When to unhook

Johno02 wrote:
The problem with backing up a car behind anything is the tendency of the front wheels to caster, or turn to the limit on one side or the other. If the front steering is locked straight, an experienced person should be able to back one. What actually happens is that the wheels turn hard to one side, and you can severly damage either the steering or the tow bar and brackets, or both. Most people have backed one up for a short distance, especially if taking it very slow, and generally in a straight line.
So the correct answer is anytime you want to back up! If we are going to a campground, one of us will go in and register or whatever, and the other will disconnect the toad. Its not a big thing, usually less than a minute with our Blue Ox towbar and brackets. Generally the rule is if the toad is hooked up, you don't have reverse.

In the old days, front suspension reaction to backing up could be simply determined by the positive or negative caster angle. Some cars now have front suspensions like the McPherson strut. In these cars, the steering axis inclination and the offset between center of the tire and the intersection of the steering axis and the ground coupled with the camber can be designed so that the front tires attempt to remain straight whether you are going forward or backward (when the front wheel turns to either direction the turning action tends to lift the front end, and the weight of the front end pushing down {gravity at work} tends to straighten the wheels). Also, with some of these newer front suspensions, the caster is set negative (some BMWs come to mind).

So, with some cars, the front wheels tend to try and stay straight when backing up instead of trying to swing to max left or right when backing up.

Depending on your cars front suspension characteristics, you may find it relatively easy to back up, including backing through turns. On other cars, you may experience the sharp turn to one side described above.

I suspect that this is why some people can back up with the toad attached with little difficulty (including making turns), and other people experience severe problems. It's not the skill of the driver as much as it is the design of the Toad front suspension! AKA one size doesn't fit all.

YMMV :B