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posted to alt.rv,alt.rv.pop-up-trailers,rec.boats,alt.rv.pop-up-trailers
Norman D. Crow
 
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Default Drawbar Length - How Long?



"tobe" wrote in message
. ..
Lengthening the trailer tongue is a different matter from lengthening the
distance from the ball on the ball mount to the tow vehicle.

In the former, the center of gravity of the boat/trailer is farther from
the center of gravity of the tow vehicle, but that by itself doesn't make
much difference in towing and handling (all else being equal).

However, if the distance from the tow vehicle to the ball mount is longer,
any sway in the trailer has much more of an effect on the handling of the
tow vehicle. Think of a lever and fulcrum. The longer the lever from the
fulcrum, the more movements are magnified.

Common lengths, from the hitch pin hole to the ball hole, are around 8
inches, with the longest I have commonly seen about 11 inches (and the
shortest something like 6 inches). Not all hitches have the same distance
from the back end of the hitch to the end of the vewhicle (bumper...),
and, of course, not all vehicles have the same distance from the center of
gravity or the rear axle to the hitch. Therefore, I would imagine that
the length of the ball mount in the ranges commonly available will not
have much effect on towing. The most important factor is probably tight
turns, with the trailer not running into the tow vehicle (pretty hard to
do with a standard pop-up configuration!).

Note that there are hitch ball mount 'extenders' available in lengths up
to 18". These usually state in the fine print that the maximum towed
weight should be reduced by 1/3 if using these, and I would also imagine
that any sway in the trailer could be dangerously amplified.


Agreed. Ideally, you want the actual ball mounting position as close to the
rear axle of the tow vehicle as practically possible. If you ever take note
of the guys who transport mobile homes for a living, they are generally
driving a single axle road tractor that has been modified to put the ball
mount as close to the rear axle as possible. Someone in this thread
mentioned an "obscenely expensive" hitch that makes believe the hitch point
is @ or near the rear axle, good thinking.

This is why, with an OTR history, I chose to go 5th wheel. I've seen too
many trailers towed by ball hitch where the tail started wagging the dog.

I wasn't aware they made ball mount extenders, but the very thought scares
me. Same thought as going down the road with my 16K slider in the
maneuvering position.

Ladies & gentlemen, I haven't lurked here long, so if my statements are
objectionable, feel free to fire away. Cut my teeth in Usenet & always wear
the flame retardant undies. I'm making statements about things I think I can
contribute to, but there's a whole lot about RVing I DON'T know, and may
likely ask some stupid(to some) questions(then again, the only stupid
question is . . . ).

--
Nahmie
The only road to success is always under construction.