What Are The Pros And Cons Of A Torsion Beam Suspension?

Very like muscles and tendons working together to soak up shock for the human body, or how trainers cushion impact with each stride, a automobile’s suspension combines fastidiously designed components to tame the world’s imperfect streets and highways within the name of safety, comfort, and performance. Engineers have give you several approaches to suspension design through the years, each with different cost, complexity, and packaging considerations. These factored directly into why Mazda elected to utilize a torsion beam rear suspension when it redesigned the present Mazda 3 platform in 2019.

No matter where a vehicle shall be driven, getting suspension settings right is a vital mixture of art and science that starts with selecting what form of suspension design to make use of. Some vehicles, like Jeeps, are famous for being engineered to overcome the roughest terrain, while Formula One racing suspensions are designed to soundly extract every last ounce of speed throughout the limits of drivability on the racetrack. Torsion beams, though less sexy than their sophisticated multi-link counterparts, are simpler rear suspension designs that may offer lower weight and costs, and release beneficial passenger or cargo space — in exchange for potential dips in ride tuning and customization.

Murphy’s Law says that whatever can go flawed, will go flawed. Murphy would probably dig torsion beams for his or her simplicity. Where the rear wheel hub and brake assembly meet the automobile, a standard multi-link suspension setup incorporates a combination of parts, from upper and lower control arms, to shocks, springs, and connecting rods, on all sides. That is 10 components — plus an anti-roll bar that runs between the wheels for lateral stability.

In contrast, as pictured above, a torsion beam mainly has five major components — total — including an H-shaped frame to mount the springs and shocks, and trailing arms with bushings to hitch as much as the chassis. The beam part spanning that H gives the torsion beam its name, and effectively fuses the best and left sides of the suspension together.

In our age of other facts, let’s decide to agree that five parts is lower than 10 parts. From a reliability perspective, that is 50% fewer potential failure points to fret about and maintain — not to say reduced production complexity, lower costs, and fewer parts to tune and optimize for reasonably enjoyable and protected driving.

The compact packaging also helps release sweet interior volume for passengers and cargo. Torsion beams set the assembly comparatively lower within the chassis, and push the springs and shocks further out to the perimeters of the automobile — and which means more interior space for golf clubs, child seats, pets, and large box runs.

Tuning a suspension’s complex symphony of parts to our liking is considered one of our readers’ favorite automobile mods. All that complicated joinery in a multi-link setup — with so many variables in springs, bushings, shocks, adjustable end links, and stabilizer bars — lets each wheel move by itself, and lends itself to a number of modifications that may radically alter a suspension’s geometry and performance. It is a (potentially expensive) playground for personalization that torsion beams cannot match.

With a torsion beam setup, suspension tuning options are just about all the way down to the fundamentals: bushings, springs and shocks. This modification constraint may liberate or frustrate, depending in your perspective. As much as enthusiasts like to geek out over lowering springs or the difference between shocks and struts, we are able to only go thus far, because we will not change that factory-installed torsion beam spanning the automobile’s rear. Hence, the best and left wheel actions are never fully independent.

That does not imply torsion beam suspensions cannot yield track stars. Volkswagen ran them for ages on Golf GTIs, also referred to as the good granddaddy of hot hatches. Nor does it mean that ride harshness is the rule with torsion beams; as Mazda’s torsion beam work on the recent 3 shows, factory engineering wizardry can result in an ideal ride. Ultimately, then, the most important con of torsion beams is tied as to if you propose to customize your automobile’s performance, and the way much standard cushioning you think about customary. If it is a cushy air ride you are after, it’s possible you’ll want to examine out the professionals and cons of air suspension.