Longitudinal and lateral forces depend on slip ratio (slip) and slip angle. Camber thrust adds lateral force if camber angle is not zero.
Longitudinal force depends on slip ratio. XMR uses Sakai slip definition:
Traction Slip = V * cos (A) / w*R – 1
Braking Slip = 1 – (w*R)/(V*cos(A))
V – speed of the tire over the roadway
A – slip angle of the tire.
w – angular velocity of the tire
R – effective radius of the tire
Slip angle is an angle between a rolling tire’s direction and the direction of the tire heading.
You can see that Traction Slip < 0 and Braking Slip > 0.
Slip is limited by [-1..1]
For example, traction slip is -0.5 when the tire spinning (2X free rolling).
-1 Slip when tire spinning (infinite).
At this picture you can see a typical longitudinal forces (tractive or braking) diagram when a slip angle is zero and tire load is equal to 4 kN.
You can see when the tire has the maximum tractive and braking forces. Tractive force at -1 Slip is less than Tractive force at -0.5 Slip. The same behavior for braking forces.
On the picture below you can see a typical lateral force diagram when a slip is zero and tire load is equal to 4 kN.
You can see that lateral force is max at 7 degree of the slip angle. Lateral force is decreasing with the increasing of the slip angle. So you will have less grip at large slip angle.
And a short video to see slip and slip angle