When looking at the tire from the front and rear direction of the car, the kingpin axis inclines inward to the vehicle body. This angle is called the kingpin inclination angle. When the wheel rotates around the kingpin, the lowest point of the wheel will sink below the road surface. But in fact, the lower edge of the wheel cannot sink below the road surface. Instead, the steering wheel and the entire front part of the car will be lifted up a corresponding height. In this way, the gravity of the car itself has the effect of returning the steering wheel to its original middle position. Therefore, the steering wheel is easy to reset.
In addition, the kingpin inclination angle also reduces the distance from the intersection of the kingpin axis and the road surface to the intersection of the wheel center plane and the ground. Thus, it reduces the force that the driver applies to the steering wheel during steering, making steering operation easy. At the same time, it can also reduce the impact force transmitted from the steering wheel to the steering wheel. However, the kingpin inclination angle should not be too large either. Otherwise, it will accelerate tire wear.
