Rotational speed of tires are not calculated with loaded radius. They are iterated by solver in static equilibrium process. For example, in a straight line event, you should be able to see multiple static simulations in the .msg file. Basically, Adams first settles down the vehicle on the road profile and find equilibrium. Tire rotational speed is not calculated yet during this phase. Then, Adams calls a VARSUB to calculates the 'virtual' tire rotational speed. Solver tries to get equilibrium, thus tries to reduce all accelerations to zero. That is used to get longitudinal forces on the tires as low as possible, and this happens at the correct rotational speed.

There are 2 types of tire radius,

• Loaded radius, this is the distance in between the wheel center and the road. In general, Adams use tire vertical stiffness to calculate loaded radius.
• Effective rolling radius, this is a 'virtual' radius, defined as Reff = vehicle speed/rotational speed.