14 September 2018

Steering axis inclination | Definition | Purpose | Effect

Definition of Steering axis or Kingpin inclination : 

The inclination of the kingpin from vertical is called the king inclination or steering axis inclination. 

Steering axis inclination causes both front wheels to gain positive camber because they steer away from the centre.

In modern cars where the kingpin has been replaced by the ball joints, this term has also been termed as steering axis inclination. It is defined as the inclination of the ball joint axis from the steering vertical axis. The steering axis is an imaginary line drawn through the lower and the upper steering pivot pins. 

Steering axis inclination is set by the dimensions of the upright and therefore no adjustable once it defined. 

Purpose of steering axis inclination :

To determine vehicle stability while moving on the straight road. 

Steering axis inclination

Effect of steering axis inclination :

Kingpin inclination also called steering axis inclination helps the straight-ahead recovery, thus providing directional stability. When the vehicle takes a turn, the inclination of the kingpin causes the vehicle body to move up in relation to the wheels. So when the steering wheel is left after the turn is completed, the weight of the vehicle tends to return the wheels to the straight-ahead position. 

Amount of inclination is about 7 to 8 degrees. However, the exact amount is decided considering the wheel rack value. It is kept below 8 since too much inclination cause a lot rising of the front axle when steering.