Bump steer

When an uneven road surface causes a vehicle to steer or lose directional stability, this is called "bump steer". At the front, bump steer is associated with the tie-rod and linkage-arm relationship. It is caused by the method of locating the rear suspension, the type of rear suspension, and the geometry of the various linkages. In race cars, bump steer is designed out of the suspension so that the handling is as precise as possible. In most cars it is present to some degree. In fact, it can be useful to allow engineers to design a small amount of understeer or oversteer into the chassis.