You know those big camper vans you get (Americans call them RUV's) that sometimes tow a car behind them?
How does the car steer when being towed with all 4 wheels on the road and no-one in it? 
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Posted 8 months ago #
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The same way a four wheel trailer does, just follows the camper
Posted 8 months ago # -
Not quite the same. Normal trailers pivot around centrally mounted axles. Cars being 'flat towed' do not. They behave like normal cars.
They are attached to the towing vehicle by an A frame, rather than just a normal tow hitch.
Each 'bottom' of the 'A' attaches to the towed vehicle at either side, and the 'point' of the 'A' attaches to the towbar of the towing vehicle as would a normal trailer. With the towed car attached at two points, its direction is therefore dictated by the towing vehicle - basically the car has to go where it's pulled because it can't go anywhere else.
The geometry that makes any car's steering self centre (castor angle) is what allows the car to track faithfully. The wheels will point wherever they need and nowhere else.
Doesn't work in reverse, as castor is only there going forward - note how your steering doesn't self centre when you're reversing (unless you have a Citroen SM).
And you have to make sure the keys are in the ignition so the steering lock is off, or horrible things will happen. Interesting horror stories about what can happen when it goes wrong...
Posted 8 months ago # -
Geometry innit!
Besides which the majority of those cars being towed along are over 700Kgs and probably don't have any braking system set up so are illegal too
Basically you leave the steering lock off and let the towing vehicle drag the other car around.
and they are normally called RV's Recreational Vehicle
Posted 8 months ago # -
Midgets innit? (can I say midgets?)
Posted 8 months ago # -
They have a crude braking system that consists of an over-run type hitch that would be fitted to a braked trailer, this uses a cable that is attached to the brake pedal in the towed car. However, this will mean the cars brakes will be applied when you try to reverse, but this is largely irrelevant as after a few metres the car will wind onto full lock and you will be stuck
Some users of A frames seem to have convinced themselves there is a grey area within the law which means they don't need auto reverse brakes, the rest just know the police turn a blind eye. Even if the car is a beach buggy under 750kgs, it will still have brakes fitted which means they must be in working condition when towed.
I don't really see the attraction, I would much rather have a small trailer that can be reversed to your hearts content, saves wear and tear to the car, and doesn't (if you use a car cover) leave your car covered in road grime and stone chips
Posted 8 months ago # -
It's a bit of a grey area isn't it? I know a couple of chaps who tow like this regularly - they have the overrun mechanism on the A frame's tow hitch operating on the brake pedal of the towed vehicle so it's braked.
Therefore they tow with the assumption that legally the car is classed as a braked trailer.
Edit:
Some users of A frames seem to have convinced themselves there is a grey area within the law which means they don't need auto reverse brakes, the rest just know the police turn a blind eye.
Ah. Bit naughty then, if harmless.
Posted 8 months ago #
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