Gathering: when stationary, the front wheels on a Renault are narrower at the rear than at the front. They roll as if in different directions from each other. The fact that the rear parts of the wheels are located closer than the front allows you to balance the drive forces that tend to bring the wheels together.
When cornering, this form of wheel arrangement works by means of a trapezoidal steering system in such a way that the wheel moving along the inner curve of the turn turns more than the outer wheel. This facilitates cornering by virtue of the fact that when cornering, the wheel moving on the inside curve travels a shorter distance than the wheel moving on the outside curve.
Front camber angle
This is what they call the installation of the front wheels at a slight angle - at the top in the wheel arch of the Renault 19, they are located further apart than at the bottom on the ground. In the language of specialists, this is called «positive» collapse. Camber reduces the impact of road bumps on the controls and also reduces steering effort and wheel friction on the ground.
The angle of the transverse inclination of the axis of the kingpin: this concept refers to the collapse. The term refers to a slight tilt of the rotary axis so that when the steering wheel is turned, the entire suspension of the wheel is turned. Both rotary axes have a smaller interval above than below relative to each other. The camber and caster of the king pin also prevent wheel vibration. In addition, they create wheel turn and provide «reaction moment», thanks to which the steering wheel returns to its original position after cornering.
Longitudinal inclination of the kingpin axis: this term is understood as the installation of a controlled axle at an angle to the longitudinal direction of movement of the vehicle. This position will stabilize the straight-line coasting and prevent the front wheels from swaying. In addition, it helps to return the steering wheel to its original position after cornering.
To explain the meaning of wheel alignment terms, we provide this figure:
A - Camber angle of the front wheels;
B - Longitudinal inclination of the kingpin axis;
The difference between X and Y is the toe of the front wheels.