geometry serving to dynamically change the king pin axis angle relative to the road surface to improve tracking of the wheels during active suspension operation in response to variations in the road surface the upper link of the suspension is a fixed length in the suspensions inc system the suspension geometry is shown for the suspensions inc system where fig2 a illustrates the active mode while fig2 b shows the position of the elements when the suspension is lifted and inactive in operation as those of ordinary skill in the art will readily recognize the suspensions inc system operates as a trailing or leading quadrilateral link sometimes referred to as a parallelogram link despite the fact that the linkage is almost never a true parallelogram in modern usage the upper link of the quadrilateral beam 50 is shorter than the lower link in addition the lower link 30 is provided with a pivot 32 articulation about the lower link medial pivot 32 occurs when deflection is caused by the wheel passing over a bump in addition to deflection about frame mounted pivot 24 as the air bag 27 is compressed the wheel set is mounted on the axle assembly 40 at the terminal end of lower link 30 and includes a king pin a stub axle set into the live axle beam 42 with wheel bearings on which is mounted a wheel and tire the wheel set is also normally equipped with a brake.