In this wheels are mounted rigidly on the half axles, which are pivoted on their ends to the chassis number at the middle of the car. The main disadvantage of this system is that up and down movement of the wheel causes the camber angle to vary. Besides, during cornering, the car is lifted due to so-called jacking effect which produces positive camber on the outside wheel, which is more loaded. The result is a sudden loss in traction. These axles also have a high roll centre and a short swing arm length, both of which are undesirable. Such axles have been used on a few cars, although usually on the rear rather than the front.