# camber

Left wheel (viewed from behind) with negative camber. The angle is exaggerated for clarity.
Camber (wheel in the foreground positive, wheel in the background negative)

Wheel camber or camber is a term used in chassis technology . The angle between the center plane of the wheel and a vertical line to the roadway is called a camber . A distinction is made between a fall in relation to the roadway and a fall in relation to the vehicle. In the vehicle-mounted system , the camber is positive if the top of the wheel is inclined outwards.

The fall of the road is to ISO  8855 in the tires - coordinate system specified. The x-axis is the line of intersection between the roadway and the wheel center plane and points forward, the z-axis points upwards perpendicular to the road. A rotation about the x-axis in contrast clockwise ( mathematically positive ) defines the positive camber angle.

A slightly negative camber of all wheels is common in passenger cars ("stand there with your legs apart", see illustration), as it causes a higher maximum cornering force in curves.

With independent wheel suspensions - depending on the axle principle and the kinematics of the axle - the camber changes over the spring travel . In contrast, with rigid axles the camber to the road remains approximately constant when cornering. The lintel in the construction position is also known as the basic lintel .

## purpose

Cornering forces can only arise with rolling tires if there is a slip angle and / or camber. In the case of two-wheelers , the lateral force is mainly generated by falling (by “leaning into” the curve), while in the case of two-wheeled vehicles, it is mainly generated by slip angles. A fall results in a favorable stress distribution of the tread particles in the tire contact area . For cars basic camber and camber change can be used for partial compensation of the camber angle to the road, extending at the curve outer wheel through the Wank tilt results in the vehicle.

In cars, a negative camber of all wheels (“standing with your legs apart”) causes a higher maximum cornering force in curves. The pressure distribution in the contact area of ​​the tire becomes more even, as the "belt fall" can be compensated. Furthermore, a negative camber results in a smaller slip angle requirement and is often used in motor racing . But sports suspensions for higher-powered vehicles, which are available as an option , usually have a stronger negative camber. At high driving speeds, however, too great a negative fall has a negative effect on the service life and load-bearing capacity of the tires, so values ​​over two degrees are not recommended for cars.

The following rules of thumb apply in motor racing :

1. The more cornering force the tire type can build up, the more negative camber makes sense.
2. The camber setting is ideal when the inside of the tire is slightly warmer than the outside.

The more the camber deviates from the vertical, the more a tire will be worn on the more loaded side when driving straight ahead, with a negative camber this is the inside. This one-sided wear is undesirable in everyday use because it reduces the service life of the tire. It is usually the result of an accident and should be checked in the workshop when adjusting the toe and camber .

## Special cases

Heavily cambered , narrow roadways cause a significant fall towards the wheels. So that a transport vehicle or robot can drive well in a sewer channel, the camber on the vehicle is set so strongly negative that the wheels stand up on the driving surface without a camber, i.e. at right angles.