Batmovan
Virginia
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Thanks for the list of definitions Thomas. But as you indicated, it doesn’t really clear things up does it?
If I had to choose one of the given definitions from Ron with my knowledge gained by this thread I would defiantly have to go with #2.
1) The WD system distributes tongue weight over both the front and rear axle (that is the purpose of it), and No indication that changing the TT’s COG would/could put more weight on the TT’s axel or axels.
2) The WD system removes load from the TV's rear axle and distributes it to the TV's front axle and to the TT's axles. Hitch weight is what is truly distributed and taking weight off of the TV’s rear axel is what the desired effect of the design is.
Is this the jist of it or do I need to go back and reread the thread? I have been busier than a centipede with athlete’s foot at work and have not read this post with the diligence I would like to have. It took me several days to catch up with you all (if I have).
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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thomas malenich
sound beach, new york 11789
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Quote:Thanks for the list of definitions Thomas. But as you indicated, it doesn’t really clear things up does it?
No it does not. You can see how the definitions vary. Some say "distribute tongue weight", some say "transfers hitch weight", some say "tongue and hitch weight are the same", some mention distributing some of the load to the TT axle(s) and some do not, and only some mention that the WD system increases the capacity of the receiver or reduces hitch weight.
If I had to choose one of the given definitions from Ron with my knowledge gained by this thread I would defiantly have to go with #2.
1) The WD system distributes tongue weight over both the front and rear axle (that is the purpose of it), and No indication that changing the TT’s COG would/could put more weight on the TT’s axel or axels. Can also be interpreted to mean that tongue weight decreases or that tongue weight is removed from the tongue and distributed......
2) The WD system removes load from the TV's rear axle and distributes it to the TV's front axle and to the TT's axles. Hitch weight is what is truly distributed and taking weight off of the TV’s rear axel is what the desired effect of the design is.
Is this the jist of it or do I need to go back and reread the thread? I have been busier than a centipede with athlete’s foot at work and have not read this post with the diligence I would like to have. It took me several days to catch up with you all (if I have).
Here is the jist of the post in a nutshell: Ron did a wonderful job in describing HOW a weight distribution sytem works. He noted that the load on the receiver was reduced, but went on to say that tongue weight does not get distributed. I thought that it did, but I was proved wrong. I tried to explain that many of the definitions, and the way that senior members speak about WD systems can be confusing. I pointed out that saying that "the WD system distributes tongue weight" can be misinterpreted. Most agree with me on that. From there a definition was proposed and it has evolved a bit as everyone tries to improve on it. The last point I made was that we should all consider the importance of hitch load reduction as part of the definition to read something like this :
A weight distribution system enables a tow vehicle to more effectively handle the tongue weight of a trailer by removing some of the load from the tow vehicle's rear axle and distributing it to the tow vehicle's front axle and the trailer's axle(s). A weight distribution system also increases the capacity of the receiver. Note: When the WD system is engaged the actual tongue weight does not change.
Hope this helps.
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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tluxon
Kirkland, WA
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It all comes down to a basic understanding of elementary physics. To maintain equilibrium, every action must have an opposite and equal reaction. This goes for forces as well, and we assume that the gravitational loading remains static (if the gravitational loading is changing it would be nearly impossible to evaluate!). All the WD system does is re-arrange how the gravitational loading is reacted to by the ground.
With just that basic understanding, I don't don't believe it would be appropriate to interpret "distributes tongue weight" to mean "changes gravitational loading", which is essentially what the opposing argument in this thread is worried about.
I'm going camping - have a great weekend!
* This post was
edited 09/03/04 10:01am by tluxon *
Tim -
wife Beverly & 2 boys who love camping
2002 K2500 Suburban 8.1L 4.10 Prodigy
2005 Sunnybrook 30FKS HP Dual Cam
Replaced 2000 Sunnybrook 26FK on 8/6/04
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Batmovan
Virginia
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All the WD system does is re-arrange how the gravitational loading is reacted to by the ground.
![/quote]
Use that :W
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thomas malenich
sound beach, new york 11789
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[quote]All the WD system does is re-arrange how the gravitational loading is reacted to by the ground.
[/quote]
Use that :W[/quote]
OK - You talked me into it. Lets use that. At least it does'nt mention "distribute tongue weight" :p :W
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4runnerguy
Glenwood Springs, CO
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OK, I found this topic last night and it's kept me awake thinking about it. So here's my 2 cents worth.
First let me say I don't disagree in general with Ron or his calculations. But perhaps manufacturers should call them Weight Redistributing Hitches!
One interesting result of some of the calculations on the first couple of pages is that while the vertical load on the receiver was reduced by 300# (using Rons diagram), it was increased by the weight of the WDH (150# in some examples given there). So when compared to a setup without a WDH, the receiver only sees a decrease of 150# (From 650# without the WDH) to 500# (800# "hitch load" less the 300# "up force" from the bar leverage). I wanted to point this out so people don't over estimate their receivers capabilities with a WDH. (Or am I missing something here. My statics class was way to long ago and they've even changed the course number since then!)
Quote:The WD hitch does not redistribute any weights.
Quote:Weight distrubtion bars simply change where the tongue weight of the trailer gets applied to the ground. It does not change the tongue weight.
This is a very important point and really gets to the root of some of the problems debated here. Prior to being hooked together, there are typically four main bearing points on the ground: the TV front axle, TV rear axle, the tongue support, and the trailer axle(s). Once the trailer is hooked up, there are three (no tongue support). At that point, from the grounds point of view, the tongue weight has been distributed to the TV axles (of course the rear increases and the front decreases). Once the WDH bars are in place, the tongue weight (again from the grounds point of view) has been redistributed between the TV axles and the TT axle(s).
Now of course it can be instructive to use examples of zero tongue weight and show that the WDH simply distributes the load from the TV rear axle to the TV front axle and TT axle(s) (and that is true), but the reason people who read this forum are interested in WDH is because a heavy tongue weight has overloaded the rear TV axle (and underloaded the front). While confusion can arise from someone who interprets "distributes tongue weight" to mean removes tongue weight, in practical real life situations, the load that is being removed from the rear axle by the WDH is being placed there primarily by the TT tongue weight.
When I was doing some additional research on this subject, I found an interesting definition on the Draw-Tite website:
"(W)eight distributing hitches apply leverage between the towing vehicle and trailer causing the TW to be carried by all axles of the tow vehicle and trailer. When TW is distributed in this way, trailers with greater TWs can be towed, resulting in a more level ride which reduces stress on the rear of the tow vehicle and provides greater steering and brake control." (TW=Tongue Weight)
This definition seems to me to be as good as anything else I've seen and hopefully doesn't cause confusion about decreasing tongue weight.
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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Steveque
Central California
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Well,
My wife and I spent almost three hours this past Saturday with a tape measure and wrenches putting our new Dual Cam system on. We then had to move the ball up two holes which meant changing which way the receiver bar was postioned. Got a lot of practice backing up and hooking up. My TT is almost parallel front to back as measured from my driveway. My TV sits at the same height in the front but almost 1 inch lower in the rear. My Tahoe has such a soft rear suspension that the TT settles it down about 3 inches without the WD bars set and only 1 inch with. The math that has gone on in this discussion has been great but I'm sure the weight of the TT tongue that sits on the ball of my TV is actually less than before since I now have the TT riding parallel to the ground. With this move, the energy required to hook up the WD bars is less than before. In a few weeks the TT and TV will do a trial spin of a few miles to verify the cost of equipment and time spent.
Steve Quesenberry
Central California
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tluxon
Kirkland, WA
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Quote:4runnerguy wrote:
When I was doing some additional research on this subject, I found an interesting definition on the Draw-Tite website:
"(W)eight distributing hitches apply leverage between the towing vehicle and trailer causing the TW to be carried by all axles of the tow vehicle and trailer. When TW is distributed in this way, trailers with greater TWs can be towed, resulting in a more level ride which reduces stress on the rear of the tow vehicle and provides greater steering and brake control." (TW=Tongue Weight)
This definition seems to me to be as good as anything else I've seen and hopefully doesn't cause confusion about decreasing tongue weight.
We're back from a great weekend in the RV and I was sure I'd come back to several more pages of discussion in this thread. Instead, I'm quite impressed to find that it looks like the loop is closing and we're almost finished re-inventing the proverbial wheel. It'll be interesting to see Ron's response to what has transpired since he left.
Being an engineer myself, I'm amused by the picture of some Draw-Tite engineer being approached by a marketing guy with the task of coming up with their company's "official" description. There are definitely a lot of nuances to the WD hitch which if taken literally can be very confusing, yet a concise and simple definition had to be derived. Preferring these guys to be the "hitch experts", I really like the Draw-Tite definition that 4runnerguy found, even though it has the potentially confusing phrase, "TW is distributed". Perhaps us concerned end users could modify it to "TW is distributed (in effect)".
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thomas malenich
sound beach, new york 11789
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Hi Tim,
Just could not continue without you or Ron or #20 HomeDepot. Hope you had a great and restful weekend.
I have plans for a new topic but need more input from all. What is your definition of tongue weight? Please be specific about what you think is important to understand about tongue weight as it relates to a WD system.
Thanks, Tom
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tluxon
Kirkland, WA
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Hi Tom,
I had always simply taken a trailer's "tongue weight" to be the difference between the total weight and the weight borne by the axle(s). That's certainly the way RV manufacturers use it. However, your question made me think about it a little more and I'm not so sure if that's the best definition in the context of our discussions. As soon as we mention "borne by the axle(s)", we're talking about the ground's reaction through the axles, which, as we've clearly illustrated in this thread, is changed by a WD system.
I think instead that the unchanging "tongue weight" that we've discussed would have to be described in terms of gravitational mass, but I'm not sure that there's a simple way to characterize the remaining mass that's not centered over the axle(s).
Care to take a stab at it?
Thanks for the brain ponder. ![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/eek.gif "eek")
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