RobG wrote:
The little ATV trailer with a quad on it is pretty light... but consider the lever effect of a hitch extension multiplies your otherwise low tongue weight (which I estimate at maybe 300 lbs) to more like 1200. So you're right -- unhook the trailer and you're closer to your proper weight. BUT, that means not towing. I would not want to risk going that far over on my tire ratings; that's one place you don't want to mess around. The last thing you want or need is a blow-out because of it, especially at freeway speeds.
But, it's your stuff... if you want to risk it, that's up to you. BTW if you do have a blowout and it causes an accident, the cops WILL look at that sort of thing.
The moment arm "level effect" as you call it does not increase the weight of the tongue from 300lbs to 1200lbs. The moment arm is the amount of twisting force exerted by the tongue of the trailer to the hitch and transferred to the frame of the truck. This is different than the static load (or dynamic when moving) that the tongue weight will add to the tires themselves. The 300lb tongue weight (likely closer to 150lb if he could lift it by hand) is just 300lbs as far as the rear tires are concerned.