wings was a shock to the system.

Is Ducati's fairing the absolute limit of what is allowed under the rules? "Definitely," Aldridge emphatically replies. "Honestly, we've been going to meetings with them for the last four or five races so there is not much more [that would be allowed]. A lot of people don’t like it, and I understand, but I think if you see the full version it is not as bad as if you only see the half version."

He also explained why the two different versions of the fairing count as just a single update. "They have two versions [of the fairing]," Aldridge told us. "They have the horizontal piece in the middle and, within the rules, you are allowed to remove material. So what they did was make it as one solid piece, it's not hollow, and then they can cut off [the bottom part], smooth off the cut and paint it. Very clever."

Hacking the rules

There is a difference between the Honda, Yamaha, and Ducati fairings, however. Ducati's new fairing is an update, and can only be used with either the upper, or both the upper and lower ducts fitted. Honda and Yamaha homologated their fairings including side ducts at the beginning of the year, but the side ducts were detachable, allowing them to either fit them or remove them at particular tracks, depending on need. "As the rules are written, they need to be an integrated part of the fairing," Aldridge explained. "The Yamaha and Honda are bolted or riveted on, but the top part on the Ducati is molded into the fairing."

Yamaha's removable duct meant that they were able to introduce their update in Austria, after testing it at Brno. That fairing update featured a more wedge-like upper nose section, a little like the KTM, and including the side ducts used previously.

That the Yamaha upper fairing should resemble that of KTM is unsurprising. Factories are forever copying each other's designs, or if not exactly copying them, then taking what they see and trying to refine it. As a result, the designs tend to converge in the end. "There will be a lot of evolution," Aldridge said. "As always in motorcycle racing, development goes off in different directions at first and then they all move closer together again. The nose of the Ducati for example is the extreme of the KTM and the lower fairing is the extreme of the Suzuki. So they've gone to the limits. So this year we'll probably see some way out stuff and then you might find next year all of the bikes start to merge towards a similar design."

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I think I predicted this about what, 6 or 7 times? Why is it always short-sightedness that wins out? Why always knee-jerk reactions like flat out banning things? Don't they know that after more than 50 years of drawing up technical regulations that that never works? Ever?

Answers on a postcard.

this explains why Ducati were seemingly so long in providing aero to Jorge Lorenzo. Thanks very much David.

"So what they did was make it as one solid piece, it's not hollow, and then they can cut off [the bottom part], smooth off the cut and paint it. Very clever."


I am keeping in mind that the increased aero effect of wings last year made for a bike that was a LOT more demanding to ride. The forces are felt. It isn't a panacea. It took a bit of top speed out of last round's Ducatis running it. But allows more power unleashed w/o wheelie of course.

Interesting indeed that Lorenzo has a preferable front end for his cornering style with it. I had not anticipated him experiencing that to the degree he just did. And the bike did not appear to have some of the more violent unruly behavior at speed that the bi-plane winglet one could have a year ago.

I am enjoying it. More so than the electronics heyday we just finished, as we could only see the result and none of the mechanism. On display for commoners to ponder and competitors to plunder. Like the old days!

You're comment about the end of the electronics era and the start of the aero era make me think: how long until we get control fairings?  We already have control tyres, control electronics, every bike using the same brakes, and almost every bike using the same suspension.

Funny thought.

Methinks we are about to see a flurry of testing on increasingly sized aero fairings for next year, and a rule change (AGAIN) after Dorna and a few manufacturers struggle with it. Likely Honda vs Ducati w a handful of Dorna staff in the crossfire.

Last time Ducati lost out. For a half season? The crafty fast moving buggers are back on top (and "out at the bounds?") now and will certainly get a response soon from Honda.

My favorite thing about this aero movement (in addition to it being visible, understandable, and easily heisted) is the structural change of power in the series that continues. Yamaha is copying KTM, Honda is on it's back foot, and Dorna is not held by the bullocks by Honda. This tech is more accessible to smaller teams since it can be replicated relatively easily. Honda has Marquez. But they don't have the whole series by the balls.

I don't think I will want to be a part of the commentary two-step here that follows. We all knew how we felt about the electronics doing turn by turn. The torqueductor. The overnight special tires. Here come the same folks with the same basic two frames of reference re pure prototype or "better racing." Then we get to enjoy the tech geek folks here, some are REALLY gifted and insightful re the engineering (thanks!). Criticism of Dorna with armchair marketing geniuses that have pet engine preferences (yes, I am one too re the triple we just got for Moto2). Then come "we need tire wars" followed by "we need 2 strokes" until the discussion fizzles not without personal attacks, fan boyisms, and accusations of such usually by them.

(Sigh) This is a REALLY cool era. And SO much to see, appreciate and consider that we aren't likely to slip back into shoddy shite in the comments here again. It was a sign of the times. Look, a pure prototype journalism and online community!
The war never ends.

Just thinking if there are more European manufacturers in MotoGp perhaps Honda won't have it all their own way.

Honda once held all the power in the MSMA, now with KTM & Aprilia as well as Ducati I am hoping that may change! If we had one more Euro brand for example BMW or MV Agusta then the balance of power may shift from Japan towards Europe. Not sure if I want the Italians to have all the influence. A change might be good.

What do you reckon David?

Yes Motoshrink I am in the "I want two strokes" camp. That is what I grew up with. The smell of two stroke exhaust is the smell of Grand prix racing to me. surely 2T in one class is possible, they are cheap to run, maintain & repair.

Yes, this is a REALLY cool era, this to shall pass.