Is Ducati using ground effect for more grip in MotoGP?


Ducati unveiled its latest aero at the Qatar tests – is the Italian factory using downforce to increase cornering grip, a new area of MotoGP aerodynamics performance?

Pirro Ducati aero detail 2021 testing

The ‘downwash duct’ creates downforce at high lean angles


Ten years ago I interviewed revered Formula 1 engineer John Barnard about what he would do to MotoGP design, given a big, fat, F1-style budget. The man who introduced the carbon-fibre composite chassis and semi-automatic gearbox to F1 had recently completed several years working on ‘King’ Kenny Roberts’ MotoGP project, where he never had the resources to explore the areas of performance he wanted to explore.

MotoGP aerodynamics was an area that particularly fascinated him because the science was so advanced in F1 but at that time had hardly been touched upon in bikes.

F1 cars get much of their staggering corner speed from aerodynamic downforce, sometimes called ground effect, which uses low pressure between car and racetrack to suck the car into the asphalt, generating massive amounts of grip.

Barnard was already wondering if he could use ground effect to create more grip in MotoGP.

“A racing motorcycle is more like a jetfighter than a car”

“When you’re talking about 60 degrees of lean you’ve got a lot of fairing close to the ground, so what’s that doing and what could it do is a big question,” he said.

I thought this was somewhat fanciful, because a section of bodywork on a two-wheel vehicle could hardly be more different than the underside of a four-wheel vehicle. Then I remembered chatting with Team Roberts engineers Mike Sinclair and Warren Willing in the 1990s. I asked the pair – two of the brightest minds in motorcycle racing at the time – if motorcycle traction control would one day be as clever as F1 traction control.

No, they said: motorcycles are much more complicated than cars because they lean, pitch and yaw, plus the size and shape of the tyre contact patch constantly changes, sometimes the front wheel is in the air, sometimes the rear wheel in the air and so on. Willing told me, “A racing motorcycle is more like a jetfighter than a car”.

In the end science proved Sinclair and Willing to be wrong. So perhaps ground effect can be made to work on MotoGP bikes, creating more grip for faster corner speeds and faster lap times.

Ducati is the king of MotoGP aerodynamics. Gigi Dall’Igna and his vehicle dynamics engineers have spent the last five seasons developing bodywork designed to reduce wheelies, to allow the rider to use more throttle exiting corners, and increase braking stability, to allow the rider to brake later.

The new aero Ducati unveiled in Qatar at the weekend suggests that Ducati is now exploring other areas of aerodynamics. The big question is this: is Ducati chasing ground effect to increase cornering grip?

2021 MotoGP Ducati

The Ducati’s front- and rear-wheel covers generate downforce at high lean angles


In fact, motorcycle racer and Formula 1 aerodynamicist Ali Rowland-Rouse believes Ducati has been using ground effect since 2019, when it first attached wheel covers to the lower area of the Desmosedici’s wheels.

“The wheel covers do two things,” says Rowland-Rouse. “First, they clean up the airflow around the wheel in a straight line. Second, they are downforce-at-lean-angle devices, because when you’ve got a flat surface near the ground at speed, with air passing between the two, you lower the pressure between them and you end up with downforce.”

“Most MotoGP aero is designed to produce downforce when the bike is upright. Once you go over 45 degrees of lean you have more side-force than downforce, which increases the lateral acceleration through the corner, which is what the tyres are fighting against, so these wheel covers are downforce devices that create suction when the bike is leaned over.

Ducati didn’t use its wheel covers during the Qatar tests, but neither did they during last year’s preseason tests at the track and neither did they use them at Phillip Island in 2019, another windy MotoGP venue. Instead test rider Michele Pirro and 2021 factory riders Jack Miller and Pecco Bagnaia tested a new aero feature in the Desmosedici’s lower fairing, something never seen before in MotoGP.

“They’re cleaning things up, to reduce drag and increase top speed.”

The new aero features a duct on either side of the fairing lower, taking air that’s travelled either side of the front wheel, turning it almost 90 degrees and ejecting it downward.

“This is the first time we’ve seen fairing aero elements so low down and close to the track,” adds Rowland-Rouse. “It’s a downwash duct and at high lean angles it’s very close to the track, so it produces downforce.”

Miller revealed on Sunday night that the new aero does indeed make the bike seem more stable, which suggests that Ducati is indeed working in this area.

However, Rowland-Rouse thinks the downwash ducts may have a greater effect on several other performance factors.

“The trailing edge of the middle wing [between the top wing and the downwash duct] is higher than the leading edge, which produces lower pressure under the wing, which sucks the bike down. The downwash duct is the opposite, which produces lower pressure above the duct, which increases the power of the wing above it. That’s one thing.

“The next thing is that the airflow beneath a motorcycle fairing at high speed is a mess. The front wheel creates a lot of wake, which creates turbulent, low-pressure air beneath the bike and a wash at the back of the bike, like a truck. All this creates a lot of drag. So this downwash duct fires air beneath the bike to increase air pressure in that area, which reduces drag.

“This has two effects. Not only does it reduce drag to increase straight-line speed it also cleans up the airflow at the back of the bike, which makes it more difficult for riders to get a free tow from the Ducati.

“It looks to me like the overall design of the bike’s bodywork is sleeker than it’s been for a while, so instead of focusing on downforce like in recent seasons they’re cleaning things up, to reduce drag and increase top speed.”

Mustang P51

Could the P-51 Mustang’s under-fuselage radiator design be recreated in a MotoGP bike?


Will Ducati’s latest aero designs encourage more protests from rival manufacturers? We don’t know yet, because the factory has yet to homologate the kit. Engineers will either homologate the downwash ducts for the first race or further refine the design back in Bologna.

What we do know is that Ducati is the only MotoGP manufacturer that wants to continue aero development at the current rate. Two years ago – after the controversy over Ducati’s so-called rear-tyre cooler – I interviewed engineers from all six factories. Dall’Igna was keen to increase aero knowledge, while Aprilia, Honda, Suzuki and Yamaha all agreed they didn’t want aero development to continue at such a pace, while KTM wanted all aero devices banned.

“Our opinion is that we want to develop technology that can be transferred to streetbikes, which is why extreme aerodynamics is not the right way to go,” HRC technical manager Takeo Yokoyama told me.

Aprilia’s chief engineer Romano Albesiano had similar feelings.

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“As a technician I like aero, but I would keep things as they are now, with clearer rules,” he said at the time. “The perfect thing would be to have some aero development without an explosion of costs, but this would require an expert in aerodynamics to manage the rules, so maybe MotoGP needs an aero adviser, perhaps from Formula 1.”

Of course this doesn’t stop Albesiano from dreaming. The former Cagiva 500 chassis designer is keen to introduce the Meredith effect to MotoGP. This phenomenon – discovered by British engineer Frederick Meredith in the 1930s – uses careful design of the cooling system to use heat produced by the radiator to create thrust, because heat adds energy to the airflow.

Most famously this effect was used in the Second World War P-51 Mustang fighter, with heated air exiting the radiator generating a slight amount of thrust. More recently the phenomenon has been used in Formula 1 cars, with radiators mounted in sidepod tunnels.

Providing adequate cooling for racing engines is a huge issue, because the larger the radiator the greater the drag. So if you can use kinetic energy from the radiator’s heat to offset that drag it’s an important gain. But whereas a car has room for radiator tunnels a MotoGP bike doesn’t; certainly not in a conventional configuration.

“The dream of every motorcycle engineer who looks at an F1 car cooling system is to apply this system to a motorcycle, because if we can create this kind of optimal cooling system we get thrust from the radiator, not drag!” says Albesiano. “On motorcycles we’re far from being able to use the ‘push’ coming from the radiator, but maybe we can at least get close to that effect and do something better than a conventional motorcycle cooling system.”