What Causes the Rear of the Car to Sway Left and Right When the Rear Wheels Go Over Bumpy Roads?

[MacMariana]

The reasons for the rear of the car swaying left and right when the rear wheels go over bumpy roads are: 1. Wheel undulation (up and down bouncing) causes the wheels to deflect upward in an arc. 2. This arc-shaped movement changes the distance between the tie rods connected to the wheel knuckles and those connected to the vehicle (the front tie rods are connected to the steering gear, while the rear tie rods are connected to the chassis). The solutions to prevent the rear of the car from swaying left and right when the rear wheels go over bumpy roads are: 1. The position and length of the arms can be designed so that the tie rods move toward the wheels in a similar arc when the wheels deflect, thereby minimizing the impact of undulation steering. 2. All components are aligned with the central point (dashed line). When the wheels deflect, the arms all move in similar arcs (red line), and the distance between the tie rods and the wheels remains completely unchanged.