I need help deriving a formula to describe the effect to toe in on speed

At first I thought it might just be a simple equation using $\displaystyle cos{\theta}$ where $\displaystyle {\theta}$ is the degrees of toe in.

http://i551.photobucket.com/albums/i...22/toein-1.jpg

But thats not it. I need to take into account rolling friction.

The equation for rolling resistance is

$\displaystyle F=cN$

F is the force of rolling friction

c is the rolling resistance coefficient

N is the normal force.

I think it might be along the lines of

F(final) = $\displaystyle Fcos{\theta} - cN$

Here is a pic of what I'm talking about:

http://i551.photobucket.com/albums/i...untitled-2.jpg

Then I need to relate Force to Velocity.

Any ideas?

-Tony