Quote:
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.
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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.
Quote:
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.
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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.