IN ANY CASE - YOU MAKE THE DECISION, YOU TAKE THE RESPONSIBILITY!

Most opinions have been edited severely and therefore not attributed, (so the nominal originators will get no nuisance mail from here anyway; If you insist on being identified, i will be glad to list your email address, so you can support your point of view. :-)

If you do not agree with the info here, and have constructive comments, let me know; I will add the good ones as i have time.

Please direct all flames and destructive comments to /dev/null.

Definitions

truck

for conversational purposes = the towing vehicle

trailer

for conversational purposes = the towed vehicle

class III, IV hitch

basic "slide in the two inch square tube" hitch type used for towing vehicles; class IV is for greater hitch weights.

weight distributing (WD)

adjust the relative weight on the truck's front and rear axles so steering and braking control is optimized (pitch control in airplane lingo). This is done by clamping steel bars to the trailer tongue and tightening chains to "lever" the front of the truck down, to compensate for the hitch weight of the trailer pushing the back of the truck downwards and lifting the front tires off the road.

anti-sway (AS)

damping the trailer induced sideways forces on the truck bumper located pivot point, which are caused by the trailer being hit with wind gusts or whatever. These forces tend to force the truck to turn (yaw control in airplane lingo). Controlling these forces can be achieved with several different techniques:

with adjustable friction devices between the truck and the side of the tongue to dampen the forces.

better hitch design

mechanical additions to change the way these forces operate

Pullrite and Hensley reduce or eliminate sway by moving the pivot point. (see lever arm discussion)

Note - Most friction type sway control manufacturers recommend disconnecting them under adverse weather conditions - just when you would seem to need them most.

Geometry

the layout of the hitch and vehicles that determine how towing and perturbation forces (sway) are applied to the truck-trailer combination. Also see the Hitch Geometry discussion below.

hitch point

where the trailer is connected ( hooked up) to the truck.

pivot point

the connection point between the truckand the trailer tongue ; ie - where the trailer tongue angles sideways from the truck;
The trailer ball marks this point for simpler hitch systems
but it is near the axle for fifth wheel and Pullrite.
For Hensley, it is designed to move around.

see the Hitch Geometry discussion below.

lever arm ( for the truck)

the distance between truck back axle and the pivot point.

a basic physics term. think of a teeter-totter, or a crowbar, or Archimedes and moving the world.

tongue, or towbar

the mechanical connection between trailer and truck. Its length is the distance between the trailer front axle and the pivot point. For simple hitch, this is all on the trailer ( ball to trailer axle), but with Pullrite the Pullrite towbar is locked onto the trailer tongue.

sensitivity

especially when backing up, how radically does the trailer respond to the truck turning;

high sensitivity means a small turn of the steering wheel can make a lot of difference in the trailer turning. ie - it is easier to screw up when backing with a high sensitivity system :-)

low sensitivity means you need to turn the steering wheel more to make things happen. ( ed - I proclaim this as "good" :-)

max turn angle

the greatest angle between truck and trailer you can get during turning,
ie - the angle when the truck rear corner just kisses the trailer front corner. See this - ed..

fanaticism

a character trait of some people who vehemently maintain their opinion; often excludes tolerance and facts.

Discussion

Ignoring the truck's need for a super strong bumper, great brakes, plenty of power, etc. we are talking about 2 needed hitch functions: weight distribution and anti-sway . We here ignore the important anti-sway factor of correct hitch height.

the Hensley and Pullrite are purportedly better (and certainly higher $$$) version hitchs than the basic "ball at the bumper" system. They have special designs to provide some of the above functions.

Many argue whether the added gizmos are worth the price difference. Opinions seem to depend a lot on relative size/weight of truck to trailer, driving experience and skill, and maybe luck.

What does not seem to get mentioned much, is that the Pullrite and fifth wheel type hitches eliminate the need for antisway gizmos by eliminating/reducing the sway problem in the first place (by reducing the truck 'back axle to hitchpoint' lever arm). Hensley hitches try to do the same thing with a special complex design.

Fifth wheel hitches are excellent and common, but not usable for airstreams; so little discussion of them here. Pullrite is similar to them, is usable and available for airstream type trailers.

There are a plethora of opinions about these different towing systems (often fanatical :-) , but I have not been able to find any scientific test results.

Different Hitch Type Pros & Cons

Hitch Geometry Details

sorry - no pictures here - too much trouble. :-)

type	basic class III	Reese or other brand weight distributing hitch, with anti-sway bar	fifth wheel and gooseneck (not used with Airstream towing setup)	Pull-rite	Hensley
effective towing pivot point	towball at rear bumper	towball at rear bumper	truck kingpin connection above rear axle	truck kingpin connection near rear axle	forward of hitch ball
effective backing pivot point	towball at rear bumper	towball at rear bumper	kingpin connection above truck rear axle	kingpin connection near truck rear axle	towball at rear bumper
truck-trailer separation distance	short	short	truck & trailer never touch on turns	truck & trailer never touch on turns	longer - hensley mechanism add 18 inches of separation
Length of tongue	short - towball to trailer axle	short - towball to trailer axle	long - truck rear axle to trailer axle	long - truck rear axle to trailer axle	short for backup/long for towing (but see above)
turn angle limit see this	45 degrees	45 degrees	90 degrees	90 degrees	45+ degrees

The different geometries determine where forces can be effectively applied.

All systems have forces at the tires, where the friction against the road prevents them from moving sideways.

All systems have forces between the truck and trailer at the pivot point.

Basic design conjecture: Moving the pivot point to the truck back axle minimizes the effect of sideways sway or vertical weight forces on the truck, since they no longer can twist the truck about the rear axle; the lever arm to apply the forces and turn the truck is gone. Vertical forces are applied to the rear axle springs directly, and sideways forces are counteracted by the rear tires traction, (the sideways friction forces).

The Pullrite design provides a very stiff connection at the hitchpoint (towball) which effectively adds the Pullrite towbar length to the trailer towbar length to make a very long single towbar(tongue) attached and pivoting at the pivot point where the Pullrite connects to the truck - near the truck back axle.

This very long towbar swings under the truck during turns, (with a special stop to keep this towbar from hitting the truck rear tires) so you can imagine how very sharp turns up to 90 degrees are possible.

The Hensley mechanism uses special mechanical trapezoidal linkages to effectively move the pivot point for towing toward the front of the truck. See simplified diagram. The patent helps, but is typically vague and abstruse at the same time.) Theoretically, i suppose the effective pivot point could be anywhere in front of the truck hitch ball, even in front of the truck!!! The optimum spot would be somewhere in front of the truck center of mass so any sideways forces would tend to straighten out the truck, rather than turn it for the worse like a normal hitch would.
But this virtual mechanism is not active during backing, so it backs up like a bumper mounted towball system. (complete explanations invited on this point from those who know.)

The Hensley mechanism inserted between the hitchball and the trailer ball-socket also extends the trailer tongue length so the trailer front will more easily clear the truck corner on sharp turns.

and another author explains:
The difference with a Hensley is that the pivot point is mechanically transferred to a point near the rear axle through linkages, very similar to the principal of a 3 point hitch on a tractor. I believe the inventor got the idea for the Arrow from his knowledge of farm implements, but I'm not 100% sure. When towing straight down a highway, the point of convergence (virtual pivot) is actually out in front of the tow vehicle. As soon as a slight turn is incurred, this point moves back to near the rear axle by the simple action of the mechanical linkages. Only when you make a VERY hard turn (as in backing into a campsite) can you get these linkages to "breakover" and allow the full 165 degrees of swing. At this point the pivot is at the hitch, although I can't imagine anyone being able to get to the "breakover" point doing more than 2 MPH! Actually the principal of the hitch is very simple, just difficult to explain. There used to be a URL that explained how this linkage system worked pictorially and it really clears things up. See this - ed.. I use a Hensley and the stability and handling is truly incredible, and I have also used traditional friction/cam-type sway control. There is no comparison.

Special Setup Requirements For Hitch

>One of the best descriptions of proper hitching is on
>http://www.can-am-rv.com. It tells you all about how to set the ball
>height, adjust the equalizer bars, etc.

Opinions and Facts

> Well I reckon I am going to have to take a look at one of these Hensley
> hitches.  I can't imagine what sort of contraption would be worth that kind
> of price.  'Course the world is full of things I can't imagine so I will
> hush 'till I no more about those gizmo's.  Maybe I should start
> selling/installing them at my shop?

TO Me the Pullrite advantages are: It is 1/2 the cost of Hensley

Also, the hitch has good resale value. Put a good used one on the Internet for $1200 to $1500 and it will be gone in about two days.

The Hensley Arrow is well named. Your towing vehicle and trailer go down the road straight as an arrow. It pulls like a dream. It locks your trailer to the tow vehicle and it feels like your pulling a single large vehicle.

Its minuses are: (1) Cost - twice a much as Pullrite, aggravation of hookup and unhooking.

The Hensley is designed and manufactured to be the best. I like the way I am treated as a customer.

You will have to figure out which works best for you. Both Pullrite & Hensley are good companies which treat their customers well. Order video from both of them. You will then begin to see which might be the best choice for you.

On my personal unit I have a Pull-Rite. On the work unit we use a Hensley. There isn't a night and day difference, but I prefer the Hensley for a couple reasons.

First, I feel that the Hensley is more stable. I have never had either unit in a position where I felt a jacknife was imminent, but the Hensley just "feels" more stable in cross winds and when trucks pass.

I have met the owner of Hensley Manufacturing, and he claims to have objective data to prove the Hensley is really better. He also told me that if he were me he wouldn't trade the Pull-Rite just to get a Hensley. He thinks his is better, but not better enough that it justifies removing the Pull-Rite. He also told me that he feels the Pull-Rite and the Hensley are the only two safe hitches on the market. I agree with him.

Hooking up Differences

the trailer can be at any angle to the truck - a great convenience.

For Hensley, I should say -- aggravation of hookup and unhooking. Hooking up requires backing the draw bar in to the hitch receiver at precisely the same angle and level that you unhooked. Lots of Hensley owners have developed tricks and techniques for dealing with this, but some never get over the frustration. I'm closer to the latter group.

Backing Up Differences

I talked to fifth wheel folks, and Pullrite vendor here in Houston, who describe the backing process as different, not harder-

This last comment makes sense to me, since the Pullrite connection geometries are different, like the fifth wheel geometry.

there are geometry factors that make a difference when backing up:

Pullrite backing is less sensitive than a regular hitch to steering wheel turning (until the truck gets to large angle to trailer, when they are about the same)

The longer (truck-end) lever arm of a regular (and Hensley) hitch multiplies any truck backing turning motion on the trailer ==> backing action is more sensitive.

For example

While for 5th and Pullrite , the geometry is just like a semi truck: the effective truck trailer connection is near the back axle , usually < 10 inches from it (a short lever arm) -->the same 10 inch sideways motion in truck front may move tow connection about 1 inch sideways.

This means more steering wheel motion is needed to make more "front of truck" motion to make the same amount of turn whilebacking. Therefore, backing with the Pullrite is less sensitive to steering wheel turn amount.

...having backed a bunch of 4 wheel hay wagons in my youth, i can attest to the advantages low sensitivity here. :-)

N.B. - When you get to the max backup turning angle between truck and trailer, with the Pullrite you can almost pivot the trailer on its tires. eg- "turn it on a dime".

BTW - this short truck lever arm is also the reason that the dreaded sideways sway forces have little effect on the 5th, Pullrite, Hensley, & semi truck compared to the regular hitch truck: - there is a much smaller lever arm , which reduces sideways forces back through the tow connection to the truck. ( about 1/5 for above example)

And no extra antisway friction gadgets are needed to do this.

Turning Radius

It is basically determined by

in general, the

if you have a long tongue trailer, you can turn until the tow shaft is almost parallel to the back bumper; because nothing on the trailer hits the truck before the side of the tongue hits the bumper; -->you can approach a 90 degree truck to trailer turning angle.

But, with short tow shafts like with most travel trailers, as the turn gets tighter, the rear corner of the truck will kiss the front corner of trailer, severely limiting the turns - -->you can, at best, get up to 45 degrees between them while turning (my estimate)

the 5th wheel & Pullrite geometries always keep all of the trailer behind and away from the truck, regardless of the turn angle,
ie - they have a long tongue trailer geometry
so it insures all of trailer stays "out of touch" with the truck.

The Pullrite hitch is design limited for a max turn of abput 70 degrees or so, which is, I estimate, about 30 degrees more than the max turn angle for an Airstream with another type hitch. (But you can also buy a 90 degree turn Pullrite hitch if you want.)

BTW - The 5th wheel & Pullrite allows the truck & trailer to be parked at a large angle, so you have unhindered direct access into the back of the truck bed.

(ed - can anyone confirm if anything more than the length of the Hensley mechanism is a factor for it to make tighter turns than regular hitch? What degree angle of turn is max?)

Comments

 
the pivot point is near where it would be on a conventional hitch
or the Hensley. This allows MUCH tighter turns, and makes the unit
much more maneuverable. 

The Pull-Rite, though, is still more
maneuverable than a conventional hitch. I used to tow a 37' trailer,
and made a U-turn on a two lane road. I used both shoulders, but I did
it without a problem.  Try THAT with any hitch other than a Pull-Rite
or Hensley!!

Installation, and Moving Gear to another Vehicle

Comments

 Is it a do-it-yourself job, or do I need to be
 prepared to get out the arc welder, or see a professional? 


The Hensley is installed on the trailer and stays on the trailer. 
(There is nothing on the truck to install, assuming you have the class III hitch.)

>My soon to be ex installed my Hensley.  He was one of those men that
>had to think about every step..... worked slowly, methodically.  He
>called Hensley's 800# twice for technical help.... it took him approx
>4 hours to install it.
>
>After it was installed he said if he had to do it again it would take
>20 minutes.

When you change trailers with a Hensley:
if your new one has a different towing height, you will need to
buy a new draw bar. ($125).

The Hensley folks will give you a new bar for free with the return of the
old one.

If the A frame or coupler is different, you will need to buy a new
set of brackets for the struts and load leveler jacks $(150).

Another point in the Hensley's favor is that it stays with the
trailer. It attaches to any tow vehicle with a standard 2"
receiver. Pull-Rite makes a different unit for each tow
vehicle. Unless you replace your tow vehicle with an identical unit,
you need to buy a new receiver. Last time I did that, in 1993, it cost
me about $700 for a receiver. If I had a Hensley I could have
exchanged that attachment bar if I needed a different offset. I think
they exchange for free.


Now that my Hensley is almost paid off, I feel even better about it.  I
bought it on the 12 month no interest plan, so I have one more payment!
Then its mine!


The last hitch I used
before and after the Hensley was the Reese with the dual cam sway contol
along with a friction sway device as well.  The Hensley is more stable and
makes me feel just safer at all times.

For Pullrite, on most vehicles modifications are required to install it. We
used that combination until buying and restoring a 20' Argosy MH and
then a 24' A/S Motor Home. We are now back to pulling a trailer with
Dodge Ram 2500 24V Diesel. Choosing Pullrite would have required
losing my spare tire carrier under the bed and a modification the the
exhaust system. For that reason, I chose Hensley this time.
 see this


For Pullrite,
The gear that goes on the trailer can be moved in 5 minutes.
Its just a couple of steel brackets, each held on with a bolt.

Loosen the bolts a few turns, move to other trailer, and tighten.

What Pullrite stuff goes on the truck?
(After the Pullrite equipment is mounted on the truck)
it is a heavy trailer ball mount that slides into the
class III type 2 inch square tube .


Pullrite cost?
i asked a local dealer (about 1997) ....
he would sell a new pullrite for $900 and install it for $1300
including
	 spare carrier removed, and
	tailpipe reworked to exit the side.
i figure that still leaves > $1200 between pullrite and hensley initial costs,
presuming Hensley installed cost is $2500.


I tend to keep vehicles a long time, so vehicle change is less of a
factor for me.
But, for say, $500 to pay for someone else doing the
removal and re-installation, i figured i could move the
pullrite to another similar vehicle twice before it cost as much as a
hensley.


>  There's nothin' to that R&R of a Pull-Rite. Get out your torch, cut
> it off.  Slide it under the new machine (balance it on your floor
> jack), fire up the welder and have at it. An hour or so later,
> you're ready to roll.  What's so tough about that? :-)

You can buy a used pullrite for $300 or so (mine was $250), and get a welder to redo it to fit your truck (if needed) and have a super rig for very few $$$.