"Gary Warner" wrote in message
...

So, any other problems with having a longer trailer tongue?

I have had this argument before, and don't wish to get back into the
mechanics of stability arguments again. BUT......


First word of caution: The 10% tongue weight is a "rule of thumb". Having
10% tongue weight won't necessarialy result in stable rig. Not having 10%
won't necessarialy make it unstable. Having too much will certainly load
down the tow vehicle, which could create problems. Not having enough will
certainly make a receiver type hitch rattle a lot more, and could make the
tongue pop off the ball when you hit bumps in the road.

What makes a trailer stable is the stiffness of the connection between the
axels and the load (springs, center of mass, trailer rigidity, etc.) and the
stiffness of the trailer with load to the tow vehicle (trailer rigidity,
distribution of mass).

For the purpose of discussion, take two trailers, each 20 feet long, axels
in the middle:

Trailer A has all its load located essentially over the axel Tongue weight
could be neutral. Other than the risk of the hitch popping off the ball,
this trailer could tow very nicely.

For trailer B the load is separated into two sections. A little more than
half of the load is centered 5 feet forward of the axels, the remainder of
the load is 5 feet back of the axels. This trailer has the "desired" 10%
tongue weight. Unfortunately, it is likely to sway terribly as you go down
the road.

The difference between these two trailers is the moment arm of the mass. It
isn't a "statics" problem, it is a "dynamics" problem.

To address your exact question: you could have possible problem with a
longer tongue if you don't compensate for the extra "spring". A short
trailer would be "stiff". If you use the same construction and stretch it,
the trailer will become more flexible. This can be very bad. You can avoid
this by making the tongue section more robust. When you figure the load on
the trailer you should consider more than just how gravity effects it. You
need to also consider the side loads during cornering, or when hit by the
wind blast of a passing truck.

You can have a long tongue, there is nothing wrong with that. But it is a
different trailer design than just taking a short trailer and extending it.

Rod McInnis