Norm, As I said *"Now whether the tow vehicle can handle the weight or not is another issue."* If what you say is true then 18 wheelers should be spinning out all over the country as we speak. Obviously, to start with, one needs to know and not exceed the capacities of their hitching equipment. Uhaul doesn't differentiate between sway caused by an over/poorly loaded tow vehicle and a poorly loaded trailer. There is a big difference, even though the end result may be the same (car/boat in ditch). The cause of the problem came from opposite ends of the rig. Yes, too much tongue weight on the tow vehicle can make them unruly. That's why finding just the right tongue weight for some combinations (little car/big boat) can be tricky. If your tow vehicle can handle the weight though, or, if you do something (like a torsion hitch) to equalize the weight on the tow vehicle's axles, more tongue weight will make your trailer more stable every time. Especially if the tongue weight is increased by taking weight (such as an outboard motor) off the transom (ie behind the trailer axle) and placing it up near the tongue (in front of the trailer axle). Something else to consider is; the distance of any heavy object behind the trailers axle(s). this is especially a problem for us with our sailboats and their long overhang behind our trailer's axle(s) One can improve trailer stability by removing something heavy (like an outboard, or a rudder) from the transom of their boat and placing it inside the cabin, or perhaps on a shelf on the trailer frame, under the boat, *just ahead* of the trailer's axle(s). This will take away the pendulum effect of the transom weight (ie long lever arm) and place the weight just ahead of the trailer axle where it will affect the actual tongue weight felt by the tow vehicle very minimally and yet have very little leverage against the trailer axle(s). This from 2,000,000 + miles of personal "research". Rik Norm Bundek wrote:

No, speaking from a stability standpoint, this is just plain wrong. More tongue weight never hurts trailer stability. Now whether the tow vehicle can handle the weight or not is another issue.

The rule of thumb for trailer tongue weight is between 5 and 10 percent of total trailer weight. This does not mean that more tongue weight is a problem, just that you need to have at least 5 to 10 percent to get a fairly stable towing trailer.

Rik

Most trailer weight souces go with 10% - less is okay but seldom more for trailers under 2,000 lbs like ours. Over 10% is a problem according however. Realize these are only recomended! But, excessive weight causes sway according to the Purdue web site below. They did the research - not me.

Regarding tongue weight: Uhaul states no more that 10% as one source: http://www.uhaul.com/hitches/glossary/#tongueweight

The Purdue web site states about excessive weight: http://www.purdue.edu/transportation/vehicle/TowGuidelines.DOC Watch your tongue weight: How a trailer handles down the road depends upon tongue weight. Too much weight will cause the rear of the trailer to sway and make the tow vehicle difficult to control. The tongue weight should not exceed 200 pounds for trailer up to 2,000 pounds. Tongue weight for trailers over 2,000 pounds should be 10 to 15% of the trailer's loaded weight.

The 10% applies to weights over 2,000 lbs. Most M15's will not exceed 2,000 lbs. Extra weight causes sway not more control.

Most sources show 10% as a guideline: http://www.truckstuffusa.com/hitches---winches-hitches.html

Norm M15 #172 _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats