Multi-link is the quintessential suspension system; torsion beam is light and competent

Are cars with multi-link rear suspension dynamically superior to those with torsion beams?

Multi-link suspension systems are more complicated than torsion beam suspensions.

As its name suggests, there are several separate linkages, usually five in the overall assembly of the multi-link arrangement.

While this makes it possible for each wheel to move independently of the others on the same axle, the real benefit is in the greater degree of freedom to design the way each wheel moves under different load conditions, terrains and cornering speeds to achieve the optimum geometry.

The resulting benefits from such a set-up are enough to prompt carmakers to use the technology on both the front and rear axles of the car.

Compared with the relatively simpler Macpherson struts, and especially the rear torsion beam designs, the multi-link systems are more complex to design due to the higher level of precision necessary for the various mounting points on the undercarriage. Having more components also leads to higher material costs.

Multi-link suspensions also take up more space. This can mean sacrificing a bit of cabin space as well.

The torsion beam rear axle, on the other hand, was made popular by the first-generation Volkswagen Golf in 1974, a car that was lauded for its ride and handling characteristics. This was despite the torsion beam layout being rather rudimentary.

With very few components required, the entire assembly was light and compact, barely encroaching into the rear luggage or passenger compartment. This was an important consideration in a compact hatchback like the first-generation Golf.

A transverse beam connects the left and right suspension arms. The truly interesting aspect of its design is that the beam can twist, acting like torsion spring. If you hold a steel ruler at the two ends and twist, you will get an idea of what the spring effect is like.

While the torsion beam provides the roll stiffness, it also causes some degree of camber and toe angle changes, benefiting ride and handling. The Golf’s legendary handling bears testimony to the genius of the torsion beam rear axle.

The multi-link continues to be the quintessential suspension system, but the torsion beam maintains its place in the suspension-design bible for being competent, adaptable, compact and relatively inexpensive.