The conventional ball hitch used to attach travel trailers
to their tow vehicles is inherently prone to sway while a fifth wheel
trailer or a goose neck trailer are not. Why? Because the fifth
wheel and goose neck trailers place the trailer hitch directly over the rear
axle of the tow vehicle. When the trailer's pivot point is over the
tow vehicles axle, the trailer has no leverage to move the tow vehicle
around. The ball hitch used with most travel trailers attaches on or
behind the rear bumper of the tow vehicle. Now the trailer's pivot
point (the ball) is located several feet behind the rear axle. This
gives the trailer the opportunity to move the rear end of the tow vehicle
from side to side when sufficient force is applied.
As an example, let's assume we are going down a
hill. The road turns sharply to the right. If the tow vehicle
slows down without the use of the trailer brakes while turning to the right,
the trailer still wants to go straight. The trailer pushes against
right side of the ball. Since the ball is located several feet behind
the rear axle of the tow vehicle, the force on the ball tries to push the
rear of the tow vehicle to the left. What will happen next depends on
several things: 1) the weight of the trailer vs. the weight of the tow
vehicle, 2) the distance between the hitch ball and the rear axle of the tow
vehicle, 3) the wheelbase of the tow vehicle, 4) the amount of force applied
by the trailer, and 5) the traction the tow vehicle's tires.
Let's take an extreme example to illustrate the
point. Assume the trailer weighs more than the tow vehicle (although
this is not uncommon) and the distance between the rear axle and the hitch
ball has been extended to 7 feet to clear a bike rack (very uncommon to
extend that far), and the wheelbase of the tow vehicle is 7 feet or less
(compact pickup or Jeep). In this extreme case, the trailer would
literally be in control of the tow vehicle. Wherever the trailer
decided to go it would go, it would literally push the tow vehicle out of
the way and jack knife. Hopefully, no one would attempt to drive a
vehicle in this condition. However, the same forces are always at
work, just in lesser degree. The trailers ability to move the tow
vehicle around increases as:
1) the ratio of trailer weight to tow
vehicle weight increases,
2) the wheelbase of the tow vehicle
decreases,
3) the distance between the rear axle of
the tow vehicle and the hitch ball increases.
Short of buying a new trailer or buying a new tow
vehicle, you can't do much about the first two items. Using a
conventional ball hitch, you can make very little change in the third
variable. However, there are two hitches on the market that attempt to
address the third variable, Pull-Rite
and Hensley.
Pull-Rite
The first alternative hitch is the Pull-Rite. This
hitch is attached to a rail that is shaped in a half circle. The
circular rail attaches under the vehicle with the open side of the half
circle close to the rear axle of the tow vehicle. The hitch bar is
attached near the center of the truck close to the axle and extends under
the rail. The special trailer hitch ball unit attached to this hitch
bar. The hitch ball unit uses equalizer bars that are mounted ahead of
the ball thus restricting right-left movement between the trailer tongue and
the hitch bar. In essence, when the travel trailer is hooked up, the
actual pivot point is extended very near the rear axle of the tow
vehicle. This makes a travel trailer behave virtually the same as a
fifth wheel trailer. The turning arc with the standard Pull-Rite is
140 degrees. For a limited number of vehicles, they make a model that
has a 180 degree turning arc. While a 10,000# model with a tongue
weight limit of 1,000# is offered for most vehicle models, a 20,000# model
with a tongue weight limit of 2,000# is offered for a few pickups.
(Pull-Rite makes a terrific hitch for a fifth wheel trailer pulled by a
short bed pickup called the Super-Glide which is the only automatic sliding
fifth wheel hitch available at this time.)
Hensley Arrow
The second alternative hitch is the Hensley Arrow.
This hitch uses the standard tow vehicle's 2" receiver hitch. The
Hensley Arrow hitch head mounts between the standard receiver and the
trailers ball hitch. Using a special arrangement of cams, the Hensley
Arrow hitch head forces the trailer tongue to remain centered in the hitch
head with no horizontal movement. The cams and the design of the
vertical equalizer bar supports (referred to as Jack Assemblies) allow the
Hensley Arrow hitch head to move from side to side and turn to the left of
right based on movement of the tow vehicle but prevent the trailer from
applying force to move the tow vehicle from side to side. This is done
by using the cams to, in effect, extend/project the pivot point to a point
near the rear axle of the tow vehicle. The turning arc of the Hensley
Arrow is 165 degrees. The Hensley is rated to tow up to a 14,000#
trailer with a tongue weight of 1,400# (with the optional weight
distribution bars).
Comparison
The differences in these two hitches are:
The Pull-Rite physically extends to pivot point to the
rear axle of the tow vehicle while the Hensley design "projects"
the pivot point to a similar location.
The Pull-Rite hitch is custom designed for each tow
vehicle. Change the tow vehicle and you will likely have to purchase a
new hitch. The Hensley can be moved from one tow vehicle to
another. The only change that might be necessary is the hitch bar may
need to be replaced (at no cost to the original owner) if the new tow
vehicle's receiver is at a different height.
The Pull-Rite must be professional installed and
frequently requires exhaust system modification. The Hensley requires
nothing other than a standard 2" receiver on the tow vehicle. The
hitch can be installed on the trailer by the customer in 3-4 hours with
standard wrenches and a drill.
The cost of the 10,000# Pull-Rite hitch (exclusive of
installation) is about 75% of the cost of the Hensley Arrow.
The Pull-Rite hitch results in the trailer following the
tow vehicle the same way a fifth wheel trailer does (i.e. you must drive
further into a intersection to avoid having the trailer run up on the curb
than with a travel trailer). The Hensley Arrow equipped trailer tracks
through corners slightly better than it did prior to installation of the
Hensley.
The Pull-Rite hitch allows 140 degrees of turning (180
degree model available for some vehicles allows the same movement as a fifth
wheel). The Hensley Arrow allows 165 degrees of movement,
significantly more than most conventional ball hitches with equalizer bars
attached.
The Pull-Rite hitch retains virtually the same ground
clearance as the conventional ball hitch (the hitch itself under the tow
vehicle appears to extend closer to the ground than a conventional receiver
hitch). The Hensley Arrow sits under the tongue hitch so that the
equalizer bars have about 2 inches less clearance than the conventional ball
hitch with equalizer bars had.
The Pull-Rite hitch has the same number of separate parts
to deal with after unhooking as a conventional hitch (the hitch bar and two
equalizer bars). The Hensley Arrow is designed to stay on the trailer
so the only piece to find a place to put after unhooking is the hitch bar
itself which sticks out too far from the rear of the tow vehicle to be left
on the tow vehicle. If space allows, the hitch bar can be stored in
place in the Hensley hitch box or to a bracket fastened to the side of the
hitch box. The equalizer bars always stay on the trailer.
My Decision
For me, the decision was a no-brainer. I ordered the
Hensley Arrow.
