The roll center of a vehicle is the point at which the vehicle body is said to rotate around when cornering. The location of the roll center is solely dictated by the suspension geometry. The significance of the roll center can only be appreciated when the vehicles center of mass is also considered. If there is a difference between the position of the center of mass and the roll center a “moment arm” is created. When the vehicle experiences angular acceleration due to cornering the size of the moment arm, combined with the stiffness of the springs and roll bars (sway bars in some parts of the world) dictate how much the vehicle will roll while cornering. This has other effects too such as weight transfer.

Weight transfer is of critical importance for vehicle stability in vehicle such as SUV’s. In high performance applications weight transfer is sought to be limited as a tyres performance is directly affected by the amount of load that it has to transmit.

The roll center of the vehicle can be found by following basic geometrical procedures when the vehicle is static. However, when the vehicle rolls the roll centers migrate. It is this movement of roll centers that vehicle dynamisists seek to control and in most cases limit. The rapid movement of roll centers when the system experiences small displacements usually leads to an instability problems with the vehicle.