this section examines basic principles of light vehicle suspension systems the suspension system isolates the body from road shocks and vibrations which would otherwise be transfer to the passengers and low it also must keep the tires in contact with the road when a tire hits an obstruction there is a reaction force the size of this reaction force depends on the unsprung mass of each wheel assembly the sprung mass is that part of the vehicle supported by the springs such as the body the frame the engine and associated parts unsprung mass includes the components that follow the road contours such as wheels tires brake assemblies and any part of the steering and suspension not supported by the springs vehicle ride and handling can be improved by keeping unsprung mass as low as possible when large and heavy wheel assemblies encounter a bump or pothole