Today I learned about the existence and workings of the weight-distributing hitch. Take a moment to note that both of the Toronados pictured are missing their rear wheels.

This photo lives on the desk of Cecil Eyers (of Eyers Hitch Center, highly recommended), who saw them in person. They were demonstration vehicles for EAZ-LIFT and they drove all around the country as pictured. Under emergency braking the rear quarter panel of one car creased, but after replacing the rear wheels and removing the trailer, the crease smoothed itself out all on its own. This is a strong hitch.

There are two main variables to be aware of in towing: tongue weight and gross weight. Gross weight is what you would expect: the total weight of the trailer with load. Tongue weight is the weight borne vertically by the hitch itself. Most trailers do a pretty good job of keeping the weight mostly centered over their axles (actually slightly forward, for stability when towing. physics!), but with multi-ton trailers it’s harder to strike a balance to within a few hundred pounds at the tongue. The tongue is usually strong enough to support the load, but the added weight on the rear axle of the tow vehicle causes problems on the road.

The weight-distributing hitch solves the problem of an unbalanced (or just plain heavy) trailer exerting too much load on the tow vehicle’s rear axle. Adding rigidity to the vertical axis of the hitch via spring bars links the frames of the tow vehicle and trailer, causing them to act more as one articulated frame.

(want more? here’s more information about towing)