Basic Purpose

• The purpose of any rear suspension is to use the force of the springs to push the wheels to the road and to control their movement over imperfections in the road.
  
  

Load Suspension

• Modern leaf-spring suspensions are almost always found on heavy trucks. This type is generally considered the best for bearing a heavy load, but suspensions using coil springs (as in most cars) allow for more range of up-and-down suspension movement.
  
  

Bound Traction

• The dampers and springs in most suspensions are usually designed to compress as slowly as possible, which keeps the tires in contact with the road surface as much as possible.
  
  

Triangulation

• Many coil spring-suspended cars have triangulated four-link (TFL) suspensions. TFLs utilize control arms set at an angle parallel to the ground, which prevents side-to-side axle movement.
  
  

Load Transfer

• Many rear suspensions have long lower arms that connect around the center of the frame. This allows the suspension to "lift" the nose of the car under acceleration to shift more traction-enhancing weight to the rear.