thomas malenich
sound beach, new york 11789
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Joined: 08/29/2003
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Ron,
I would like to take this opportunity to thank you for this thread. Your work, insight, and knowledge are greatly appreciated. I have thoroughly enjoyed the debates and light-hearted jabs. I have learned alot from you and as much from the other members who participated in this thread. I know that I flipped and flopped, but I was only trying to argue my points at a given time and my perspective changed vastly throughout.
I re-read the entire thread yesterday and it was like watching a good movie a second time. You know - you always miss something the first time.
Thanks again Ron, and a special thanks to Barney for tolerating us and allowing the thread to run its course.
Tom
Thomas and Laura Malenich
1988 Suburban 1500, 4WD
Scotty 16 1/2' , smaller and loving it
2 kids and 3 dogs
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4runnerguy
Glenwood Springs, CO
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Joined: 03/10/2003
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Welcome back Ron. I kind of resurrected this thread after you had left. I only got to fish for three days over Labor Day weekend. You must be so relaxed you just melt in your chair.
In my more recent posts, I have tried to emphasize a couple of times that a light tongue weight is not the specific cause of sway. It is a reflection of an improperly loaded (or improperly balanced) trailer. That is what is critical for a newbie to understand. As I will discuss below, I don't know that "Tongue Weight" is a valid terminology or concept once a WDH is hooked up.
As I understand the general use of the term "Tongue Weight" in the manufacturers literature, it is that portion of the trailer weight that doesn't rest on the axle(s), when the trailer is level and disconnected from a vehicle. As you know, the tongue weight is a function of the position of a number of loads distributed over the trailer frame, axles, and tongue. As more weight is applied ahead of the axle, the center of gravity shifts forward and a greater percentage of the total weight is on the tongue.
When the trailer is hooked up to a TV, essentially all of that tongue weight is applied to the ball, subject to slight differences if the trailer isn't level because of sag, etc. I think we would all agree on that point. But once you hook up the WDH bars, defining tongue weight becomes difficult.
The weight on the trailer axle(s) has increased. You noted: "The down force is less than the up force due to the load transferred to the TT's axles." You have previously defined Tongue Weight as: "Tongue Weight: That portion of the TT weight which is carried on the ball coupler as opposed to that carried on the axles". Using your own definition, once the WDH is hooked up the tongue weight must decrease since the weight on the rear axle has increased.
We could go around and around debating this, and I have read over and over all of the debate here. In my opinion, once the WDH bars are hooked up, tongue weight is not a readily determined value using the standard definitions. Nor is it a particularly useful concept at that point. The loads which created the tongue weight when the trailer was disconnected are still at the same place, but because of the WDH, the trailer axle now has additional loading, and there are now new forces and geometries involved where the bars attached to the tongue.
I have difficulty when you answer your last question saying the tongue weight doesn't change based on the foregoing. I think a better answer might be something like:
NM: I’ve heard you need a certain amount of tongue weight for sway stability. Does the WD hitch change the tongue weight?
SM: Please realize that the tongue weight is a reflection of the way your trailer is loaded. Before the trailer is hooked up, the tongue should carry 12% to 15% of the total trailer weight. The WD hitch simply changes the way the total weight of TV and TT is carried by the TV and TT axles and does not change the weight distribution of your trailer.
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By the way, I don't think we should push someone to use a WDH without a caveat regarding the suitability for their particular trailer and TV. I don't use one because my owners manual specifically advises against it. I would no more disregard that statement from the manufacturer than I would ignore the tow rating of the vehicle.
Ken & Allison
2 Camping Cats (1 diabetic)
1996 4Runner, TRD Supercharger, Edelbrock headers
2007 Fleetwood Arcadia, Honda EU2000i
4 mountain bikes, 1 canoe, 4 tents, 8 sleeping bags, 2 backpacks
(You get the idea!)
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Oasisbob
Portland Oregon 97266
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Joined: 11/18/2001
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Do I understand you to say your Bantam factory book advises against load leveler bars or am I reading you wrong? I am buying a Bantam B-19 tomorrow and it has no owners book. Do they suggest sway bars ?
Thanks
Oasis Bob
Wonderful wife 3 of 4 kids at home. 1 proudly serving in USAF
2018 Ford Explorer
2001 Bantam Trail Lite B-19
HAPPY TRAILS">
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4runnerguy
Glenwood Springs, CO
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Oasis Bob-
Sorry, it was late at night when I wrote that. I should have been more specific. It is the 4Runner that advises against using the WDH. But I would check the minivan owners manual. Often unibody vehicles advise against using the WDH because of the stresses they place on the vehicle.
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Batmovan
Virginia
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Joined: 06/29/2004
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Remember the K.I.S.S. method? These are newbies who just want some basic facts for the purpose of deciding on, hooking up and using a WD hitch. Maybe the generic tongue weight term is fine. However if we think tonge weight is core to the idea I suggest we define Tongue, Ball and Hitch weight. We could then expand each question using those terms. The question and answer idea is a good one Ron; it is simple and to the point. Like this thread? ![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/wink.gif "wink")
NM: Do I need a WD hitch?
SM: If your trailer’s ball/tounge weight is causing the back end of the vehicle to sag, a weight distributing hitch can be used to return the vehicle to its normal height. Consult your owner’s manual to determine if your vehicle is suited for a WD hitch.
NM: Why do I need a WD hitch?
SM: , When you hook your TT to your TV, the TT’s ball/tongue weight on the hitch causes an increased load on the TV’s rear axle and a decreased load on the TV’s front axle this may also cause your trailer’s COG to be effected .
NM: Why is that bad?
SM: The increased rear axle load might exceed that axle’s load rating. Perhaps more importantly, the decreased front axle load might cause diminished steering response and braking action of both TV and TT.
NM: How does the WD hitch change that?
SM: The WD hitch redistributes the amount of load carried on each of the TV and TT axles. The
TV’s rear axle load is decreased and the TV’s front axle load and the TT’s axle(s) load are increased thus helping in leveling the TV and TT.
NM: I’ve heard you need a certain amount of tongue weight for sway stability. Does the WD hitch change the tongue weight?
SM: No, the tongue weight remains the same. The WD hitch simply changes the way the total weight of the TV and TT is carried by the TV and TT axles.
This is still my favorite.
Quote:Ron and I hitch up his trailer. The rear of the truck sits way low, the front is way high, and the front wheels don't steer or brake worth a darn 'cuz of this.
We stick a long pry bar into the back end of his truck frame and pull up hard. The rear rises and the front drops. I have Ron trot along holding that bar up as I drive...the truck drives really well now, but Ron is getting tired. He chains the bar to the trailer tongue so he can take a breather. This works OK on the straights, but is a big problem on curves. We figure out a pivot system for the point the bar attaches to the truck. It turns well, but is really bumpy. Ron's Mrs. says to use spring steel bars. Duh!...Why didn't we think of that? Ron and I, and his Mrs., just invented the weight distributing hitch.
Ken
Ford E350
7.3L Diesel: Six Gun, Transcommand, K&N, Apillar guages, Prodigy
GVWR: 8,700, GCWR: 16,000
Jayco 31Bhs, Reese Dual Cam HP
Wife and six children (1 set of triplets)
Dubbed the "BATMOVAN" by my 8 year old
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Ron Gratz
full time RVer
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Joined: 12/27/2003
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Quote:--- You have previously defined Tongue Weight as: "Tongue Weight: That portion of the TT weight which is carried on the ball coupler as opposed to that carried on the axles". Using your own definition, once the WDH is hooked up the tongue weight must decrease since the weight on the rear axle has increased.
Hello Ken,
Thanks for your contributions to the thread.
My definition of "tongue weight", Tongue Weight and Hitch Load - What are they and how are they different?, differentiates between WEIGHT of the TT and EXTERNAL FORCES on the TT. The definition states:
"If the weight of the hitch assembly is neglected, tongue weight is numerically equivalent to hitch load when there are no forces other than the TT's weight acting on the TT. If there are other vertical forces acting, then the values will be different."
and
"An example of other forces are those imposed on the TT by a WD bar tensioner."
My whole objective in proposing different definitions for "tongue weight" and "hitch load" was to have a definition by which "tongue weight" does NOT change when the WD bars are tensioned. Tongue weight, by this definition and when expressed as a percentage, is a measure of the relative location of the TT's center of gravity. As such, tongue weight is an important consideration for determining sway stability.
Quote:By the way, I don't think we should push someone to use a WDH without a caveat regarding the suitability for their particular trailer and TV.
I fully agree. I had considered adding the words, "where appropriate", to my proposed response to New Member. I will edit that post to include those words.
Ron
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4runnerguy
Glenwood Springs, CO
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Joined: 03/10/2003
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Ron-
Before I comment on your comment on my comment on your comment on . . . ![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/smile.gif "smile")
I made a statement earlier that WDH by themselves do little to eliminate sway. But maybe they do. With the application of a 2000# load 30" from the ball coupler (as in your example), it does move the center of gravity of the TT forward. I must assume that this should help eliminate sway to some degree, since sway is a function of the position of all of the loads on the trailer in front of and behind the TT axle. (The mechanics of sway don't separate the distribution of the trailer weight from any other load applied to the frame.) Is that true?
I guess I should try to do more of my brainstorming in the light of day rather than the middle of the night as I sometimes do. I look back at some of my posts as less than clear and maybe contradictory. Sorry.
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Ron Gratz
full time RVer
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Joined: 12/27/2003
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Quote:--- With the application of a 2000# load 30" from the ball coupler (as in your example), it does move the center of gravity of the TT forward. ---
Ken, this statement is true if the 2000# LOAD results from placing some MASS weighing 2000# at that location. The statement is not true if the 2000# LOAD results from TENSION in the spring bar tensioners. The CG of the TT can be moved only by adding or removing mass or by moving some of the existing mass.
Such confusion about loads resulting from mass versus loads resulting from other effects is the reason I am trying to avoid the use of the term "weight distribution" and its counterparts. If one is told that a WD hitch "distributes weight", and if one knows that "redistributing weight" can result in a change in location of the CG, then it is not illogical to incorrectly conclude that application of a WD hitch can move the CG. The problem stems from inconsistent definitions.
Quote:I must assume that this should help eliminate sway to some degree, since sway is a function of the position of all of the loads on the trailer in front of and behind the TT axle. (The mechanics of sway don't separate the distribution of the trailer weight from any other load applied to the frame.) Is that true?
The mechanics of sway are determined primarily by horizontal forces on the TT. When a mass is accelerated horizontally, a horizontal force results. Weight, per se, is not involved directly because weight is a vertical force (that comment ought to precipitate another 150 posts). Weight on the TT tires indirectly influences TT sway because it, among other things, determines how much horizontal force the tires can generate.
WD hitch forces are not involved directly in TT sway dynamics because they are vertical forces. However, changes in TV axle loads can have a significant effect on TV/TT sway dynamics primarily due to changes in steering response. The vertical load on the tires determines how much horizontal force the tires can generate.
Is this any clearer or have I only added to the confusion?
Ron
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thomas malenich
sound beach, new york 11789
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Joined: 08/29/2003
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Such confusion about loads resulting from mass versus loads resulting from other effects is the reason I am trying to avoid the use of the term "weight distribution" and its counterparts.
____________________________________________________________________
Ron,
I hear you. We all went through that a while back. I once suggested that we should consider not using the term "tongue weight" once the tongue is hooked to a TV and no longer supported by the tongue jack.
Unfortunately the manufacturers use words such as "weight distribution", and "distributes tongue weight", and "the rear axle bears much of the tongue weight". We can not fight them.
I feel that we can provide the best service to the new members using the ORF search, by providing a definition/summary consistent with the manufacturers, yet enlightening.
That is why I wrote my summary using a blend of manufacturers wording and our/my wording.
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thomas malenich
sound beach, new york 11789
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WD hitch forces are not involved directly in TT sway dynamics because they are vertical forces. However, changes in TV axle loads can have a significant effect on TV/TT sway dynamics primarily due to changes in steering response. The vertical load on the tires determines how much horizontal force the tires can generate.
___________________________________________________________________
We can conclude that the WD hitch can be "indirectly" involved in TT sway dynamics, since the WD hitch is responsible for changes in TV axle loads.
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