Torsion Bar suspenuion

Chrysler in the '60s had a super simple suspensions system using torsion bars.

Why did thry stop using such a neat idea…???

Not sure, but it’s probably a combination of cost and weight. And it just replaced the coild spring, not all that much simpler. But it was nice being able to adjust the ride height.

I wonder if carbon fiber would work.

It was nice for drag racing …helped keep the fronon the turf.

I’m sure it has as much to do with “packaging” as anything. The truck (2wd Toy PUs) I’ve had with them were RWD. I wonder if it has more to do with that. I have a trailer with it and it’s self dampening; so definitely has it’s advantages.

Since the reaction to a twist… the wheel bounce is responded to more rapidly??

Fun fact - coil springs also twist just like a torsion spring, just, well, coiled up. They aren’t bent, they twist.

“Old” VW Beetles Used Leaf Torsion Bars In Front And Solid Torsion Bars In Back. Looking At A Bug You Wouldn’t Even Know It Had A Sprung Suspension.

I believe when Ferdinand Porsche designed the Volkswagen Type I (People’s Car) for Hitler, the simplicity, ruggedness, and especially the compact nature of torsions bars is why he chose them.


I think some vehicles still use torsion bars, I know Ford Ranger 4x4s did around 2000 and I think they still do.

My 02 GMC Sierra 4WD has torsion bars.

I remember driving a 1957 Plymouth with the torsion bar suspension when this car was introduced. It didn’t lean on corners and seemed to ride very well. The Chrysler line with this suspension caused quite a stir when it was introduced.
We also thought that the VW rode quite well in the late 1950’s. I’m not certain, but the Morris Minor of this period may have also had torsion bar suspension.

I think latr model Chevy 4x4 trucks use torsion bars!

Some will break and the results are more catastrophic, perhaps not high enough on the safety ladder for a critical component. Still very common on pickups but they go more with truck suspensions (load bearing lower ball joint) and we see the Mcphearson strut in more common use on passenger cars

“The main advantages of torsion bar suspension are durability, easy adjustability of ride height, and small profile along the width of the vehicle. It takes up less of the vehicle’s interior volume compared to coil springs. A disadvantage is that torsion bars, unlike coil springs, usually cannot provide a progressive spring rate.”

In these comments from “WiKi” and comparing the vehicles/trailer I’ve had with them, it seems to coincide. In the trailer I have, the bar is part of the axle and supplies twist independently to both wheels. Doing so makes it very compact, allowing for larger wheels and a load capacity of over 2000 lbs in a 230 lb aluminum trailer. The ride both loaded and not (the real tell tale) is outstanding. So, definitely a place for them.

Great in theory, but with Chrysler’s dismal quality control in the 50s and early 60s, these torsion bars had a bad habit of snapping. I had a Plyomouth (1957) and a 1965 Dart with them. The Plymouth snapped a bar in front of an Italian rstaurant while I was having dinner and I just saw it SAG! The next one also died when the car was parked.

On the Dart the bars held up well, but the anchors rusted away, a dangerous situation.

Coil springs are cheaper to use…Torsion bars transfer too much load into the body structure of the car, making the car heavier. If the mounting points rusted out, the car was totaled. The lower control arm which carry the full torque of the bar, had to be made heavy and strong…These things pushed the cost up…

A friend of my brother had a beautiful-looking '58 Chrysler two door hardtop, and unfortunately the beauty extended only as far as the thin sheetmetal of the body. Once, while crossing railroad tracks, both of his torsion bars snapped, bringing him to a very rapid stop when the car bottomed out on the high RR crossing.

Apparently, the steel for the torsion bars was not tempered properly, leading to this problem on a whole bunch of '58 Chryslers. Of course, back then manufacturers took responsibility for almost nothing that went wrong after the very brief warranty period.

And, then there was the rust problem, and the overall crappy build quality of the car.

that sounds reasonable

And like the trouble prone Vega aluminum motor, it’s not the idea, it’s the execution.

Did you ever replace the water pump in a Vega…!!!

As Texases said, coil springs are just torsion bars in a coil. But coil springs have some huge advantages. For a given amount of suspension travel, and particular point along the spring has to twist far less than a given point on a torsion bar does. That means that the coil spring, since it’s twisting less, can maintain a much more consistant “rate” along a larger suspension “travel”. Torsion bars “max out” or “tighten up” quickly, coil springs do not.

In applications where space is at a minimum and tightness in the suspension is acceptable, tortion bars are great. In applications where more suspension travel is desired and it needs more consistancy, coil springs are preferable.

A factor in how much the bar has to twist for a given amount of suspension travel is also the length of the lower suspension A-frame (or arm, depending on design), but that gets complicated so I’ll resist the urge to elaborate.