The torsion bar suspension, is something being used in the automobile industry for long time. However it is a technique you may have not seen reproduced in a LEGO model before.
"A torsion bar suspension... is a general term for any vehicle suspension that uses a torsion bar as its main weight bearing spring. One end of a long metal bar is attached firmly to the vehicle chassis; the opposite end terminates in a lever, mounted perpendicular to the bar, that is attached to a suspension arm, spindle or the axle. Vertical motion of the wheel causes the bar to twist around its axis and is resisted by the bar's torsion resistance. The effective spring rate of the bar is determined by its length, diameter and material."
Julien Florent (Yurikostar) presented his solution, during the latest FreeLUG meeting, applied into one automobile chassis.
Simultaneously reliable and simple.
Thanks for the tip, Didier.