How Hensley Works - simplified

[DesertDog]

Found this while researching hitches.

YouTube - Lego Hensley Arrow Model

[Tim A.]

Hensley has the same video on their website (Hensley Arrow).

[byamcaravanner]

This would have been a better demonstration if the guy didn't exaggerate the magnitude of the sway when demonstrating the conventional hitch set-up and barely rotate the trailer with the Hensley Arrow set-up.

If you look beyond the biased comparison is does give you an idea of the differing functionality.

[BillTex]

The Hensley principle is simple; lighten your wallet by $3000-works great! Much less mass to tow around...

[Tim A.]

Originally Posted by byamcaravanner

This would have been a better demonstration if the guy didn't exaggerate the magnitude of the sway when demonstrating the conventional hitch set-up and barely rotate the trailer with the Hensley Arrow set-up.

You have hit on the point of the little video, but might I suggest that you seemed to have missed that point. The amount of rotation shown with the conventional setup is not possible with the Hensley model, so that is why the trailer "barely" rotates, not because the demo is faked or biased.

[Wayne&Sam]

But he is clearly moving the tow vehicle less in the Hensley portion.

[RIstream'n]

I love it Bill I think that makes alot of sense By the way I'm hearing next week for deivery. I'll let you know

[yakman]

Hello,

I'm still having trouble on where the force of the bow wave from a truck goes? Does it cause the trailer to "crab" behind the truck? The force has to go somewhere. BTW, I do think the Lego video is a bit biased myself. The same amount of force is not applied to the Hensley Lego model. That's clearly evident.

Doug

[dufferin]

some dealers have a big model to show you what you see on the video (CanAm in London - Ontario) and there is no way to have the TV move.

[byamcaravanner]

Originally Posted by dufferin

...and there is no way to have the TV move.

LOL! give it to my 7 year old twin boys... they'll show you how the can "move it" into a number of smaller pieces.

dufferin, If what you say is true, I wish he would have rotated the trailer in the Hensley demo equal to the demo on the standard hitch set-up. Then we could all see the differing affect on the tow vehicle.

Originally Posted by Tim A.

You have hit on the point of the little video, but might I suggest that you seemed to have missed that point. The amount of rotation shown with the conventional setup is not possible with the Hensley model, so that is why the trailer "barely" rotates, not because the demo is faked or biased.

The amount of rotation of the trailer is in direct proportion to the force applied to the trailer. In the demo video, less force was applied to the Hensley trailer. The viewer has no way of knowing the conparative performance based on watching this video.

[dufferin]

Originally Posted by byamcaravanner

dufferin, If what you say is true, I wish he would have rotated the trailer in the Hensley demo equal to the demo on the standard hitch set-up. Then we could all see the differing affect on the tow vehicle.

go check yourself

[HowieE]

Even though I am currently having sway problems with my new TV I would not consider a Hensley.

Yes, the Hensley may have divised a means of absorbing trailer sway before it is transmitted to the TV I have some questions. What does the Hensley do to dampen the sway. Does it just rely on the trailer tires to absorb and thus scuffing the tires unnecessarily.

If the Hensley allows an offset in the hitch as it's means of masking sway transmission it then has a reaction displacement of an equal amount when turning while backing up. On shorter trailer, that are inherently harder to control than longer ones, this could be significant in a tight spot.

[AlbertF]

Originally Posted by HowieE

Yes, the Hensley may have divised a means of absorbing trailer sway before it is transmitted to the TV I have some questions. What does the Hensley do to dampen the sway. Does it just rely on the trailer tires to absorb and thus scuffing the tires unnecessarily.

If the Hensley allows an offset in the hitch as it's means of masking sway transmission it then has a reaction displacement of an equal amount when turning while backing up. On shorter trailer, that are inherently harder to control than longer ones, this could be significant in a tight spot.

I may be oversimplifying the effect of the Hensley, but from my perspective it makes a travel trailer behave like a 5th wheel. The pivot point of a 5th wheel is over the rear axle, eliminating any leverage caused by having the pivot point behind the bumper. A Hensley essentially does the same thing with its trapezoidal linkage that creates a virtual pivot point farther forward - perhaps ahead of the rear axle for a tow vehicle with a very short rear overhang. So I don't think the Hensley can be described as a system for masking sway.

Effective hitch setup involves using all four tires of the tow vehicle to absorb and cancel sway. For that, you need sufficient WDH tension to put weight on the front tires. A low centre of gravity, stiff tires and a suspension system with lots of lateral stability all help.

[2airishuman]

Originally Posted by byamcaravanner

...I wish he would have rotated the trailer in the Hensley demo equal to the demo on the standard hitch set-up. Then we could all see the differing affect on the tow vehicle....

had the trailer been 'rotated' as suggested, with enough force...

the tv/trailer unit would have swung like a rigid pendulum....

as one straight unit (no bending at the hitch) with the tv tires ALL sliding in an arc....

as IF your child was rotating one big rigid stick!

and this would be a supernatural towing event, right?

5ers and ALL other hitches can be jackknifed...

a haha CANNOT be jackknifed, except when backing up....

angulation AT the hitch can ONLY be initiated by the steering tires, NEVER by the trailer.

so turning IS possilbe, as is backing up but unless the hitch BREAKS loose,

"tracking" is always linear, articulated sway is NOT possible, nor is jack knifing...

uniform side PUSH (wind, gravity, slope...) results in the ENTIRE RIG absorbing the force, like center-pushing on a long beam...

so YES the tires/lugs/hubs are stressed (on both vehicles) but the result is NO WIGGLE to correct with steering input.

during forward travel IF

1.some un-natural side force could push on just the BACK half of the trailer...

while...

2. another force from the opposite side pushed on the front half...

the hitch allows for 2-4 inches (approx) of side2side counter movement at the front, that the drive doesn't feel...

sorry folks it is only PARTLY like a 5'er...

IF a fiver had ONE WAY compression/ struts running along EACH side connecting the tv/trailer, ALONG with the pin, it would be a closer match....

but they don't.

cheers
2air'

[byamcaravanner]

Originally Posted by 2airishuman

had the trailer been 'rotated' as suggested, with enough force...this would be a supernatural towing event, right?

2air,

All I'm questioning is; why, in the video, did the guy rotate trailer with the standard set-up more than the one with the haha? He grabbed the haha trailer like he was picking up a marshmallow.

[2airishuman]

Originally Posted by byamcaravanner

... The viewer has no way of knowing the conparative performance based on watching this video.

byamc'

we don't disagree!

and i'll go one further the demo is useless! ok except for chat room fodder..


perhaps the mock up would have broken or collapsed?
how about 'no grip' on the toy wheels?
and so on...

it is like watching video of a guy with a badge whack on a fella without one...

define 'excessive/sufficient/necessary force'...

regardless IF you want or need to understand how a haha works don't waste time on u-tube...

YET...

cheers
2air'

[ScottW]

Originally Posted by AlbertF

I may be oversimplifying the effect of the Hensley, but from my perspective it makes a travel trailer behave like a 5th wheel. The pivot point of a 5th wheel is over the rear axle, eliminating any leverage caused by having the pivot point behind the bumper. A Hensley essentially does the same thing with its trapezoidal linkage that creates a virtual pivot point farther forward - perhaps ahead of the rear axle for a tow vehicle with a very short rear overhang. So I don't think the Hensley can be described as a system for masking sway..

If I wanted a fifth wheel airstream, I'd buy a Pullrite hitch. A little less than a Hensley, and easier to hook up. Still thinking about one, actually.

[HowieE]

Originally Posted by ScottW

If I wanted a fifth wheel airstream, I'd buy a Pullrite hitch. A little less than a Hensley, and easier to hook up. Still thinking about one, actually.

Touche'

An all too often forgotten and better solution. If you TV has the ground clearance to mount a Pullrite they are the answer to most towing questions.

As mentioned I am currently haveing sway problems with my new TV. If I can not overcome them thanks for reminding me of the Pullrite.

[2airishuman]

pullrite pricing...

isn't exactly that much less than a haha...

i rode in a pr setup and nearly purchased one...

till the details were clear.

-each hitch is 'custom' made for the specific tv...

-and generally NOT transferable to any other brand/model of tv...

-they need YOUR tv model info to make the hitch...

-exhaust may need to be moved/rerouted at YOUR cost...

-spare tire may need to be moved; again an owner issue....

-no return policy, except for defects...

-aftermarket tv mods (especially exhaust or suspension) may require a new hitch or return/modify of current hitch..

-some mud flaps are an issue...

-resale is again tv specific (so a unit that fits a 90s f-250 will NOT fit a newer 250)

-base price did NOT include tweaks or shipping...

also i vaguely recall capacity was less than a haha (1200/12000 vs 1400/14000 ?)...

i've forgotten the other things but resale and upgrades and no returns were deal breakers for me...

cheers
2air'

[markjoandall]

Folks,

I might be one of the very few AS's on these forums who have towed with all three hitches listed above.

my first experience was with a chev astro van towing a 27 ft SOB Award trailer. The experience was downright dangerous. I towed the rig from NH to MT without going over 55 because it became unstable and headed for the ditch at 60.

when we returned from MT I purchased a pullrite. The pullrite worked wonderfully and we used the rig for another 7 years. with the pullrite, pivot point is moved forward to just behind the rear axel. just like a fifth wheel.

when we purchased the AS we purchased a new tow vehicle.

I was unwilling to put the pullrite on the suburban because I would loose the spare. I purchased the hensley.

the 30ft classic is probably the most unstable trailers that AS builds. If you research closely in these threads, you will find an underlying theme of the unstable nature of the 30, 31, and 34.

I tow with a marginal vehicle because I need the vehicle for other purposes and an HD diesel Pickup is just not financially practical for me. I converted the 3.73 rear end to a 4.10 and all my tow issues were solved.

We had an experience many of you have had while towing at freeway speads with a severe crosswind. We were on I 40 in New Mexico with a strong wind from the south. The entire rig, tow vehicle and trailer were locked as one straight unit driving down the road. with the wind, the entire 50+ foot unit was canted in the wind. the trailer did not bend at the hitch. The hensley is a rigid link between the trailer and tv. The only the way the rig will bend in the middle is if the tow vehicle initiates a turn. the trailer cannot initiate a bend.

sometimes i ramble, i would much rather ramble down the road with my AS in tow. I would never give up my hensley.

Mark