E&J push'n wind wrote:
4X4Dodger wrote:
E&JPNW wrote: "Now place a 25' to 35' trailer with all of its weight and the lever it has between the center line of the axle assembly and the tongue coupler. I wish I knew how to place illistrations on here, I will try to paint a word picture. Picture an arrow pointing at the pivot point in a lateral fashon at both a 5th wheel hitch and a conventional hitch. This of course is latter force. Sure 5th wheel hitches have lateral force exerted against them. The difference is that because of its placement over the center line of the rear axle (or slightly forward of it) you lose the lever effect that a conventional hitch would exert against the TV because of its distance from the center line of the rear axle."
Answer:
I believe you are thinking in only one plane. The ball hitch is either equal to or BELOW the frame of the truck. this position is much more difficult to move the truck on a lateral plane than the 5th wheel.
I'm speaking in terms of through the length of the vehicle, not the height of the vehicle. You will be able to rock it in a "fish tail" motion. You will not be able to as effectively with a 5th wheel hitch.
I've got to ask the question, what are you thinking of when we use the term, "lateral force?" My understanding is, a force from the side in some fashion, again through the length of the vehicle on a horizontal plane. So yes, for the sake of our discussion I am thinking in only one plane as these are the forces exerted from a sway condition.
The 5th wheel is much higher ABOVE the frame with most of the trailer weight still above that to act as a lever against the 5th wheel and the frame. This equals a longer lever arm = more force. Thus you need that big plate of the 5th wheel to react out those forces down thru the frame.
In this picture, you are looking at this from a vertical plane, top down through the fifth wheel. I believe what you are describing is pitch. A vertical side to side leaning. If you are understand this to be sway, then I can certainly understand your dilemma as an anti sway device would certainly NOT not help in any way resolve this condition.
But this has little to do with TRAILER sway. What you are talking about would be the trailer swaying the TV. If the TV is doing its job and the rig is set up correctly that's not going to happen (except in extreme cases of out of control stops or similar)
Answer this simple physics question for me:
Tell me what two principals of Physics are represented by the HAND CART? (the two wheeled upright kind)
I don't ask this to embarrass you but to understand and hopefully show you that the physics you believe are reacting on the TV just aren't correct.
4X4Dodger, I'm not embarrassed. I've explained that I'm not an engineer and I'll add, neither a physicist. All due respect to you, I suspect neither are you, though I could be wrong. I think if you were, we would have a mathematical explanation of your hypothesis. I've seen/read comments on this forum from engineers and they are very descriptive in their scientific language and explanation of things. You and I are having a time of it trying to describe our point of view.
So.., I'll ask you to explain yourself with the hand cart principal and ask you how that applies to what we are talking about for me and the sake of other readers.
Think about this by looking at the design of most of these sway bar systems, they simply react out the forces of the trailer's side to side motion by exerting a countervailing force against the tongue. NOT THE TV. If your hypothesis were correct all that bar and chain mechanism that works against the trailer would be aimed FORWARD.
They work in unison on a lateral plain. At the risk of starting a fire storm, the premimum namely the HA and PP are designed so that the trailer CANNOT turn (sway) unless there is input from the TV. I invite you to look at the sticky in the travel trailer section on the HA and how it works. The other conventional hitches typically use friction of some sort to counteract a sway condition where the trailer is whipping side to side. Kind of like fish tailing in a manner of speaking. The difference between the conventional friction type is that friction can be overcome. With a PP or HA, if the hitch is in tension it shouldn't be able to. In theory the whole unit (TV & TT) would move as a unit.
E&J: "I'm not saying that there arent lateral forces on a fifth wheel hitch, I'm saying there isn't leverage in the same manner as a conventional hitch."
Answer: leverage is leverage it changes with the length of the lever. Not with the hitch type. If anything the 5th wheel is able to exert MORE leverage than the ball type.
Please explain? On a horizontal plane where a 5th wheel is able to exert more leverage? Am I missing something?
4X4Dodger, I've asked this question before and you still have yet to answer it. Please describe (on a horizontal pane) the leverage in relation to a 5th wheel hitch? I can't see it, unless I'm missing something. I've described I think quite clearly the leverage in relation to a conventional hitch on a horizontal plane. Unless we are on different terms (and I think we are), lateral to me is on a horizontal plane.
5th wheels are placed over the axles PRIMARILY for WEIGHT reasons. This takes advantage of the Carrying capacity of the P/u. There MAY be some advantages of stability (but not if the trailer is loaded wrong) but the reason 5th wheel travel trailers were designed in the first place was to provide a much bigger trailer (with a much higher tongue weight) to meet consumer demand for more space and amenities...it was not to reduce sway.
My conclusions from looking closely at these hitches and thinking deeply about the problem:
The VAST MAJORITY of sway problems are driver induced or improperly loaded trailers (same thing really)
Sway bars were a response to a lucrative market niche of the above that wanted to have a mechanism that damps out their inputs.
"Sway bars" better described as equalizing bars or weight distribution bars/spring bars. If your idea of these is as I suspect, then you have a misunderstanding of what the function of these bars are for. As I have just more accurately described them, the PRIMARY purpose for these bars was originally to distribute weight between the TV and TT. Over the course of the evolution of these spring bars sway control has been incorporated into the design.
More often than not, a 1 ton or even a 3/4 ton truck will not need these bars to tow a TT as they have sufficient suspension to "carry" the weight of a given TT. Reality is there are more 1/2 ton TV (P/U's and SUV's) on the road than their larger counterpart TV's. This is where the weight distribution are absolutely necessary to properly carry a said tongue weight. Without these spring bars it would be very unsafe to tow these trailers though it is done by unwitting folks.
Again, at the risk of starting a firestorm. The HA and PP hitches have sway control incorporated into the design of the hitch. you can tow without the spring bars and still have the added benefit of sway control (horizontal plane). Many (not all) of the friction type sway control conventional hitches NEED the spring bars as this is part of the source of friction.
While this product may have it's benefits under certain road conditions and driving conditions (driver input) They are NOT NECESSARY to haul a trailer safely.
If you have a 1 ton or in many cases 3/4 ton truck, I think you'd be hard pressed to get an argument. However, look in the owners manual of vehicles that are designed to tow in some capacity and they will state that you need a weight distribution hitch to tow weights greater than X. These hitches that you are adamant about not needing and blantantly stating are not a safety device is quite irresponsible IMHO. For someone to read this and view you as an "authority" (yep they are out there) puts them at risk and everyone around them.
We have two things that we are talking about. 1) anti sway device, and 2) (I bring up) weight distribution. While they are not necessarily one and the same, in many instances they are simply because this is how the MFG's have decided to make them. With a conventional hitch you can have one without the other, you have to know what you are getting. I will state that having a weight distribution hitch may be necessary depending on the TV and the trailer behind the TV. While it is good to have and can be a safety device, sway control may not be absolutely necessary. Again, this depends on a lot of factors including the size of the TV & TT, loading of TT, hitch arangement, driving conditions etc.
Dont expect Trailer Life or its editors to ever print a fair article on this subject as there is just too much money at stake. TL is owned by Good Sam Ent. and so is Camping World. A great deal of income is derived from the Advertising and sales of these hitches by the GS Enterprises companies.
Playing the devils advocate, do you have anything to substantiate your claim? While I'm sure they derive revenue from advertising, and perhaps sales, you make a pretty bold claim without any proof. You are accusing them of the very thing you are doing, making claims without any proof. Hitch sales, really?
Unless and until an independent third party similar to consumer reports does some real scientific testing on these products and draws a conclusion one way or the other I will remain a healthy skeptic.
To all of those that use them and believe in them this is certainly your prerogative. But I think you should exercise some care in claiming that they are a SAFETY device. I don't believe that has ever been proven...
And while your stories of roll-overs and radically swaying trailers are compelling they remain only ANECDOTAL evidence...without real investigation, rather than a lot of assumptions of what really happened.
But one of the most telling things for me is this. The people who owned my trailer before me used one of these hitches and it came with the trailer. I have never bothered to assemble it or use it and I have absolutely no sway problem with driving this trailer. In fact my first trip with this trailer was Chicago to Minot ND (over 1000 miles) during one of the worst wind and snow storms of the season...and NO SWAY. Much of the time roads were snow and ice covered and the wind blew as much as 40 MPH and more..
All due respect 4X4Dodger, what's the difference between your anecdotal story and another. Should yours carry more weight because you feel so strongly about it? Also, to your point about it not being proven. It hasn't been dis-proven either.
edited by author for clarity
You make some good points and some valid ones. I wont bore you or other readers with my resume here I will PM you with some further info on that. Nor will I try to put the math down here...that is a useless exercise as most will be bored to tears with it and in the end it wont prove anything or change anyone's mind. Thse that understand it, already get what I am saying...those that dont the math will not help. However this conversation is getting too long and cumbersome. I will try to address your main points:
First: Weight Distribution and Sway are two different animals. However one can affect the other. We are talking about SWAY. And the mechanisms sold to as one manufacturer claims "eliminate it 100%"
Second: I do not feel strongly about this issue as I have said many times I am HIGHLY SKEPTICAL and have seen no proof that they do what they claim they do...meanwhile people are elevating them to the status of a NECESSARY SAFETY device. This I see as irresponsible and very possibly dangerous.
Third: The 5th Wheel and lateral forces; (for lack of a better descriptor) The one to two foot height that a 5th wheel sits above the frame of the vehicle is basically a Lever Arm for the trailer to use. This distance magnifies the forces. Downward, sideways (lateral) and along the longitudinal axis of the vehicle. These forces will RESULT in things like Yaw Pitch and Roll (same as an aircraft) upon the vehicle. The forces are reacted out by the TV and it's suspension (in most cases).
Fourth: you must take into account the Height at which the forces are applied as well as on which plane (in this case) This relates to the CG's of the individual vehicles and their combined CG. But again this has more to do with Weight Distribution and stability than it does with Sway.
Fifth: You Wrote;
If you have a 1 ton or in many cases 3/4 ton truck, I think you'd be hard pressed to get an argument. However, look in the owners manual of vehicles that are designed to tow in some capacity and they will state that you need a weight distribution hitch to tow weights greater than X. These hitches that you are adamant about not needing and blantantly stating are not a safety device is quite irresponsible IMHO. For someone to read this and view you as an "authority" (yep they are out there) puts them at risk and everyone around them.
You have misquoted be badly. I have never claimed they are not needed in some applications. Nor have I put myself up as an authority. What I am is VERY Skeptical in the face of an overwhelming lack of any evidence from a reliable third party having tested these products and come to some conclusions about what they really do and how effective they are. And yes some Mfgs do recommend a Weight Distributing Hitch for certain vehicles...NOT an Anti Sway system. They are two different things (but often combined into one product)
Sixth: I wish that we could depend on Trailer Life to put these things through a rigorous testing program with a reliable Auto testing Lab. But it will not happen in my view. To repeat what I said above; TL sells Tens of thousands of dollars in advertising space to the MFG's every year. Camping World sells them and installs them. Both companies are wholly owned subsidiaries of Good Sam Enterprises. They all have the same CEO (Marcus Lemonis) To expect this company to put public interest above their bottom line and piss off one of their major advertisers is...well frankly...naive. This is not to say that GSE is an evil company, I dont beleive that for a moment. But it is very mindful of who butters it's bread. So why take a chance on killing the Golden Goose so to speak. And this is admittedly not the largest advertiser or source of sales revenue for the company but it is SIGNIFICANT.
To the handcart question: The handcart or Dolly represents the Lever and the Inclined Plane. I will PM you on this. I was merely trying to find a way to better illustrate a part of physics that relates to this problem. My apologies if I offended you in any way it was not my intention.
Try to visualize this: take a toy tractor trailer, remove all of the friction that is present under the tires. Put your finger on the far back edge of the trailer and apply force (PUSH) sideways. What happens? The rear end of the tractor will move LATERALLY in the OPPOSITE direction. This is Newtons Third Law = For every action there is an opposite and equal reaction. This physical law is present in fifth wheels and Ball hitches. It is a lateral force.
BUT let me be very clear. This is not what INDUCES sway. This is the RESULT of sway.
What we need to concentrate on is WHAT CAUSES SWAY. My contention is that the forces that come to play are MOSTLY Driver induced. These products are a result of that driver behaviour and meant to counteract that. I further contend that if driven and loaded properly SWAY is not the huge Bogeyman that it is made out to be. And what we need is a system to train drivers not a mechanism that masks bad habits and that people believe is a SAFETY DEVICE.
