Re: [A/S] Re: Overload Devices On Tow Vehicles

["Carol and Oliver Filippi" <ofilippi@xxxxxxxxxxxxx>]

Jim,

I'm not calling you an idiot, because you do have an interesting observation
which is not the mainstream answer to trailer hitches.  You also allude to
some items which are typically never addressed.

First, one could certainly get away with a non equalizing hitch if the
geometry and weight of the tow vehicle allows.  Namely 1) adequate rear
springs (or other adequate suspension, eg. air bags) - I do not like air
shocks unless part of a factory load leveling system.  2) limited rear
overhang (distance from tow ball to rear axle) to minimize torque on
reducing weight on the front axle. 3) long wheelbase also to minimize torque
reducing weight on front wheels. 4) heavy tow vehicle relative to hitch
weight.

You bring up another  interesting point regarding the negative aspects of
weight equalizing spring bars.  Note that they don't exactly transfer the
tongue weight to the front wheels of the tow vehicle.  What they really do
is put a torque on the frame of the tow vehicle which is perpendicular to
the frame of the tow vehicle.  As long as the trailer and the tow vehicle
are on the same plane (even road) all is well.  The problem comes when the
tow vehicle's frame is not in the same plane  to that of the trailer.  For
example if the tow vehicle went off the road and onto a lower shoulder, but
not the trailer.  Then the equalizing springs would be pushing the front
wheels down and to the left (assuming one is driving on the right).  Under
some conditions, this could cause the tow vehicle to go out of control and
aggravate the situation.

Also, changing the fore and aft angle between the trailer frame plane and
that of the tow vehicle can cause sudden changes in front wheel loading as
when cresting a hill or dip.  In the first case, the "equalizing" load is
reduced, and in the second, increased.  If the geometry of the front end of
the tow vehicle is not stable under substantial changes in load i.e.spring
travel (and goes from understeer to oversteer [or vice versa] like the Ford
Explorer), one could get a bad case of hairy handling (and possibly serious
consequences if the driver has to make an evasive maneuver at the same
time).

Oliver Filippi