The word “Torsion” has become such a buzzword in the trailer and hitch community that its become impossible for most people to decipher its true meaning. Some products have round bars, some have sway bars, and some have these mysterious “torsion bars”. What’s the difference? What exactly is a torsion bar?
Torsion is the action of twisting one end of an object relative to another. When referring to vehicles, the torsion bar is the object connecting the vehicle chassis (its skeleton) with the suspension system. The torsion bar is rigidly attached to the chassis, but more loosely attached to the suspension. This allows the torsion bar to move in a way similar to modern day independent coil spring suspension systems.
Whether its a torsion bar or independent coil springs, having a proper suspension system is vital, because the alternative would be to mount the wheels and other parts of the car directly to the chassis.
Of course the real question is, how does torsion relate to trailer hitches? The answer is, only marginally.
Torsion Bars are often conflated and misconstrued to be similar or related to weight distribution hitches, but this is a misconception largely based out of a fundamental misunderstanding of how weight distribution hitches operate.
Weight Distribution Hitches (WDH’s) operate using spring bars to create leverage and balance the amount of weight being put on the front and rear axle of the towing vehicle. As you can imagine, this is a different principle than torsion bars.
This is not to say that the two topics are entirely unrelated however. Both rely on advanced physics and engineering to stabilize the chassis of the towing vehicle and avoid excessive strain on the whole. However, Torsion bars are primarily used for suspension systems, and have declined in relation to motor vehicles due to the prevalence of independent coil spring suspension systems.
Are torsion bars a dated technology? When it comes to motor vehicles, yes. This is largely because torsion bars are bulky and intrusive, whereas a hitch is a rear add-on to a vehicle. As of 2022, torsion bars are most often used for military style vehicles like tanks, which require a greater amount of shock absorption than standard coil springs can provide.
So next time you see someone mention “torsion bar hitches” as some kind of marketing buzzword, don’t give it a second thought. Torsion bars are a vehicle suspension item, not a towing and a hitch concept. For more esoteric hitch and vehicle questions, stick around and bookmark the Fastway Trailer blog today.