Resuscitate a smashed Airstream or Not?

[Silvertwinkie]

Well, now that the pros have spoken, it appears that if you got the $$, they got the beer!

My vote would be to take whatever insurance gets ya, and find a similar coach and start over...even if you gotta spend some $$ getting up to the standard your old one was at....in the long run, it could be less expensive then repairing your old friend as much as I can understand that might not be what you want to hear.

[RivetED]

Originally Posted by Inland RV Center, In

davidp.


Therefore I doubt that you moved "any" tongue weight, as one "must" do.

With that truck. you should have used the "smallest" rating hitch Reese had which was a 550 pound rating.

Research data, from over 20 years, bears out that you were "grossly" over hitched, and really, you were a predictable accident, looking for a place to
happen.

The fortunate thing however, is that your OK.

Andy

#1: Best thing is you & your passenger are OK.

#2: I'd look for another trailer, sorry.

#3: Without knowing what angle the hitch head is set to or the amount of loading you had on the spring bars I would NOT be comfortable stating that you were grossly over hitched or that no tongue weight was distributed (moved). Hitch head angle, strength of bars, and how many 'links' are used 'move' the tongue weight, this is measurable & adjustable. The trailer should also be as level as possible when hitched. Your tow vehicle is a bit short but there are many factors not in evidence here that can contribute to the accident.

[davidp]

Originally Posted by Ed & Debbie

#3: Without knowing what angle the hitch head is set to or the amount of loading you had on the spring bars I would NOT be comfortable stating that you were grossly over hitched or that no tongue weight was distributed (moved). Hitch head angle, strength of bars, and how many 'links' are used 'move' the tongue weight, this is measurable & adjustable. The trailer should also be as level as possible when hitched. Your tow vehicle is a bit short but there are many factors not in evidence here that can contribute to the accident.

Given Andy's expertise, his recommendation for a smaller hitch is no doubt accurate and is probably a "best practice" moving forward.

That said, I do believe that at least some tongue weight was distributed; the local Airstream dealership hooked it up exactly the same way I was taught when I had it serviced, as did the dealership where my grandparents had it serviced over the years. When hitched, the trailer was quite level; the first time I pulled it I had it weighed to make sure it was in the correct range. My grandfather (an engineer) towed it with a 1979 Ford Econoline conversion van for long trips - even participating in a Caravan through Mexico in the early 1980's. At least a few times for weekend trips he towed it with a 1976 Chevy Silverado; all with the same Reese hitch that I still have and used.

Would the sway control equipment have played a role?

David

[Chuck]

Originally Posted by Inland RV Center, In

What you have (had), is like a Peterbilt tow vehicle with the largest hitch that Reese made.

how is that? is it just the heavy spring bars? I thought he said it was only a half-ton truck...

Originally Posted by Inland RV Center, In

Therefore I doubt that you moved "any" tongue weight, as one "must" do.

How would the rating of the spring bars affect this? I understand how having too stiff a hitch setup could damage the trailer over the long-term, but how do we know that tounge weight wasn't being transferred?

Originally Posted by Inland RV Center, In

With that truck. you should have used the "smallest" rating hitch Reese had which was a 550 pound rating.

we're still talking about spring bar ratings, right?

Originally Posted by Inland RV Center, In

Research data, from over 20 years, bears out that you were "grossly" over hitched, and really, you were a predictable accident, looking for a place to
happen.


Andy

I'm sure the engineering data will be provided in the articles, right? (I'm just teasing; please don't get upset!!! )

seriously...I want to avoid being classified as a "predictable acciedent, looking for a place to happen"...or a statistic.

[RivetED]

Originally Posted by davidp

Given Andy's expertise, his recommendation for a smaller hitch is no doubt accurate...

David

I acquiesce in the face of overwhelming evidence .

[Inland RV Center, In]

Chuck.

In actual road tests, using 1000 pound Reese torsion bars and the Reese "straight line" sway control, with a 1/2, 3/4 and one ton trucks, towing a loaded 31 foot Airstream, demonstated handling problems.

As a rule of thumb, a 1000 pound "dual cam" Reese hitch should be used on larger cars, which are hard to find any more, when towing a 31 foot Airstream trailer.

Same trailer, with a 1/2 ton truck, should use a 750 pound hitch.

Same trailer, with a 3/4 or one ton truck should use a 550 pound hitch.

Why, (very briefly), unless the bars are bending a minimum of and inch or so, (more is superior) the hitch will not provide much sway control.

The harder it becomes for the bars to rise on the saddles, the better the sway control.

One of the devices used during these tests was called "Safety Tow." It was a electrical, automatic sway control, that eliminated a sway by the rapid "automatic" application of the trailer brakes. It might have pulsed the brakes on up to full application.

The sensor was mounted at the very rear of the tow vehicle. The control panel was mounted on the left side of the dash. It had two lights on it. A green and a red.

In normal operation, the green light stayed on.

When "any" degree of towing instability took place, the "red" light would "blink" warning you of that instability.

Using that as a guide, changing different ratings of Reese torsion bars, displayed a huge difference in handling stability. (Refer back to the above recommendations.)

Further tests were made by altering tire pressures. As another example of that devices value, on the loaded test 31 foot Airstream, (mine), tire pressures were set to 60 psi. Dropping the pressure to 50 psi on "ANY" tire, caused the red light to again indicate instability. All four tires, one at a time, had the pressure dropped the ten pounds and at the same time, increasing the pressure on the last test tire, back to 60 psi.

All of us, as we travel, can lull back as we travel the freeways, therefore become unaware of other small changes such as the wind speed and direction.

The Safety Tow, would clearly indicated "instability" when quartering winds or gusty winds were present, suggesting that you reduce speed until stability returned, which it normally did.

In summation, personal opinions were eliminated by using the Safety Tow.

Some 30 years ago, a person by the name of Bob Jubinville, from New Jersey, invented the Safety Tow, and obtained 18 out of the 20 patents that he applied for. Unfortunately, he died shortly thereafter, and his son did not share the same interests as his dad. We sold many Safety Tows, some 30 years ago, but lost track of the son, a long time ago.

Perhaps the time is right for this device to again be on the market. It certainly more than proved it's worth when demostrated at many rallies, long ago.

Typical comments ranged from "wow" to "unbelievable" to "how fast can I get one". It took less than an hour to completely install that unit.

If anyone knows the whereabouts of Jubinville Junior, please lets us know.

The December issue of Airstream Life, will contain even greater details about hitches, rigging, sway conrols and the like.

Hopefully, the above will lay to rest some of the seemingly unanswerable questions about "what is proper rigging" for a load equalizing, full sway control hitch.

Oh yes, the friction type sway controls, all scored low, in actual road tests, compared to the Reese straight line.

Stay tuned.

Andy

[87MH]

Originally Posted by davidp

...The accident was on the freeway, and when things came to a stop the Airstream was on it's side (roadside), jack-knifed against the rear drivers side of the tow vehicle and the rear of the tow vehicle was about a foot off the ground.....

David P

Given what was presented in this thread – and no knowledge of any private correspondence, I would like to offer my views of your setup and subsequent accident with the 2003 Silverado standard cab short bed Tow Vehicle with appropriate tow capacity, the ’77 31’ Airstream Trailer, and the Reese weight distributing hitch.

My comments below pertain only to the information presented in the Forum. No anti-sway device was mentioned (other than Andy's latter posting), so please consider only the information as presented pertinent to the hookup.

Inland RV wrote:

“What you have (had), is like a Peterbilt tow vehicle with the largest hitch that Reese made.”


I would submit that your Silverado was well matched for the 31’ Sovereign – probably even close to the upper limits – but definitely not “overmatched” for the job. When the trailer was put on the ball, you probably observed some rear end squat, which you should have adjusted out with the Reese Weight Distributing Hitch.

Inland RV wrote:

“Therefore I doubt that you moved "any" tongue weight, as one "must" do.”

There is no requirement for transferring any weight at all, as long as the tow vehicle maintains a correct stance after the load of the trailer tongue is applied to the ball. Weight transfer is only necessary to bring a tow vehicle to a proper “stance”. If the rear measurement point (usually the wheel well) lowered, 1”, then a properly set up weight distribution hitch will also provide for a 1” drop (lowering) of the front measurement point. If you were, indeed, towing with a Peterbilt, you probably would have observed absolutely no rear end squat, negating the requirement of a WD hitch.

I assume there was rear end squat, and I further assume that you adjusted the WD hitch to properly “balance” the vehicle. My apologies if these assumptions are in error.

Inland RV wrote:

“With that truck. you should have used the "smallest" rating hitch Reese had which was a 550 pound rating.”

As per the Airstream website, the EMPTY weight of a 31’ ’77 trailer is between 5005 lbs and 5070 lbs with recommended hitch weights ranging between 620 and 715 lbs.

For argument’s sake, let’s assume a conservative case…that the trailer was loaded with only 500 lbs of “stuff” – propane, water, clothing, food, bedding, . Let’s also assume that the driver follows the Airstream published recommendation of carrying between10% to 15% of that weight on the hitch tongue (somewhere between 550 and 760 lbs.).

Then a worst case situation occurs – an accident involving the trailer/tow vehicle combination.


The first thing a litigation attorney will ask in deposition following an accident could be phrased something similar to….”Mr. X, were you aware that the loaded weight of your trailer was over 5,500 pounds, that the manufacturer’s minimum recommended hitch weight is between 620 and 750 lbs, and yet you had only a 550 pound rated hitch on your Tow Vehicle”?

What argument do you have at that point for defending a hitch with a 550 lb rating?

Anyone who can comprehend “Ned and the First Reader” should be able to infer that that the ratings are “up to, and not to exceed”...any tongue load above 550 lbs requires a higher rated equalizing bar.

Inland RV wrote:

Research data, from over 20 years, bears out that you were "grossly" over hitched, and really, you were a predictable accident, looking for a place to happen.


As far as the comment that the vehicle was “grossly over hitched”, I submit that there is no detriment at all to being “over hitched”, as long as the weight distributing bars are set properly when hitched to an appropriately rated tow vehicle. Reese currently incorporates links that are about 1” in length, allowing for accurate settings of lift arms rated to1200 lbs . If you were towing a popup or similar lightweight trailer with a tongue weight of less than 300 lbs, then MAYBE too much load could be transferred to the frame of the trailer, but trailer frame design is not in question here.

As far as an accident looking for a place to happen, from the information presented here about your hookup, again assuming that the Reese was properly set up, a working brake controller, properly serviced and adjusted brakes, and other tow and trailer equipment in working order, I offer, in my opinion, that you were about as conscientious and conservative in your choice of TV/Trailer as could be expected.

Personally, I fail to understand how any accident could be attributed to being “grossly over hitched”, maybe Inland RV could provide specific occurrences. Weight distribution happens when the end of the lift arms (however they are configured) are stressed (sprung within their elastic limit) in order to transfer weight. It should not matter wether or not it is done by a 2" lift on a 600 lb arm or a 1" lift on a 1200 lb arm (as long as the stresses [loads] DO NOT EXCEED THE MANUFACTURERS RATING). Sway control requirements aside, ANY lift of an arm (even a 1200 lb arm on a "light" trailer will require a couple of inches of lift) should be enough to gaurentee a proper range of "spring action" over most any terrain at appropriate speed.

Andy’s comment is something akin to “the accident occurred because the hitch had too much of a safety factor”.

Perhaps Inland RV will share the data he refers to with the Forum. I, for one, am most interested in the breakdown of RV accidents attributable to inadequate Tow Vehicles, aged or impaired drivers, inadequate or absent safety equipment, deficient brake systems, or other category that data from State, Federal, Insurance Company Investigations, may be available and shared with the public. If the accident mentioned is attributed to sway control (or lack of it), there has been precious little discussed ANYWHERE about the requirements or parameters of sway control - how can you measure the value of sway control without measuring the number of accident incidents in which lack of sway control has been a factor? Now, I know first hand how important sway control is, I am not minimizing its importance, simply pointing out that there are no industry (or minimum) standards to compare one hitch against another.

But “Grossly Overhitched”? – In my opinion, I think not - unless you have been doing business with Can-Am and removed your rear wheels just to see how it would handle as a 50’ integral unit.

Believe it or not, Reese actually has a warning NOT to do this on their website:

http://www.reeseprod.com

Talk about CYA to protect from litigation by stupid people.

Actually, the initial install and setup PDF’s should be required reading for anyone towing anything more than a pop-up, even if you don’t have a Reese hitch.

In synopsis, in analyzing the safety of any our personal TV/Trailer/Hitch hookups;

Take time to familiarize yourself with your present setup, and be cognizant of any “new” equipment on the market which may help you enjoy safer and more enjoyable trips.

Be very, very careful when taking advice from anyone within this Forum, on a sales floor, or in anecdotal conversation…..the final responsibility for a safe tow rests solely on you, the driver.

Use your head, if you don’t have any common sense, borrow some, but by all means adequately assess all opinions of what constitutes a “safe tow”.




Inland RV wrote:

The fortunate thing however, is that your OK.


Andy is 100% correct on this point. It indeed is providential that you walked away from this incident, and, perhaps just as importantly, have chosen to share this experience with us. We should not sit in judgment in these matters, it is important to learn from the (possible) mistakes of others to insure that we (individually and as a group) do not duplicate the misfortunes of others. Honest and objective debriefings by those involved in accidents or near misses are the only means we have of learning those horrific and expensive lessons other than experiencing them ourselves.

If there were other parameters or mitigating circumstances contributing to the accident, I beg of you to include them in this thread for our communal edification.

I thank you for giving the Forum the opportunity to learn from your misfortune.

[Chuck]

Why, (very briefly), unless the bars are bending a minimum of and inch or so, (more is superior) the hitch will not provide much sway control.

The harder it becomes for the bars to rise on the saddles, the better the sway control.

so its not really a matter of how much weight is or is not being transferred, but how much of a squeeze is being put on the spring bars...or more accurately, how much tension is on the bars, and their response to it. that actually makes me feel good, because when my rig is all set up, the spring bars do have a bit of a bow to them. I was worried that this might be a bad thing, but perhaps not. (I have never felt so much as an incling of sway from back there. all I feel is "weight" on the steep hills! ).

what I don't understand is how the tow vehicle's weight rating enters in to this. The force on the spring bars comes from the trailer's tounge weight. It would seem to me that the amount of "bow" in the spring bars wouldn't change based on the suspension of the tow vehicle.

[Inland RV Center, In]

Rigging questions.

I do not, at this time, have the time to go into great detail to document what I previously posted.

Unfortunately, some people don't believe in statistics, as you can gaurantee yourself will happen here.

However, the levelness of the tow vehicle has "NOTHING" in itself to do with proper rigging.

The follow statement has been made thousands of time, and "no one" has yet to prove it wrong. Anyone can dispute anything, but research, especially the kind that can easily be duplicated, leaves the disputer in wonderment.

The rule is simple. RThe tow vehicle and trailer must be level within themselves, and, at the same time the torsion bars "must" bend a minimum of 1 inch (Reese).

If they do not adequately bend, then obviously, they do not transfer any weight.

87MH. If the rating of the bars don't matter, then lets use railroad track.
I hate to disagree with you, but the research bears you out in the wrong.

Additionally, the front of Airstream and Argosy trailers love a "soft" ride. When the front end of the trailer is punished by havivg a super stiff hitch and/or rear end suspension, then in short order, the rivets in the front plate start to shear off. Ask anyone who has experienced the loss of those rivets, what kind of tow vehicle you have as well as the rating of the hitcxh, and the answer will be, "big hitch, big truck,"

Speaks for itself.

This is not theory guys, this was well documented research.

For those that still differ, I suggest that you first read the December issue of Airstream Life.

I do not (at this time) have the time to go into this with infinite detail, or to answer the questions that someone may feel reasonable. And I especially will noit get into a discussion with an Attorney about this matter, as they always seem to have a way to bend or alter proven facts.

If your a doubter, I have but one suggestion.

Make sure you have plenty of collision and liability insurance, before you make your next trip.

Andy

[TomW]

Originally Posted by Inland RV

...I do not (at this time) have the time to go into this with infinite detail, or to answer the questions that someone may feel reasonable...

Ya know, what has been missing from this thread (at least to me) is definition of the various terms being used. I understand what a weight distributing hitch is supposed to do, and I have my own “dictionary” of what the parts are called.

Allow me to share it with you, and please correct what I have wrong:

Hitch: More completely called a “Receiver Hitch”. They are divided into Classes according to their weight carrying capability. I believe Types I - V are associated with light trucks.
To me, the hitch should be sized to the maximum tow rating of the vehicle no matter what one is towing. Is this one of the bones of contention?

Drawbar. The bar with ball inserted into the hitch & secured with a pin. The drawbar is usually sold separate of the hitch, and is usually matched to the weight distribution hardware. Many different drawbars will fit a given receiver hitch. Additionally, many different WD bars will fit the same drawbar.

Weight Distributing (WD) bars. This thread occaisionally calls them “spring bars” which they are, but it is a new term to me. These bars span between the drawbar & trailer, and serve to redistribute the tongue weight.

I know that WD bars are sold with different characteristics. I’m thinking this is the heart of Inland’s “too much hitch” presentation.

So what do I have wrong?

Tom

[59toaster]

Well I see Dennis post as more what a Lawyer will pull in court but I see Andy’s point of being over hitched.

What was neglected to be pointed out was the following:

WEIGHT TRANSFER UNDER BRAKING: Here me out and I think you will understand why it's critical to get the deflection that Andy speaks of for the Dual Cam to be effective.

Under hard braking the tow vehicle will nose dive....we know this do we not? It's a given. Its a fact that a four wheel vehcile wil have weight transfer to the front that will cause the attitude of the vehicle to change dramaticly from it's normal static ride hight.

Think about what is happening at the hitch and bars when the vehicle nose dives.

The hitch is raising and that is lowering the tension on the bars. Many of use will actually run the jack up to make it easier to hook the chains up thusly proving when the tail of the tow vehile raises there is a loss of tension. The more distance from the rear axle of the tow vehcile to the ball the more this movement will increase. The longer the wheel base the less this will happen. The vehcile in question was of a shorter wheel base and it was also a high center of gravity vahile so this transfer could be quite dramatic.

Since the dual cam depends on that tension to function the load transfer significantly reduced the effectiveness of the Dual cam to fight sway. Once the trailer overcame the Cams it would be able to push the rear of the tow vehicle side ways causing a loss of control.

[Chuck]

I have to agree, I do think there is some intermixing of terms, here. One thing I can't believe is a true statement though, is this:

"If they do not adequately bend, then obviously, they do not transfer any weight."

a):, its not obvious. and b): I could use a piece of spaghetti in place of the wd bar, and it would bend, but no weight would be transferred. or I could use a piece of railroad track, and if I pulled up hard enough on it, it would flip the tow vehicle right over, without bending at all. the weight would be transferred. but the rail wouldn't bend, because the weight of the tow vehicle and trailer combined wouldn't exceed the tensile strength of the bar.

you might be able to convince me that the cams need to be oriented in the saddles a certain way, and that there needs to be a minimum amount of friction in order for the sway control to work properly. but a lever doesn't have to be bent in order to produce leverage. the force is there, whether we can see it or not.

[Silvertwinkie]

Ok, ok..uncle.

So I thought I had this all figured out and now this new info. So on my old Impala, when I towed the Bambi and the Airstream dealer set me up with 1000lb bars I was in overkill mode and no weight was being xfered? How could this be if the bars brought the rear of the car level to the trailer?

Now I have a 3/4 Suburban that I have yet to hitch up. I am thinking that I will not need 5 links as I did when towing the Safari with the Impala (I used 2 or 3 links towing the Bambi with the Impala). So if the truck drops a few inches, I hook up my 1000lb bars and it raises the rear of the Suburban making it and the Safari near or at level, again, how am I not xfering the weights if the vehicles are responding to the weight bars? My 1000lb bars rarely bend all that much.

Now the Safari has a published hitch weight of 750lbs. Which if I load the front end of the coach up, could easily reach say 800lbs. So am I still over hitched with 1000lb bars to the point of poping rivets or causing hardship to the coach?

Not trying to start an arguement or point fingers at who is right and who is wrong....I'm just lookin' for answers so that I don't screw up as I have seen first hand what happens to folks that play the odds. I don't want to be one of those folks.

For the record, brakes, dual cam and controller are all in 105% condition.

[TomW]

Originally Posted by 59toaster

Well I see Dennis post as more what a Lawyer will pull in court but I see Andy’s point of being over hitched...

Okay, since I am slow on the uptake, what is "overhitched"? Which part is too much for what is being towed? I have re-read this thread, and still have not figured out what everyone is calling "overhitched"


Tom

[overlander64]

The Reese technician who taught me to setup my hitch (1998) basically instructed me according to what Andy posted earlier. As such, I have four sets of weight distributing bars for my Reese Strait-Line Hitch (the Strait-Line Hitch includes the Dual Cam Sway Control System) to match my two coaches to my two primary tow vehicles - - a VERY softly sprung Cadillac and a much more stiffly sprung K2500 Suburban.

My 6.0 Metre Minuet has 3,100 pounds gross trailer weight/550 pounds gross hitch weight, and the 26' Overlander has 6,100 pounds gross trailer weight/750 pounds gross hitch weight. When towing with my car, I use 600 pound bars with the Minuet and 800 pound bars with the Overlander; with the Suburban, I use 500 pound bars with the Minuet (these were from the old light weight system sold by Reese in the late 1970s) and 700 pound bars with the Overlander (these bars were evidently from a source other than Reese but fit the Reese hitch head). The hitch heads and draw bars are rated for 1,000 pounds hitch weight (with weight distribution) and up to 10,000 pounds gross trailer weight (with weight distribution).

When I first purchased my Overlander in 1995, the dealer who setup my hitch (not an Airstream dealer, but a general hitch specialist) installed the Reese hitch with 1,000 pound weight distribution bars (at the time I was towing with a '95 K1500 Z-71 Chevrolet Club Cab pickup with VERY stiff springs (the rear suspension deflected less than an inch with the load of the Overlander). I had many "white-knuckle" experiences with that combination. When I approached a Reese Technician at a different facility than the one who installed my hitch, the problem was immediately diagnosed as weight distribution bars that were much too heavy and is when the 700 pound bars were fitted for the Overlander - - I have towed with the lighter bars since 1998 with no reappearance of the "white-knuckle" experiences with the heavier 1,000 pound weight distribution bars.

It has been nearly ten years since I have towed with anything other than the Reese Strait-Line hitch with Dual Cam Sway Control, and after switching to weight distribution bars better matched to my tow vehicle trailer combination (1998) I have not had any "white-knuckle" experineces. I had always thought that the matching of the weight distribution bars to the gross hitch weight/stiffness of tow vehicle springing was more to insure proper functioning of the Dual Cam System, but now it appears that it applies in general as well.

Kevin

[Inland RV Center, In]

Tom.

You are correct. It is the weight rating of the torsions bars, also known as bars, spring bars, weight distributing bars, load equalizing bars, or arms instead of bars, and who knows what else.

The other and very important item, is the amount of spring, or the spring rate, or the beef up equipemt installed on the rear of the tow vehicle.

We all know that you can keep any tow vehicle level, without any form of load eqaulizing hitch, and simply tow an Airstream with a ball. Laugh as you may, there are some that do it.

In order to do that, the rear suspension of the tow vehicle, must be beefed up. When that is done, as an example, we can keep the trailer and tow vehicle level, with respect to itself.

However, rarely, does anyone do an investigation, let alone research, as I have when I was with Caravanner Insurance, relative to load equalizing hitch uses.

When both vehicles are level, using a beef up method, they look great. Tow them past 35 to 40 mph, and you will learn a lesson, quickly. When that setup is made, and because of the increase in the fulcrum, check the 3 weights on a truck scale. What you will find, is that the front end of the tow vehicle weighs maybe half of what the rear axle weighs.

Simply put, the front end will handle the same as if you were on ice. Namely, traction, where did you go??????

Again guys, there are many facets to this that will "all" be listed in that article. In the meantime, please lets be patient.

I have been here for 38 years to help, not to hinder. It has always been my desire to improve our industry with knowledge and facts, that promote your safety. I know how to do it, but unfortunately, all too many don't. It is in that vein, that I strive to promote safety, through knowledge and research information passed on to our fellow RV"ers.

There will always be those that object, but I personally have yet to meet or communicate with anyone, that has an extensive background, specifically on this subject, or hands on involvement with the research program itself.

I truly believe, if we had more listeners to the real facts instead of objectors, that most of us would be far better off.

Unfortunately, all too often, we find misguided advice handed out, even though is was well meant.

The research project included various lengths of Airstreams, real as well as doctored tongue weights, different tow vehicles, along with modifying some of the tow vehicles by adding overload springs, air shocks, air bags, Monroe Load Levelers, as well as altering some of the "heavy duty" suspensions sytems, down to a normal system.

Oh, and while I am at it, towing a loaded 31 foot Airstream at 115 mph, with a tow vehicle that was equipped with a calibrated speedometer, an air speed indicator, and a camera to film it all, was part of the project. I was the driver!!

Having been a major part of that research, at least in my opinion, has given me considerable towing knowledge, that would be virtually impossible for any individual to duplicate.

It is near time to share this with one and all. But I promise, I will write what I know, but I "will not" get into any off the wall discussions with anyone, that wants to object, at least until "they" personally did the same research.

I will be happy to answer questions on a time available basis, but I will not get into a contest.

I have made a very good living, by rebuilding wrecked Airstreams, that were damaged by people who thought they knew, but learned, they really didn't, as well as modifying and remanufacturing them.

In other words, do as you wish, I can rebuild the damaged coach, and have for 38 years. But I would much rather reduce that work load, by trying to help people "before" they have a problem.

Proper rigging is like PM. If you ignore it, sooner or later it will bite you.

But, many owners don't believe in PM, so why in the world would you expect them to be safety concious?

Beats me!!

Again, please be patient, and look forward to those articles.

Andy

[Silvertwinkie]

Ok, so if I am hearing you all right, our Safari is about 750lbs hitch weight and towing with the Suburban or the Impala, I should be using less than 1000lb bars?

[59toaster]

Originally Posted by tcwilliams

Okay, since I am slow on the uptake, what is "overhitched"? Which part is too much for what is being towed? I have re-read this thread, and still have not figured out what everyone is calling "overhitched"


Tom

Now right off the bat. My observation is on a Dual cam set up and it's my understanding that is what was in use at the time of this accident. It is critical to it's performance that the cams stay in firm contact with the saddle.

Understanding that if you tilt the trunion back that this will cause the bars tips of the bars to be lowest as they come together in a straight line behind the tow rig. Under upward pull at the ends of the bars the bars will try to swing to the sides. This tendency helps with sway. To bars on opposite sides of the hitch under tension will always try to move away from each other. They act as a counter balance as a result if the trailer gets out of line with the tow vehicle. The one to the inside will loose tension. The on the outside will gain it as to gets closer to in line with the hitch.
Remember that as you read.


You have to think about what is happening at the end of the bars as the combination is articulating.

I 3/4 ton truck is going to need less tension on the bars to get the truck back level.

A half ton truck is going to need more because the rear will drop more with the tongue weight


We agree on this?

So if we have the same set of bars the bars on the 1/2 ton truck is going to be flexed more because we have to move more weight to the front axle to get the rear of the truck up right?

If the hitch rises there will be more travel where the bars are applying a downward force on the chains on the 1/2 ton because they have more tension to raise the rear of the truck back up. Agree?

Now think about the truck going over a bump that raises the back wheels of the tow vehicle. IF THE BARS HAVE TO BEND MORE THEN THEY WILL STAY IN TENSION LONGER AS THE REAR OF THE VEHICLE RAISES.....agree?

Think about it. If the bar has to deflect 1.5 inches on the half ton to get it level and the 3/4 ton because of its firm springs only needs 3/4 of an inch the distance the rear of the vehicle has to be raise before the bars loose tension will be less. Agree?


On a 3/4 ton the vehicle is able to handle a higher load so there is less tension needed to get the tow vehicle level. My 3/4 ton burb only drops 1 inch at the back bumper with 700lb of tongue. The front comes up 3/4. It does not take a whole lot of tension on a 1,000lb bar to get it back level.

So if my bars are of a higher tension then they are flexing less. The rear of the vehicle has to come up less distance before the bars loose tension because they have so little deflection in the fist place. It’s OVER HITCHED. It needs lighter bars to get the deflection back to keep the Cams of the Dual cam effective.

Back to my point about trunion angle. The more the vehicle is turned the less tension on that inside (of the turn) bar so it is not exerting as much tendency to try to re center the hitch. The Dual cam is also becomeing less efective on the inside bar because it has less tension.


There is a WHOLE lot going on at the hitch that is not obvious. You have to take it all in. Level vehicle is only part of it. Start changing the attitude of the tow vehicle in relation to the coach has to be considered as well. Andy's point of over hitch sort of sounds misleading but if you really start thinking about it makes perfect sense. It's OVER HITCHED. The equipemtn is larger then needed and it lessens the effectivness of the Dual cam.

Thanks Andy.

Got me thinking on that one. I did learn a lot about the tow characteristics between different vehicles. My rough riding 3/4 ton burb just may get some half ton springs and make life a littler better on the kidneys. At the very least a set of 550lb bars is in my future.

[Sav'h Steve]

Originally Posted by 59toaster

Now think about the truck going over a bump that raises the back wheels of the tow vehicle. IF THE BARS HAVE TO BEND MORE THEN THEY WILL STAY IN TENSION LONGER AS THE REAR OF THE VEHICLE RAISES.....agree?

Think about it. If the bar has to deflect 1.5 inches on the half ton to get it level and the 3/4 ton because of its firm springs only needs 3/4 of an inch the distance the rear of the vehicle has to be raise before the bars loose tension will be less. Agree?

On 59 toaster's first statement about braking, I got to thinking about the loss of tension and started to comment. But his second statement really echoed my thoughts.

It DOES seem counter-intuitive, that one would use LESS strong (lower rating) bars on a 3/4 ton truck with heavy springs. But we all do learn to use the power jack to 'make it easier' to put on the springs. Isn't this exactly what happens when we brake?

So..... Toaster! Here is a toast to you (and others) who helped to explain what isn't so obvious!!

I too have thought of 1/2 ton springs for my 3/4 Burb. And I'm using 750lb bars (I think). I do have a set of 1000lb that never get used.

I think that too few people really understand this.....

Steve in Sav'h

[59toaster]

No the toast goes to Andy. I just tried to explain it differently.

Andy is explaining it in relation to what is happening at the front of the vehcile becuase it's loosing the weight transfer from the hitch. When that angle changes the bars are not shifting the weight forward. I had a little trouble comprehending that till I started to think what was happening at the hitch.

It was easier for me to understand once I grasped the loss of tension on the bars if the attitude of the tow vehcile to the trailer changed. That's the point of Andy saying those bars need to defect a minimum of an inch. Everybody is so critical on the tounge weight but thats really secondary in the Dual cam. Yes your goal is to level but It's the need for those cams to have downward force from the Bars at all times to be effective. That deflection guarantees it.

Most of us have seen that picture Can Am has with the three leged Toranado where they took a wheel off the rear and let the hitch take up the slack. That's an example of transfering the weight to the front axle in the way Andy was explaining it.