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Old 09-22-2014, 09:28 AM   #281
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What does a snowplow weigh?
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Old 09-22-2014, 09:43 AM   #282
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Quote:
Originally Posted by Flyingsilver View Post
Ron, thank you for the note, but you got me a bit confused now with the weight transfers. Here are my truck numbers, front, 3700, back, 3900, my max payload is 1432lbs, max towing is 7900 and my Gcvw is 13500. Since my tongue weight as is was 740, don't I need to transfer another 140lbs or so to the front axle?---
The numbers indicate your tongue weight was about 1010# with 250# of that being transferred to the TT's axles.
The remaining load of 1010-250 = 760# was added to the TV's axles.
The amount added to the rear axle was 3780-3140 = 640#.
The amount added to the front axle was 3540-3420 = 120#.

The front axle load of 3540# is 160# below the front GAWR.
The rear axle load of 3780# is 120# below the rear GAWR.

If you transfer another 140# to the front axle, its load would increase to 3680# -- 20# below the front GAWR.
Transferring another 140# to the front would cause about 200# to be removed from the rear axle (and 60# would be added to the TT's axles).
The rear axle load would be decreased to 3580# -- 320# below its GAWR.

IMO, a better definition of "balanced" would be to have both axles approximately the same amount below their respective GAWRs.
You are at that point if you don't increase the load transfer.

I recommend that you not transfer any more load to the front axle.
If you keep the WDH adjusted as it was when you obtained the 3540/3780 axle loads, your FALR would be about 130% versus the maximum of 100% now being specified by WDH manufacturers.
Too much FALR increases the chance for oversteer.
However, in your case, if you decrease the load transfer to get a lower FALR, you will get closer to exceeding the rear GAWR.
You have to decide which is the lesser evil.

BTW, if you try to get 1/3 of the tongue weight added to both the front and rear axles,
you would end up with 3760# on the front -- 60# over front GAWR and
you would end up with 3480# on the rear -- 420# under rear GAWR.
IMO, that's not a good objective.

Ron
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Old 09-22-2014, 10:04 AM   #283
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Quote:
Originally Posted by SteveSueMac View Post
---I think Ron was saying you don't want more than 100% FALR.
In general -- you should not exceed 100% Front Axle Load Restoration. Some TV manufacturers now say 50%.

However, the rear axle load also must be considered.
In Flyingsilver's case, his TV had 300# of cargo in the box plus a 300# camper shell.
If he tries to get the FALR down to 100%, he runs the risk of exceeding the rear GAWR.

As stated in my previous post --
If the FALR is too high, you have an increased risk for oversteer.
And, in some cases, if the FALR is too low you have an increased risk of exceeding rear GAWR.
The answer to the dilema is a TT with lower tongue weight or a TV with greater carrying capacity and/or less cargo weight.

Ron
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Old 09-25-2014, 09:41 AM   #284
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Quote:
Originally Posted by Ron Gratz View Post
The numbers indicate your tongue weight was about 1010# with 250# of that being transferred to the TT's axles.
The remaining load of 1010-250 = 760# was added to the TV's axles.
The amount added to the rear axle was 3780-3140 = 640#.
The amount added to the front axle was 3540-3420 = 120#.

The front axle load of 3540# is 160# below the front GAWR.
The rear axle load of 3780# is 120# below the rear GAWR.

If you transfer another 140# to the front axle, its load would increase to 3680# -- 20# below the front GAWR.
Transferring another 140# to the front would cause about 200# to be removed from the rear axle (and 60# would be added to the TT's axles).
The rear axle load would be decreased to 3580# -- 320# below its GAWR.

IMO, a better definition of "balanced" would be to have both axles approximately the same amount below their respective GAWRs.
You are at that point if you don't increase the load transfer.

I recommend that you not transfer any more load to the front axle.
If you keep the WDH adjusted as it was when you obtained the 3540/3780 axle loads, your FALR would be about 130% versus the maximum of 100% now being specified by WDH manufacturers.
Too much FALR increases the chance for oversteer.
However, in your case, if you decrease the load transfer to get a lower FALR, you will get closer to exceeding the rear GAWR.
You have to decide which is the lesser evil.

BTW, if you try to get 1/3 of the tongue weight added to both the front and rear axles,
you would end up with 3760# on the front -- 60# over front GAWR and
you would end up with 3480# on the rear -- 420# under rear GAWR.
IMO, that's not a good objective.

Ron
Hey Ron,

Thank you for your notes. Here are some numbers for a new try at the cat scales. I weighed the tv and tt again with the same weights we had from our previous stop at the scale. Same fuel in the tank, same water in the fresh tank, bags etc, however i re arranged some of the weight in the cargo area, got a couple of suitcases and tools moved behind the rear axle. steer axle, 3480, drive axle, 3660, trailer axle, 5680, drove on I10 around 100 miles for testing purposes the truck and tt combination in terms of sway, handling, steering, was just fine. However from my previous post to Andy I have my chains up to the fourth link. You did mention in one your replies to leave the truck as is from my last stop at the scale and no to transfer any more weight to the front axle in order to keep theWD the same. So here we are with some different results by just redistributing the cargo weight. In terms of having the chains and tension to them by having them at the 4th link does it makes sense to you? At last, I don't think that we will try to find the perfect answer to the dilema as you quoted by trading all these new equipment to a Peterbilt and a Bambi, sort of speak.
However I will be more interested in learning from you and your past or present experience, what kind of AS are you towing, truck , hitch, weights., how do you personally confront all these dilemas a about manufacturers ratings, and so on. Cheers,
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Old 09-25-2014, 09:47 PM   #285
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Quote:
Originally Posted by Flyingsilver View Post
---I weighed the tv and tt again with the same weights we had from our previous stop at the scale. Same fuel in the tank, same water in the fresh tank, bags etc, however i re arranged some of the weight in the cargo area, got a couple of suitcases and tools moved behind the rear axle. steer axle, 3480, drive axle, 3660, trailer axle, 5680,---

---So here we are with some different results by just redistributing the cargo weight. In terms of having the chains and tension to them by having them at the 4th link does it makes sense to you?---
No, it doesn't make sense to me.

If you didn't add or remove load from either the TV or TT, but only redistributed the load, the GCW should have remained the same (within scale accuracy) as for the last weighing.
However, the previous GCW was 3540+3780+5600 = 12920#.
Your latest measured GCW was 3480+3600+5680 = 12760#.
The TV's GVW decreased from 7320# to 7080# -- a loss of 240#.

If you moved cargo from ahead of the rear axle to behind the rear axle, I would expect to see and increase in rear axle load.
However, your data show a load decrease of 180#.
There must have been more than just a redistribution of load.

Quote:
However I will be more interested in learning from you and your past or present experience, what kind of AS are you towing, truck , hitch, weights., how do you personally confront all these dilemas a about manufacturers ratings, and so on. Cheers,
When we became fulltime RVers nine years ago, we traded towing a 27' Award TT with an Expedition for towing a 16' Ford Explorer with a 41' motorhome.
During three years of towing a 5000# TT with an Explorer carrying a 140# dog and a fair amount of other cargo in the TV, I didn't know enough about ratings to realize I might be exceeding some. Switching to an Expedition resolved any dilemmas.

Now, towing is simpler when the tow vehicle weighs seven times as much as the towed vehicle. And, there's no WDH to adjust.
The tow vehicle is 5000# below its GVWR and the towed vehicle is 5000# below the towing capacity.
There are no dilemmas -- other than not being able to back up or turn around in a reasonable radius.

Ron
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Old 09-26-2014, 11:17 PM   #286
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Originally Posted by Inland RV Center, In View Post
Your almost there.

Ideally, 2/3 rd's of the 960 should go to the tow vehicle. Your weights show 760 pounds instead of 620 pounds. That means the bars are not doing the best job that they can.

Tilt the ball mount down ward some more, so that 5 links are stressed much more than originally, even more than with the 4 links.

The bars may bend 2 inches, or more, which would improve the handling even moreso.

With the present setup, how much are the bars bending?

Andy
Greetings, Andy or anyone else, dou you know a good shop or an Airstream dealer with a good hitch installer that can help me with my set up. I am not experienced enough to fix the issues we have with our current set up. Either in Tucson or Vegas. I will really appreciate it, since we wil be on the road next month for a whole year we need to get this as to match as perfect is possible. Thank you
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Old 09-27-2014, 01:19 PM   #287
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" . . BTW, if you try to get 1/3 of the tongue weight added to both the front and rear axles, you would end up with 3760# on the front -- 60# over front GAWR and you would end up with 3480# on the rear -- 420# under rear GAWR. IMO, that's not a good objective."

" . . If you have 900 pounds tongue weight, 300 should go back to the trailer axle/axles and 600 should go to the tow vehicle, with 1/4 of that weight on each wheel of the tow vehicle."

(Andy, what was the "rule"? Additional weight more to the Drive Axle where otherwise the split was approximately 1/3 - 1/3 - 1/3?)

SAE has left enough holes in J2807 to beg quite a few questions, on the one hand, and data from 40 years ago (which we all used until a few years back) may or may not have been superceded by the different TV's of today. The trailer, any type, is as much in question as the TV.

FWIW I wouldn't be concerned by 60# over on the Steer Axle. But there might be room to reduce that slightly and let it settle on the Drive Axle. It certainly is where I'd start. Vehicle manufacturer guidelines are the starting point, but only that.

The problem is in testing for the dynamics while on the road. Which is recognized by both statements quoted above. As SAE is a group of engineers captured by industry -- where profit matters more highly -- pushing folks towards pickups appears to be the goal over establishing a broader context of suitability in recommendations of a TV. Aero design is ignored entirely in favor of weight only. So, then, perhaps, for rollover-prone pickup trucks where trailer yaw is of more vital concern . . . .

I would, (will, in my case, with heavier & longer TT & TV) go back and forth. Experimentation begins with scale derived data, IMO, it doesn't stop there.

FlyingSilver if you can reach approximately FALR and the TT is level with WD appled, you are good enough for a beginning. A weight scale is central to this. Scale tickets are your friend. A BIG stack is just what most of us acquire over time as there is the initial set of adjustments, and then the limited range of adjustments afterwards.

TV tire pressure (as TT tire pressures are always to sidewall maximum) and tweaks of the WD per latest loading is what this is about. RobertCross makes the point of checking the rig on the scale annually afterwards. Find the range first, and the rest is simple enough to experiment with as you go along.

Good luck

Ross

.

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Old 09-28-2014, 10:50 AM   #288
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I know this is going to sound silly, but what kind of scale and where do you find one? Are we talking truck stop type scales along the highway?!
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Old 09-28-2014, 10:52 AM   #289
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Yes.
The Cat scales are not for weighing house cats or big cats-
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Old 09-28-2014, 12:15 PM   #290
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Quote:
Originally Posted by Ron Gratz View Post
Andy, can you provide the details on HOW "physics" was used to prove that TV/TT combinations should carry 1/3 of the tongue weight on the TV's front axle, 1/3 on the rear axle, and 1/3 on the TT's axles?

Since the TV and WDH manufacturers now are giving WDH-adjustment specifications which differ from that finding, perhaps the researchers now have different data and/or different analytical methods on which to base their conclusions.

Ron
Has a car manufacture ever tested an Airstream?

Not to my knowledge.

And, if that is the real case, then how can they, or anyone else, every make up a formula or this is what you should do chart. Then how can they say "anything" about towing an Airstream?

There are many people that both agree as well as disagree with your thoughts. That certainly is their privlege, but their thoughts are simply an opinion, instead of facts.

Opinions, most always are to share, since it can bring up new questions.

But facts, can easily be repeated, again and again.

Just like Physics. It doesn't change with time, but opinions do.

Many rules of towing, do not apply to an Airstream.

Many Airstream towing rules, don't apply to brand "X".

Why??

Physics.

When you say they "MIGHT" have different data, your absolutely correct.

The data they have is ZERO., when it comes to towing an Airstream.

Airstream is a different breed of travel trailers. As such, different things must apply.

Wally, has worn out his clothes, in his casket, by turning over and over, of some of the opinions that are generated because of what he created. On the other hand, I am more than positive that Wally has bumped his head many many times, when trying to get up and saluting those responsible for todays fanastic Airstreams.

The factory as well as many dealers, don't sell a person intersted in an Airstream. That potential customer was sold before they ever set foot in one.

Just think how you perhaps decided to get one, or even more in time.

Yeah Airstream.

They have guts and courage to be different than others, and quite sucessful in doing so.

To me, they are the far out leader, in doing what many people say can't be done.

Their responce has always been, watch us get it done.

That's perhaps the reason I continue to work with them, as well as a few others, for almost 50 years.

Andy
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Old 09-28-2014, 09:55 PM   #291
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Many Airstream towing rules, don't apply to brand "X".

Why??

Physics.
Andy, can you provide the details on HOW "physics" was used to prove your Airstream towing rule which states that TV/Airstream combinations should carry 1/3 of the tongue weight on the TV's front axle, 1/3 on the rear axle, and 1/3 on the TT's axles?

Ron
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Old 09-28-2014, 10:27 PM   #292
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Quote:
Originally Posted by Ron Gratz View Post
Andy, can you provide the details on HOW "physics" was used to prove your Airstream towing rule which states that TV/Airstream combinations should carry 1/3 of the tongue weight on the TV's front axle, 1/3 on the rear axle, and 1/3 on the TT's axles?

Ron
This position can not be defended unless the distance between the rear axle of the TV and the center of the trailer axles is exactly the same as the distance between the rear axle of the tv and the front axle of the tv.

The law of physics in question hear is the law of leverage.

The only thing that is unique to an Airstream, with respect to towing, is that it has to ride parallel to the ground if there is more than one axle. This s a function of the type of suspension.
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Old 09-29-2014, 07:22 AM   #293
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Quote:
Originally Posted by Ron Gratz View Post
Andy, can you provide the details on HOW "physics" was used to prove your Airstream towing rule which states that TV/Airstream combinations should carry 1/3 of the tongue weight on the TV's front axle, 1/3 on the rear axle, and 1/3 on the TT's axles?

Ron
Ron.

Please do some of the testing yourself.

I don't think I need to explain, or for that matter, have to defend Physics.

Not everyone understands the laws of Physics.

Andy
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Old 09-29-2014, 06:59 PM   #294
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I finally got my Reese hitch installed this weekend. Sitting on a windy hilltop while boondocking. With a cordless drill.

On the cast top piece that holds the spring arms, the same piece that the ball attaches to, there is a cast arm sticking out to the right of the ball. It has a vertical hole in it. it looks like it could be some kind of linkage, but I found no mention of it in the instructions. Anyone know what that little arm does?
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