Airfoils or wings in motorcycle racing

[Motofool]

Rodger Freeth’s Aerofoil Viko TZ750A (1977):

http://www.classicyams.com/special-y...aerofoilq.html

http://www.speedzilla.com/forums/str...downforce.html

https://en.wikipedia.org/wiki/Rodger_Freeth

MotoGP:

http://www.motorcyclenews.com/news/2...gp-wings---pb/

Copied from
http://www.motorsport.com/motogp/new...r-2017-791676/

"The Commission unanimously agreed that, with effect from the 2017, the use of aerodynamic wings in the MotoGP class will be banned.

The actual regulation will replicate those for the Moto3 and Moto2 classes where the use of wings is already prohibited.

Wings that comply with current technical regulations may continue to be used for the remainder of the 2016 season."

[Racer x]

It won't or does not work because motorcycle use three axes, up down and sideways. Down force becomes up force when the angle changes. So you have to much traction then start to fly all with the twist of the throttle.
Tiny computer controlled canard type wings are something I have given a lot of thought to.

[Snake]

Cool idea!

[Mohawk]

In a straight line they are great if you have a surplus of power that effective "weight enhanced grip" will allow you to exploit. So for Racer-X land speed runs or a drag bike they are a good idea, but drag-V-down force at speed may produce slower runs. The drag dynamics of a bike mean the frontal loading transfers pressure to the rear wheel. Where as in conventional cars it loads the front & decreases rear load.

On a bike as soon as you lean it over in to a turn then fixed wings become a problem, they are now increasing the side load on the tyres & trying to force you out wide, which is bad. If they could self adjust to always be horizontal to the road surface, then they would increase mechanical grip, which would be good. If they could change there lift profile dynamically, as in one goes neutral & one goes to higher angle of attack, then they would be even more effective, but the weight & complexity of the actuator & mounting system might be worse than without. The biggest downside though is it's hard to get wings big enough to do a useful job at low speeds without getting to much drag at high speeds.

[CC Cowboy]

I have also seen proprellers on hats!

[Racer x]

Wings in land speed racing are not good. First drag is bad bad bad. Fins are OK as they create drag aft of the center of gravity.
For mile racing wings are a bad thing because it's not the speed that is the issue at this point. It's the transition from accelerating to breaking that is the danger. Imagine going 300 mph and hitting the brakes. The wing changes angle and forces the pressure on the front tire. It's already a touchy situation. A big vairiable is not welcomed.

What I would like is a super computer controled little wing and a gyro to fly the bike at an even down force. No nose dive ,no wheelie. Just little twitchy wings holding the bike perfectly flat

[VaFish]

I thought that wing on the back of my Ninja was to make it go faster.

[Racer x]

Speed comes from the engine power. Stability comes from the bodywork

[tgold]

Originally Posted by Racer x

It won't or does not work because motorcycle use three axes, up down and sideways. Down force becomes up force when the angle changes. So you have to much traction then start to fly all with the twist of the throttle.
Tiny computer controlled canard type wings are something I have given a lot of thought to.

What do you mean: "It won't or does not work"? It certainly does. That's why Ducati used them in the first place. The winglets on the front aid in reducing front end lift under acceleration and also provide increased d
ownforce during cornering. All of the other factories would not have followed Ducati's example if it were not an advantage. As a matter of fact, since the ban of external winglets factories are developing internal bodywork aerodynamics to help provide the same benefits as the winglets.

There is at least one potential drawback though. Front tire wear can be accelerated due to the increased grip due to the downforce created by the winglets while cornering.

[Racer x]

I will stand by it does not work. Maybe little bumps or something that does not create lift. But spoilers or real wings create problems. When I see things like the Ducati. I am interested to see if they are still there in five years. I'm probably wrong. But it will be interesting to see. Drag racing legend Don Garlet added winglets to his top fuel rail. It was there to distract the competition from real developments at the rear ending the car.

[Mohawk]

Originally Posted by tgold

There is at least one potential drawback though. Front tire wear can be accelerated due to the increased grip due to the downforce created by the winglets while cornering.

It is not possible for those winglets to produce down force in a corner. They certainly continue to produce a force, but as the bike is no longer upright & is relying on side grip in a corner, they become a liability, becuase they create MORE side trust, which is what the tyre is trying to conteract.

Some analysis of the Ducati winglets suggects that at very high speed they produce some downforce, but more importantly they produce a low pressure zone outside the fairing cooling air outlet, thus enhancing the cooling of the motor & a cool engine runs better than a hot one in racing.

[tgold]

Originally Posted by Racer x

I will stand by it does not work. Maybe little bumps or something that does not create lift. But spoilers or real wings create problems. When I see things like the Ducati. I am interested to see if they are still there in five years. I'm probably wrong. But it will be interesting to see. Drag racing legend Don Garlet added winglets to his top fuel rail. It was there to distract the competition from real developments at the rear ending the car.

So all of the factory teams didn't understand as much as you do and were using something that does not work? Right.

You won't see them in five years because they've been for banned "for safety reasons" in MotoGP starting in 2017.

[Racer x]

I don't meant to sound like a know it all. I'm sorry if I came off like that. But I do know a little about motorcycle aerodynamics and I don't think they are safe. And I don't think they are helpful in many forms of motorcycle racing. It's just my opinion. I won't change my mind on that. If the wings move and I mean move fast then they might work. And by work I mean. Don't create drag to slow you,down don't create lift to change traction coefficient. Don't cause a wheelie to become a blow over. Don't provide down force to change suspension caricteristics in a turn. If they don't do any of that and somehow produce good results. Like better lap times or higher speeds then my opinion will change.

[jkv45]

According to what I read about Ducati's wings, they were being used to lessen the need for traction control (to reduce power) to keep the front down while accelerating at high speeds. The Ducatis were consistently the fastest on the straights, possibly because they could put more power down sooner as they exited the corner onto the straight.

CW's Kevin Cameron on the subject - http://www.cycleworld.com/2016/03/07...meron-insights

[redonninrf]

Was listening to a race broadcast a few moths ago. The sportscasters were speculating one reason might be to increase turbulence and buffeting behind the bike making it harder for a trailing rider to draft close and pass.

[Ducati999]

Originally Posted by Racer x

I will stand by it does not work. Maybe little bumps or something that does not create lift. But spoilers or real wings create problems. When I see things like the Ducati. I am interested to see if they are still there in five years. I'm probably wrong. But it will be interesting to see. Drag racing legend Don Garlet added winglets to his top fuel rail. It was there to distract the competition from real developments at the rear ending the car.

@RacerX--I do not have the experience with racing you do and I don't want to start any argument over this subject but I have read a few things about the wings on Ducati's. They claim that the "Wings" produce a small amount of downforce at 200+MPH (Downforce is said to be minimal at lower speeds). With the current bodywork and high center of gravity on these bikes the wind resistance at higher speeds makes the bikes want to wheelie. The computer has to reduce power to keep the front down so the small amount of down Force the wings produce reduces the amount of power the "Anti-Wheelie" has to remove resulting in higher top speeds. As speed increases so does the wind resistance making the bike want to flip over backwards, the low amount of down force on the nose is enough to reduce (not eliminate) the need to reduce power to continue accelerating. Ducati's have posted the highest top speeds on tracks for nearly every GP race this year. They even posted higher top speeds than the F1 cars at COTA this season!

[jkv45]

Originally Posted by redonninrf

Was listening to a race broadcast a few moths ago. The sportscasters were speculating one reason might be to increase turbulence and buffeting behind the bike making it harder for a trailing rider to draft close and pass.

That would be the same as purposely creating drag, and would cost you top speed.

Reduced top speed was clearly not a factor for the Ducatis.

[MrAtom]

Originally Posted by VaFish

I thought that wing on the back of my Ninja was to make it go faster.

They're so you can pick 'em up for portability.

[Racer x]

Originally Posted by Ducati999

@RacerX--I do not have the experience with racing you do and I don't want to start any argument over this subject but I have read a few things about the wings on Ducati's. They claim that the "Wings" produce a small amount of downforce at 200+MPH (Downforce is said to be minimal at lower speeds). With the current bodywork and high center of gravity on these bikes the wind resistance at higher speeds makes the bikes want to wheelie. The computer has to reduce power to keep the front down so the small amount of down Force the wings produce reduces the amount of power the "Anti-Wheelie" has to remove resulting in higher top speeds. As speed increases so does the wind resistance making the bike want to flip over backwards, the low amount of down force on the nose is enough to reduce (not eliminate) the need to reduce power to continue accelerating. Ducati's have posted the highest top speeds on tracks for nearly every GP race this year. They even posted higher top speeds than the F1 cars at COTA this season!

That is interesting. No argument just discussing technology. If they have things working than that is a plus on the side of wings being useful . I know Ducati has a problem with pulling wheelies at high speed. We have a couple racing at Ohio. Getting proper gears made is one problem. They reach for the sky in forth gear. But high speed wheelies are always a problem for any bike.

Keep in mind motorcycle aerodynamics are still in its infancy. Going over 225 mph on a motorcycle is not been done regularly until recently. going 250 plus mph is only for Land speed racing. With computers and time we should see 225 on road racing bikes as a normal thing. . Aerodynamics is ultra critical over 200.

[choneofakind]

Originally Posted by Racer x

It won't or does not work because motorcycle use three axes, up down and sideways. Down force becomes up force when the angle changes. So you have to much traction then start to fly all with the twist of the throttle.

Think that statement through a little. What's the angle where downforce becomes lift?









90 degrees.

So if the bike is already leaned to 90 degrees, what's not touching the ground? The tires. Aka, the bike has already crashed. They will always create downforce on the bike, regardless of realistic lean angle. The trick is how that impacts side loading and/or keeping the line through a turn.

No matter what the angle of the bike, the wings will always produce force that is normal to the plane of the wing if the bike is moving forward. Because the wings are normal to the head tube of the bike, this means the wing will always produce force into the asphalt.

Friction between the tire and the asphalt is calculated by the normal force times the grip coefficient. Therefore, more force = more grip. Period. Like I said, there might be some oddities due to the fact that the bike leans and therefore the force normal to the ground will be some fraction as the lean angle increases. Additionally, the wings will produce some side loading as the lean angle increases. But there will always be some component pointing into the ground because motorcycles don't ride upside down!!!

Race team engineers wouldn't run them if they didn't work. They have SO MUCH data collected every time that bike leaves the pits. Data = validation for designs. If the wings didn't work, they would have been taken off the bike during preseason testing.

[adouglas]

Lots of imprecise language flying around in this thread.

Let's not assume anything.

If you have a fixed winglet and the bike wheelies, as soon as the angle of attack goes from negative (front wheel on the ground, wing pressing down) to positive (wheelie situation) then the wing is producing lift, not downforce.

I think that's what's being described, but I might be wrong.

Given that these bikes have electronic wheelie control, I imagine it'd be a trivial thing to prevent the front wheel from getting that far off the ground to begin with.

Lateral lean doesn't change wing performance, since the wing doesn't "know" where the ground is. All it sees is relative wind, which is governed by speed and pitch attitude, not roll. (The wings are too short to experience ground effect, even at extreme lean.)

So assuming the bike hasn't pitched nose-up enough to cause air to get under the wing and try to flip the bike over backwards, the force produced by the wing will always be parallel to the z (vertical) axis of the bike and will want to compress the suspension.

At lean, that means greater side loads AND greater downward loads, because the net force is the summation of those two vectors. Therefore a larger contact patch and more traction, assuming you're not already at the limit.

Since the wing-equipped bikes don't seem to be more prone to tucking the front, it would appear that the magnitude of downforce produced at typical cornering speeds is not sufficient to overload the front contact patch. And since the wing-festooned Ducs routinely out-drag everybody else, it would appear that the accompanying drag trade-off isn't a real handicap either.

So... it all comes back to the primary benefit being the ability to turn down the wheelie control and thereby get better drive off of the corners.

Aero is always a compromise. You're sacrificing one thing to gain an advantage elsewhere. In F1, for example, the cars that are fastest in a straight line are often the backmarkers. Their wings don't produce as much downforce, so therefore yield less drag and allow higher top speeds. But they don't stick as well in the corners, so the net effect is slower lap times even though the top speeds are greater.

[CycleCam303]

Hmm. Duh. In response to @choneofakind, another way to look at this is that downforce is still produced on banked ovals for cars. NASCAR races with angles up to 36 degrees. That's very steep and Indy cars deal with the same. They are still creating effective downforce.

So even with motorcycles and the lean angles they achieve, downforce is in play.

[CycleCam303]

Also, I want canards on my motorcycle. Because awesome.

[choneofakind]

Right... so Andrew is right that I assumed lean angle change, not pitch angle change. For that, I stand corrected and I apologize for my oversight.

That said though, look how much downward angle of attack the wings have. They're also probably an upside down foil shape... so even if your nose is pointing high enough to loop it, they're still making down force. They won't be making lift until the bike is already beyond the looping point of no return. Moot point.

But you raise an interesting point about the magnitude of all these aero effects. Clearly, they've not raised the CoD to the point where F1 cars have. An F1 car has a drag coefficient of 1+!!!! But they're glued to the track in turns as long as they keep speed. I bet the transition to driving one would be brutal for someone who hasn't spend tons of time racing an "aero car" as I've heard them called. Corner speeds.


Cam, slightly different scenario you've brought up. NASCAR uses banked turns so that the car is always normal to the driving surface. Bikes lean relative to the driving surface, cars do not.

[Racer x]

OK let me back pedal my statement. Wings may do something at some point that is bennifical. I don't like them because I think they will push toward the tires when you are in a turn. Increasing lateral load on the tire patch area. And when the angle goes positive it lifts the front end. At 200 mph things are happening to fast for people to react.

Another thing is vaireables. I really want consistency on a motorcycle at 200 mph. Let's not forget weather and wind conditions. 15 mph headwind is 30 mph faster than 200 in a tail wind. That is a big difference when talking about a wing.

Edit... How far do Moto GP riders lean? I mean with or without wings. They look like they are really leaned over sometime.

One thing about race teams. They do things for a lot of reasons. You show up with a wing and no one else has one. The others teams now are wishing they had some. Even if they are to small to do anything. It's a mental game sometimes.

[AchyGrappler]

I for one am torn. I understand and agree that banning the winglets is probably best for the sake of the race and sport of motorcycle road racing as only the big factories would be able to invest in them creating a "have" versus "have not" situation on the track that would ruin the race viewing experience.

On the other hand as a Mechanical Engineer that loves the technology of motorcycles as much as the sport of riding motorcycles I am disappointed that yet another advancement of the technology is being prevented from continuing forward.

It will be interesting to see how the Ducatis do without the wings as I think it will hurt them the most.

[Mohawk]

Originally Posted by CycleCam303

Hmm. Duh. In response to @choneofakind, another way to look at this is that downforce is still produced on banked ovals for cars. NASCAR races with angles up to 36 degrees. That's very steep and Indy cars deal with the same. They are still creating effective downforce.

So even with motorcycles and the lean angles they achieve, downforce is in play.

I think you'll find that NASCARs produce their bank angle because the GROUND is banked. The whole point of a banked turn is to reduce SIDE LOAD on the tyres, thus allowing the car to maintain speed in the corner. A NASCAR is as fast as an Indy car, but put a NASCAR on the infield flat turns & an Indy car will piss all over them. NASCAR is a straight line vehicle that relies on the banks to make it run high corner speed, hence the lack of wings for downforce. They start to fly because they exceed the banks maximum speed & when they exceed the limited down force over the car body & the mechanical grip of the tyres they lift & hit the wall.

An Indy car can run the oval corner with less wing as the bank makes up for some of it, but if they keep full wing & adjust the suspension to compensate for the increased G they can go even faster. The problem is the aerodynamics act straight down to the ground in a car regardless of the angle of the ground.

If you imagine that the whole purpose of a wing is to make a vehicle appear heavier than it is whilst in motion, thus pushing the tyres harder into the floor. So when upright on a bike it's the same, but because a bike changes its angle to gravity to make a turn, which creates a fake gravity force straight down towards the tyres, NOT the ground, a wing on a bike in a corner will make the tyres work harder. Easy way to try this, is take your bike to max lean at max speed, now add 50kg of lead around your waist, so as to keep the C-of-G in the same place & try the same corner again. One of two things will happen, you will crash if attempted at the same speed, or you WILL go slower due to lack of side grip.

That's why Racer-X wants moving &/or stowable wings, more or less down force/drag when needed. That is the concept of F1 DRS, at speed you need less wing for the same effect, hence car with movable wing section open goes faster than one in front with fixed wing load.

[adouglas]

Originally Posted by Mohawk

because a bike changes its angle to gravity to make a turn, which creates a fake gravity force straight down towards the tyres, NOT the ground, a wing on a bike in a corner will make the tyres work harder.

Half right... yes it will make the tires work harder, but it WILL create more force toward the ground because the "fake gravity force" (i.e. downforce produced by the wing) has two components, vertical and horizontal.

The red arrow here is downforce. The vertical component is added to gravity, so yeah... it is producing a force towards the ground.

Originally Posted by Mohawk

Easy way to try this, is take your bike to max lean at max speed, now add 50kg of lead around your waist, so as to keep the C-of-G in the same place & try the same corner again. One of two things will happen, you will crash if attempted at the same speed, or you WILL go slower due to lack of side grip.

Max speed assumes that you're at the limit of traction. But that doesn't necessarily mean you're actually at the limit of the tire. We know that increasing the size of the contact patch increases traction. That's why we squeeze the brakes instead of grabbing... to press the tire down and increase the contact patch. Adding weight will do the same thing, up to a point. Then max cornering speed is higher because there's more rubber on the road, all else being equal.... however, since MotoGP bikes lean at ~60 degrees, it seems likely that the tire would in fact give up because the horizontal component of the load (which does nothing to increase the size of the contact patch) would be greater than the vertical component.

Easier to visualize this if you think about it in terms of an F1 car. That brutal cornering traction is due to the tire getting shoved down into the pavement: bigger contact patch. Take the wing off the car and max cornering speed is much lower than with the wing, right? The tires give up at a lower speed, but they're far from their ultimate physical limit. So you add downforce and hey presto, faster cornering.

Adding mass would do the same thing with the contact patch, but the limits would be different because of inertia (on a car, anyway... interesting thought experiment if applied to a bike, because on a bike what matters is the net force; the horizontal and vertical components cannot be separated the way they are on a car). The nice thing about aero downforce is that it doesn't add mass, but it does add "weight."

All rather academic, because it's been said that the point of wings isn't to improve cornering, it's to keep the nose down when accelerating.

[Ducati999]

The information I expressed above was from Cycle World either the July or August Issue. They don't work for Ducati but I think they made a really strong case for their explanation. I will see if I can find the article once I get home and post a link or at least the month and page number so you can decide for yourself.

[jkv45]

Originally Posted by Ducati999

The information I expressed above was from Cycle World either the July or August Issue. They don't work for Ducati but I think they made a really strong case for their explanation. I will see if I can find the article once I get home and post a link or at least the month and page number so you can decide for yourself.

Link to the CW article is in post #14

[Mohawk]

I think we will have to agree to disagree. Force towards the tyre on a corner is what leads to the maximum speed due to the adhesion of said tyre. If you increase that then you will overload the tyre FACT. A fixed wing adds zero force directly down when banked, ask any pilot. PS I fly too. Just watch the Ducati's corner performance to check this.

[adouglas]

Fair enough.

PS I'm a pilot too. Was an aviation journalist for ten years in an earlier life.

As my 7th grade science teacher used to say... look at da vectors. Seems plain to me, but whatever. Didn't say the wing adds force directly down and nothing but. Said that there IS a vertical component to the force, which by definition is towards the ground. This cannot be separated from the horizontal component, any more than you can in an airplane.

If there is no downward component to the resultant force, then it must by definition be entirely horizontal. Which means the wing would somehow be producing force that is not perpendicular to the wing. Which is not what's happening.

Sure the tire will overload IF it's at its limit and you add more force. Happens all the time, when riders tuck the front. But of it's not at the limit, then no. Proof? Take a wheel (a bicycle wheel will do) and lean it over. Push a bit. Now push a bit harder. Did the additional push cause the tire to slide? If it was at the limit before that second push, yes. If not, no. Which means there was enough extra traction to absorb the additional force.

Increase contact patch size and you increase adhesion. Available traction is therefore NOT fixed. I am in no way saying there isn't a limit. I am saying that the limit is variable and is dependent on loading, among many other things (e.g. tire condition, road surface, etc.).

Don't take my word for it. Visual demonstration of how contact patch and adhesion are related is in this video. Start at about 2:14 and watch for about a minute. Right about at 3:00 you can see Nick Ienatcsh lean hard (really hard) on a tire that's leaned over and it doesn't slip. Then with the tire at the same angle but unloaded he whacks it with his palm and it breaks loose instantly. The difference is that in the first case, he's squished the tire and given it a big contact patch. In the second, the unloaded tire's contact patch is tiny so there isn't much traction available.

Link to original page on YouTube.

[choneofakind]

Originally Posted by Mohawk

Easy way to try this, is take your bike to max lean at max speed, now add 50kg of lead around your waist, so as to keep the C-of-G in the same place & try the same corner again.

Not the same thing at all as down force. Draw the free body diagram for each scenario.

[choneofakind]

Originally Posted by Mohawk

I think we will have to agree to disagree. Force towards the tyre on a corner is what leads to the maximum speed due to the adhesion of said tyre. If you increase that then you will overload the tyre FACT. A fixed wing adds zero force directly down when banked, ask any pilot. PS I fly too. Just watch the Ducati's corner performance to check this.

...the hell kind of physics classes have you taken?

[Motofool]

Please, consider these:

1) The drag force caused by the projected frontal area of the bike and rider times its coefficient of drag pivots on the rear contact patch, which transfers weight on that patch and takes it away from the front contact patch.

2) That transfer of weight loads the rear suspension and unloads the front suspension (away from the ideal working ranges) and increases the trail of the steering (making steering heavier and the risk of tank slappers higher).

3) The above drag force is directly proportional to the square of the speed of the bike.
That means that the force is 2 times greater at 140 mph than it is at 100 mph.

4) The lift (negative in this case) generated by an airfoil is greater than the induced drag, for the useful angles of attack (angle between the airflow and a line between the leading and trailing edges).

5) The wings are not effective for any angle of attack; the lift is greatly diminished and the drag is exaggerated above 9 or 10 degrees.

6) For a useful angle of attack the above lift and drag forces are, again, directly proportional to the square of the speed of the bike.
That means that the forces are 2 times greater at 140 mph than they are at 100 mph.

[JohnnyBravo]

I ain't got nary clue what y'all babblin on abouts but all them colors, fancy werds, and pics sure do look an sound purdy... They gonna make folks stop drinkin redbull too?

P.S. Will the winner of the measuring contest do a victory lap so I know who was the least wrong

[Ducati999]

Originally Posted by jkv45

Link to the CW article is in post #14

Thank you, Sorry I missed the link. I found the second article I reffered to in the above post. Sports rider August 2016. They list that the Ducati GP bikes had the highest top speeds in nearly every practice session especially at COTA. Most tracks all the Ducs were the fastest (highest top speed not lap times) and scored 1-6 or 7 but did not lap as well. Not saying the "wings" made this possible but they would not use them if they did not serve some purpose. So far we have had proposals that they could be for #1 reducing the need for wheelie control at higher speeds, #2 added corner grip, #3 mind games, #4 added turbulence to reduce slipstream passing

Since Yamaha and Honda are also trying them out, I believe there must be some (possibly only perceived) advantage. Lorenzo liked them but Rossi said he did not feel anything different. Since they are now banned for the next season maybe they will give up some info on what the concept behind them really was if any. My 999 has "wings on the fairings (different plane of force) but the full Superbike racers did not always use them. The Kawasaki H2 has wings also and I think Kawasaki's design had more purpose than just to look cool.

[taz]

Originally Posted by Ducati999

The Kawasaki H2 has wings also and I think Kawasaki's design had more purpose than just to look cool.

yup for the HIGHER SPEEDS it can hit to help the front stay down.

[tgold]

Originally Posted by adouglas

Half right... yes it will make the tires work harder, but it WILL create more force toward the ground because the "fake gravity force" (i.e. downforce produced by the wing) has two components, vertical and horizontal.

The red arrow here is downforce. The vertical component is added to gravity, so yeah... it is producing a force towards the ground.





Max speed assumes that you're at the limit of traction. But that doesn't necessarily mean you're actually at the limit of the tire. We know that increasing the size of the contact patch increases traction. That's why we squeeze the brakes instead of grabbing... to press the tire down and increase the contact patch. Adding weight will do the same thing, up to a point. Then max cornering speed is higher because there's more rubber on the road, all else being equal.... however, since MotoGP bikes lean at ~60 degrees, it seems likely that the tire would in fact give up because the horizontal component of the load (which does nothing to increase the size of the contact patch) would be greater than the vertical component.

Easier to visualize this if you think about it in terms of an F1 car. That brutal cornering traction is due to the tire getting shoved down into the pavement: bigger contact patch. Take the wing off the car and max cornering speed is much lower than with the wing, right? The tires give up at a lower speed, but they're far from their ultimate physical limit. So you add downforce and hey presto, faster cornering.

Adding mass would do the same thing with the contact patch, but the limits would be different because of inertia (on a car, anyway... interesting thought experiment if applied to a bike, because on a bike what matters is the net force; the horizontal and vertical components cannot be separated the way they are on a car). The nice thing about aero downforce is that it doesn't add mass, but it does add "weight."

All rather academic, because it's been said that the point of wings isn't to improve cornering, it's to keep the nose down when accelerating.

I'm not sure where you got the idea that the only point of the wings was to keep the nose down during acceleration. It is both acceleration and cornering as every MotoGP rider accelerates out of evrry corner. (unless they crash!) I was watching the MotoGP test at Valencia 15 minutes ago and a rider was commenting on how the wings help give better front end feel. There is a lot to be said about that since rider confidence goes up as they can better feel what the front end is doing. When rider confidence goes up riders go faster. That is something impossible to quantify by talking about vectors and downforce, etc, but it is nonetheless true.

[Mohawk]

I think you'll find its the placebo effect rather than reality, those tiny winglets can not produce any useful amount of frorce at the speeds in most of the corners the riders have to negotiate, as witnessed, by the same bike with or without winlets (Lorenzo/Rossi or Marqez/Danny) having near identical lap times.

As to those who say the factory knows what they are doing, well if that was the case there would be no hope for the world. Bike factories have never been big on aerodynamics & almost certainly do NOT have very experienced aerodynamacists working for them. They could hire guys in, but those guys would have NO experience of aero on bikes, they are signifficantly different from any other vehicles ! So until Ducati popped some on their bike, NO one had any experience in this field, other than a few experimenters, who rarely had access to the resources required to quantify their result scientifically. People always assume that big companies put lots of money & effort into everything, but having worked for soem huge companies, you would be stunned at their attitude to getting things right sometimes ! Either way they are banned next year & were mute this year, as bikes with wings did no better than bikes without.