The Andersen WD Hitch User Thread

[Ron Gratz]

Originally Posted by SteveH

Please provide us scale data that shows significantly different load on an any tow vehicle axle with the exact same height measurements.

Steve, sorry to keep you waiting.

Data such as you have requested can be found here: RV.Net Open Roads Forum: Towing: Which Choice?

For your convenience, I've plotted the 22 sets of height-load values on the following chart.

If your assertion were correct -- "If the height is the same, the weight is the same." -- there would be only one value of load for a given value of height.

In fact, these data show the assertion is not correct.
For example, for a height value of 19-3/8" (19.375), there were four values of load -- ranging from 4500# to 4760#.
I leave it to you to decide if those are significantly different loads.

[SteveH]

Ron, I'm sorry, I see absolutely no cat scale weight tickets, so how do we know any of this is real?

And you've not answered any of my questions of you from my last post.

Do you own and use an Andersen hitch? Do you own and use ANY weight distribution hitch? Do you own and tow an Airstream?

[ROBERTSUNRUS]

Originally Posted by Ron Gratz

Steve, sorry to keep you waiting.

Data such as you have requested can be found here: RV.Net Open Roads Forum: Towing: Which Choice?

For your convenience, I've plotted the 22 sets of height-load values on the following chart.

If your assertion were correct -- "If the height is the same, the weight is the same." -- there would be only one value of load for a given value of height.

In fact, these data show the assertion is not correct.
For example, for a height value of 19-3/8" (19.375), there were four values of load -- ranging from 4500# to 4760#.
I leave it to you to decide if those are significantly different loads.

Hi, I also agree that if the ride height is the same, the weight on the axles will also be the same. What I haven't read here is the fact that both of the tow vehicle's front and rear fenders must be at the same [original, unloaded] ride height for this to be true. So if the front fender is the same ride height and the rear is lower, the front would be a bit lighter.

[HowieE]

Come on Ron what does this data relate to that has axle measurements of 19 to 20 ins. and front axle weights close to 5.000 lbs.

My point of measurement on my Excursion is closer to 38 ins. and even my diesel is not close to these front axle weights.

Please name what you are working with and where these data point come from.

[Airtandem]

Don't confuse me with the facts; my minds made up. Just a quote, I've tried Reese, Equlizer and Andersen. I wanted to try the Pro Pride, but $$$ kept me from it. I will also add that the weight of the various hitches was a BIG consideration.

[Aage]

Time to cool off, and remember thar simplest of rules that we have here on Airforums: Be Nice.

Insulting each other and carrying on in a generally rude manner will not be tolerated, and you all know that. And I also believe that you know the consequences if you can't treat each other civilly.

Also, lastly: I will remind you that there is nothing requiring members to actually own any particular equipment that is being discussed here to participate in the discussions.

<<Mod hat off>>

[Friday]

Originally Posted by Airtandem

Don't confuse me with the facts; my minds made up. Just a quote, I've tried Reese, Equlizer and Andersen. I wanted to try the Pro Pride, but $$$ kept me from it. I will also add that the weight of the various hitches was a BIG consideration.

And that is where a lighter-weight setup like the Andersen fits in for me... I have 650lb tongue weight... 4500lb trailer... I don't need to shift a lot of weight, just a bit. But, I hang a mega-hitch on there and now I've got 850lbs, plus the ball is 2 feet further back increasing the leverage of the trailer... now I NEED to move 600lbs to get back into trim.

Andersen... tucks in close, weighs 50lbs... a few cranks on the chains to pop it up and away we go.

For monster rigs with monster tongue weights... maybe not within capacity...

That doesn't mean it won't work for many people.

[HowieE]

As I see more and more Streamers adopting the Andersen I am waiting to see the first one go back to their previous system.

That, unlike feeble attempts to discount the hitch, will be the type of TEST that will have some weight on public opinion.

Repeated comments from none users and those with other vested interest make for exciting attempts at point counter point but have done little to dissuade those who are satisfied users or slow the adoption of the Andersen.

[Ron Gratz]

Originally Posted by HowieE

Come on Ron what does this data relate to that has axle measurements of 19 to 20 ins. and front axle weights close to 5.000 lbs.

The poster's tow vehicle and trailer are described at the bottom of the post to which I provided the link.

If you read, you will see the data are for a 2010 F-350,6.4PSD.

The poster wanted to have height data which were not influenced by tire compression so, instead of measuring from the ground, he measured from a mark on the wheel hub.

Ron

[Denis4x4]

Originally Posted by Aage

Also, lastly: I will remind you that there is nothing requiring members to actually own any particular equipment that is being discussed here to participate in the discussions.

<<Mod hat off>>

That said, the credibillity or lack thereof, on these discussions is certainly suspect!

I've put together advertising and marketing programs for automotive aftermarket performance products that were sold more sucessfully on the emotional level than the practical one. I plan on buying an Anderson based on the input of the USERS posting here. I'm also unsubscribing to this thread as everything that needs to be said has been said at least three or four times?

One last thought: wonder how many times posts coulda, woulda, shoulda, been edited if it weren't for the 30 minute rule?

[Ron Gratz]

Originally Posted by ROBERTSUNRUS

Hi, I also agree that if the ride height is the same, the weight on the axles will also be the same.---

Bob, you could try a simple experiment --

If your tow vehicle has some point at the front center under which to place a jack, you can do the following:

First, on both front sides, mark a reference point on the pavement and a reference point on the fender above the axle.
Bounce the front of the vehicle up and down a couple times to try to get the front at a "neutral", unloaded height.
Measure the fender heights on both sides.

Then, use the jack to lift the front of the TV until the fender heights have increased by about 1".
This will simulate the initial lifting of the front due to tongue weight without WD.

Then lower the jack until it no longer is carrying any load.
The load on the front axle now is the same as when the first height measurements were made.
Again measure the fender heights on both sides and see how the heights compare with the first measurements.

I performed this experiment on my Ford Explorer this afternoon.

I first placed a short piece of 2x4 on the pavement directly below each axle's centerline.
I placed a piece of masking tape on each fender directly above the axle's centerline.
I placed a mark on each piece of tape at a height of 33" above the 2x4.

I then jacked the front of the Explorer until each side was 1" higher than before.
When the jack was lowered and removed,
the passenger side tape mark was at 33-3/16" and
the driver side tape mark was at 33-1/4".

With exactly the same load on the front axle, the front wheel wells now were 3/16" and 1/4" higher.

What I haven't read here is the fact that both of the tow vehicle's front and rear fenders must be at the same [original, unloaded] ride height for this to be true. So if the front fender is the same ride height and the rear is lower, the front would be a bit lighter.

I agree, but we need to quantify "a bit".

If the rear is lowered relative to the front, the TV's center of gravity will shift slightly rearward (assuming the CG is located higher than the axles).
This will cause a slight decrease of load on the front axle and increase on the rear axle.
The question is, how much.

If the TV weighs 5000# and is "level", the front axle load might be 2750# (55%) and the rear might be 2250#.
If the CG is 13" above the axles and the wheelbase is 130" and the rear drops 1" relative to the front, the CG would shift approximately 0.1" rearward.
The load on the front axle would decrease by about 4# and the load on the rear would increase by about 4#.

Ron

[ROBERTSUNRUS]

Originally Posted by Ron Gratz

When the jack was lowered and removed,
the passenger side tape mark was at 33-3/16" and
the driver side tape mark was at 33-1/4".

With exactly the same load on the front axle, the front wheel wells now were 3/16" and 1/4" higher.




Ron

Hi, this is partially because of the Camber on the wheel alignment. That's why alignment racks have ball bearing wheel pads. Jack up the rear of a VW bug [ old models] with the rear axles swinging inward on the bottom; Let it down and it will be several inches higher until you roll the car a few feet.

[HowieE]

Originally Posted by Ron Gratz

I first placed a short piece of 2x4 on the pavement directly below each axle's centerline.
I placed a piece of masking tape on each fender directly above the axle's centerline.
I placed a mark on each piece of tape at a height of 33" above the 2x4.

I then jacked the front of the Explorer until each side was 1" higher than before.
When the jack was lowered and removed,
the passenger side tape mark was at 33-3/16" and
the driver side tape mark was at 33-1/4".

With exactly the same load on the front axle, the front wheel wells now were 3/16" and 1/4" higher.

A simple but effective deminstration of mechanical hysteresis and no one can deny it's presence.

However this measurement is not the one we have been discussing while setting up the hitch. We are talking about measuring the fender height TV empty and the fender height AFTER adjustment of the hitch. The point in time you are noting will be passed through during this adjustment have have no bearing on anything.

In fact if one assumes that the condition you note is present every time and the hitch returns the fender height to or past its original height it has had to exert even greater force to do so. That component is called weight transfer. You know that which all the nay sayers are claiming does not exist.

Now keep the home fires burning guys as I am taking my rig with my Andersen and going south for a while. Will be reading the tread but may not be in a position to post. I expect to convince several Ha Ha users to convert while on the road by showing that time hitching and effort are not required to have a good ride and sway control.

Considering the cost of fuel the Government ought to get behind Andersen and offer subsidies for the reduced fuel cost and environmental consideration by not have to burn a ton of coal to make those monsters and haul them down the road.

Have Fun

[Ron Gratz]

Originally Posted by HowieE

A simple but effective deminstration of mechanical hysteresis and no one can deny it's presence.

However this measurement is not the one we have been discussing while setting up the hitch. We are talking about measuring the fender height TV empty and the fender height AFTER adjustment of the hitch. The point in time you are noting will be passed through during this adjustment have have no bearing on anything.

Howie, you're missing part of the picture -- and, probably, the more important part.
Suspension hysteresis (a.k.a. "stiction effect") works
both when the front is raised above the unloaded height followed by a reduction of lifting force
and when the front is forced below the unloaded height followed by a reduction of load.
IOW, what goes up doesn't necessarily come back down as far as you would expect,
and what goes down doesn't necessarily come back up as far as you would expect.

In fact if one assumes that the condition you note is present every time and the hitch returns the fender height to or past its original height it has had to exert even greater force to do so. That component is called weight transfer.---

If you use the tongue jack to raise the rear of the TV, you are applying a "negative tongue weight" to the hitch.
Just as a positive tongue weight removes load from the TV's front axle,
a negative tongue weight will add load to the front axle.
When load is added to the front axle, the front end will drop below the unloaded height.

When the Andersen's chains are tensioned and the tongue jack is retracted, load will be removed from the front axle.
How much load will be removed depends on how much tension has been applied to the chains.
Regardless of how much load is removed, suspension hysteresis (stiction effect) will prevent the front from rising as high as the net load would otherwise dictate.

Application of WD might have restored the front axle to its unhitched load,
but the front end could remain below its unhitched height due to hysteresis/stiction.
This could cause one to conclude there was more load transfer than actually occurred.

OTOH, if you do not use the tongue jack to raise the rear prior to applying tension to the chains,
the front end would initially rise and then be lowered by application of load distribution.
In this case, the front end would "hang up" a bit and one might conclude that the load transfer was less than actual.

In summary, if you raise the rear of the TV with the tongue jack and use fender heights to infer load transfer, you probably are overestimating how much load is being transferred.
If you do not use the tongue jack, you probably are underestimating load transfer.

If you really want to know how much load is being transferred -- use a scales.

Ron

[crisen]

I'll probably regret saying anything on this fender height vs scale weight issue but I have spent a lot of time doing just this when setting up race car chassis. A couple points from my background -
1- The friction in the suspension bushings do effect how the suspensions settles out after making a change to ride height, rubber bushings are very bad for this but race cars use solid bushings in most cases so it isn't too bad to shake out the suspension before taking a reading.
2-To set corner weights accurately the shocks have a big effect and must be disconnected. Gas filled shocks are worst for this.
3- Having considered 1 and 2 above IF you can get the suspension to settle out correctly and repeat the ride height measurements on all 4 corners the scale weights will be the same.

It seems to me that one way to do this would be for you drive the vehicle/trailer combination and come back to the same spot then check it fender heights after making a change to the weight transfer bars you can minimize these problems.

In my mind the exact same thing would have to be done if you are using scale weights. If you disconnected the bars and reconnected them while on the scale and took new scale weights without driving the rig to get the suspension to settle out as it will after going down the road you haven't gained any accuracy over using the fender method.

[Ron Gratz]

Originally Posted by crisen

In my mind the exact same thing would have to be done if you are using scale weights. If you disconnected the bars and reconnected them while on the scale and took new scale weights without driving the rig to get the suspension to settle out as it will after going down the road you haven't gained any accuracy over using the fender method.

Rick, I think I understand your rationale as it applies to height/load for an individual wheel.

However, I believe the combined left + right wheel load on a given axle of a typical tow vehicle is not affected by a friction-related change in ride height.

Ron

[crisen]

Originally Posted by Ron Gratz

Rick, I think I understand your rationale as it applies to height/load for an individual wheel.

However, I believe the combined left + right wheel load on a given axle of a typical tow vehicle is not affected by a friction-related change in ride height.
Ron

I'm not sure if this helps or not but on a chassis setup if you change the ride height of one wheel only, two thing happen, that wheel gets heavier and the diagonally opposite wheel gets heavier and this weight comes from the two diagonal wheels but it doesn't come off those evenly.


I believe you have two things going with a WD hitch, the weight that is transfered by the loading on the reciever and the weight transfer that takes place by the change in ride height. Again by my experience only, the latter is always there so I believe it affects the scale readings as surely as the reciever induced weight transfer.

I guess that one could test the theory by doing it both ways on the scale. Weigh all three axles on the scale w/o weight transfer, don't move the rig, apply weight transfer and re-weigh without moving the rig and then drive the rig to settle it out and weight for the third time without changing the bars. I haven't done this so can't swear to it but if I had access to a scale to set up the trailer I'd make darn sure the suspension was neutral from any friction/shock effects.

[AirHeadsRus]

Ron Gratz and Crisen.
Why don't you two start a "Theory of Weight Distribution Hitch" thread and un hijack this one. Maybe a mod could clean up your posts and move them over to the new one.
Regards,
Joe

[SteveH]

I find it interesting the argument that front fender height measurements are not acceptable because of hysteresis, and all sorts of other "drawing at straws" arguments to po-po the Andersen hitch.

However these same front fender height measurements have been used for years with bar type weight distribution hitches, and somehow it was acceptable with them. I personally have always used fender height measurements to setup weight distribution hitches for 40 years with good success.

I suspect some folks may have an adjenda that is biased against ANY new developments in hitch design, or maybe worse, are employed by some other hitch manufacturer to talk down the Andersen.

[Ron Gratz]

Originally Posted by AirHeadsRus

Ron Gratz and Crisen.
Why don't you two start a "Theory of Weight Distribution Hitch" thread and un hijack this one.---

Joe, I agree this sidetrack has gone far enough.

This line of discussion was precipitated by the assertion:

"If the height is the same, the weight is the same."

I think that claim now has been thoroughly debunked.

Ron