‘MotoGP would be a completely different game without downforce aero’

And in which attitudes do you test the bike? Presumably, you need to go from upright to maximum lean and pitching forward and back…

You can do many things with the bike in the wind tunnel, but it’s quite difficult to have accurate measurements for these complex load cases [the distribution of forces] and also quite difficult to analyse.

So it’s much easier to simulate all these different load cases in CFD. Then the wind tunnel is more about validating the CFD. It all depends which areas you’re interested in, or where you’ve found some mismatches; then you try to replicate that in the wind tunnel and validate things.

Do you use your MotoGP riders in the wind tunnel or mannequins of your riders?

We work with riders.

Presumably you can’t use Brad Binder, Jack Miller and your GASGAS riders all the time, so do you have doppelgängers?

Yes, we do, but when we bring our riders to the wind tunnel it’s more about individual set-up, with their leathers and other riding equipment, plus things like stability, which can be quite difficult to measure but are very easy for the riders to understand.

This year’s RC16 fairing is fitted with diffusers, which are smaller than Ducati’s, so much effect do they have?

I don’t see them as separate components or add-ons. They are part of the concept of how we’ve shaped the fairing and they are big enough to control the airflow according to the fairing shape.

To give you an example, we also had some fairing options which created the same effect without the diffusers. The thing is to get the flow you want and how you do that is up to the creativity of the engineers.

Do your diffusers create a low-pressure area?

Not directly, no.

But the slab-side fairing does create some ground effect?

When you want to use ground effect you need your aerodynamic body close to the ground and you need to control the airflow around it. That’s what the diffusers do – they clean up the flow, make sure it goes where we want it and they make the flow stable.

Last year you struggled with turning, forcing riders to use longer, more rounded lines, so has this new aero helped in this area?

In the end it’s the package of the whole fairing, but, yes, I do think we’ve made a step with the fairing.

You work in Toyota’s wind tunnel in Cologne, right?

This I cannot say.

All this aero – downforce and ground effect – must increase mid-corner forces, so does it affect how stiff you make the RC16’s chassis?

During the last few years aero development has changed a lot how the rider uses the bike, how we set up the bike and what kind of forces we have at what moment. So globally, I’d say, yes, but talking particularly about mid-corner, I don’t think so.

What effect does downforce aero have on tyre life?

It depends how you work the tyres generally with the bike. Looking back at last year we had big problems overloading the front tyre. I wouldn’t say we had too much downforce and I also wouldn’t say we have less now, but we’ve found a way to make it more useable. And it’s clear that you can affect tyre life with the aero, in a positive or negative way.

What about geometry changes? For example, Yamaha engineers say they’ve used the effect of downforce aero to change the M1’s geometry for better drive out of corners.

Yes, exactly. In the end, bike balance is the cumulation of the way the rider rides, the set-up balance and the aero balance. Unfortunately the aero balance depends on the speed, so to find a compromise that fits every corner is very difficult. But for sure if you took off the wings or fitted a fairing from six years ago, the balance of our current bike would be completely out of the window.

So downforce aero has changed everything – braking, turning, accelerating – so MotoGP is a new game…

Absolutely, yes. I’d even take it one step further. It’s not just on the set-up side, it’s even how we are developing the engine. I think MotoGP would be a completely different game without this downforce aero.

Does it change engine development because you can find more corner-exit drive with the downforce and ride-height devices?

Exactly. Nobody could use all this power if all of that wasn’t there. Without all the aero a more rideable engine would work much better than a high-performance engine.

So you’re going more and more extreme with the power?

You have to, because now you need power to waste! [Because downforce equals drag.]

In the early years of modern MotoGP aero development it was all about front downforce, but now most of the bikes have rear aero too, so it must be tricky to find the right balance?

The danger when you do all of this is that the bike can feel like it’s on rails, so it’s a very difficult compromise you have to make. But for sure the target is to keep the balance more neutral and still have the bike in your hands.

Will we see more and bigger rear wings?

Of course we have to make a compromise with the Dorna devices, like the rear camera, so it’s quite a difficult area to work in, also because it’s affected so much by the airflow around the rider, which is very uncontrolled and not a reproducible thing, because the rider is always moving around.

It’s better than nothing to work in this area. Already three years ago we had some wing shapes integrated into the rear, but to get it really under control, so the rider can really use the benefit, was not so easy, so I’m not sure how radical you can go in this area.

The rider must make a huge difference to the aero when he hangs off and puts his knees and elbows on the ground?

For sure. When the rider hangs off the airflow is a completely different story. You block one side, so there’s no flow

What does that do?

It creates some asymmetrical aerodynamic forces, so the target is to use that in your favour.

Will all of this have any benefit for everyday motorcyclists?

Normal, legal speeds on the roads are too low, so if you’re talking about aero for road bikes it’s mainly about comfort and stability.

We have been working on aero with our production bikes for long time, and now we have more and more resources in this area, so we can feed more information back.

KTM has never liked MotoGP’s push towards downforce aero, so it must be a bit weird working on something you don’t want.

Here, you have to think in two different directions. One, do we believe it’s good for the sport? No, clearly not. The other is, if there’s any area in the rule book which you can exploit and gain an advantage from, then you have to use it. This is racing. So we aren’t hesitant to do it and we put in our full effort and we are also excited about what we are doing. But this is because it’s something that’s allowed, even though we believe it’s not right for the sport.

Will things change? Most manufacturers want a reduction in aero and many people believe it’s spoiling the racing…

Yes, absolutely, and safety also plays into this a lot. The performance of the bikes is getting more and more – for example how much more engine power is coming from working with downforce aero.