Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-04-2009, 06:38 AM   #71
Just an old timer...
 
85MH325's Avatar

 
Tipton , Iowa
Join Date: Mar 2003
Posts: 4,031
Images: 37
Quote:
Originally Posted by azflycaster View Post
The hitch on the basecamp is a single tube. It would have to be modified to use anything but the single arm wd setup.
Thanks Richard! I had forgotten that. I haven't looked at one since they were first introduced.

That single-tube tongue also presents a huge problem. And re-visiting the design of the Reese single-bar WDH, I'm not even sure that's an option for you as that snap-up bracket is designed to fit across the top of an A-frame tongue...

You may not have any WDH options for your Basecamp without some significant modifications.

Roger
__________________

__________________
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"
85MH325 is offline   Reply With Quote
Old 06-04-2009, 08:02 AM   #72
Rivet Master
 
JimGolden's Avatar
 
Vintage Kin Owner
1977 31' Excella 500
Berkeley Springs , West Virginia
Join Date: Sep 2005
Posts: 1,619
Images: 7
I myself have wondered about utility trailers. I have a 16' flat bed (22' long actually) that I haul tractors and stuff on with no weight distribution and it's fine and doesn't sway at all. But, I think the main reason is that the axles are set further aft on it than on the travel trailer, so that it's naturally tongue heavy. Forward CG = naturally stable.

When I load either of my trailers, I always try to keep the weight forward of center. Doing that, I've never had one get unruly on me.

The rule of 10-15% of the weight of the trailer being tongue weight is really an approximation. What you actually want is the CG of the trailer to be about 15% forward of the center line of the axles. You could do the math and see what your tongue weight should really be easily enough. I will admit that I have not done this yet myself. But I'm sure I'm close just because of the good handling of my rig as I havei t set up.

I did a very long detailed thread on here a couple years ago on how to set up an Equal-I-Zer. Anybody considering the Eq might want to read it. I've been very happy with mine. It doesn't have the "magic" geometry of the Hensley or Pro-pride (they do like sports car A-arms where you have them non parallel and project a roll center....the hitches project that center up ahead of the "pumpkin" so that it handles like a fifth wheel....very good design). But for a friction hitch, I like it very much. As well, I try to balance the trailer properly when I load it so I'm not trying to overcome a terrible handling setup anyway.

I'll check out that newer SAE paper. I wasn't aware of it. Sounds like great minds think alike on their test apparatus

see you all on the road,
__________________

__________________
- Jim
JimGolden is offline   Reply With Quote
Old 06-04-2009, 08:27 AM   #73
Rivet Master
 
SteveH's Avatar
 
2005 39' Land Yacht 390 XL 396
Common Sense , Texas
Join Date: Sep 2007
Posts: 5,311
In my opinion derived from towing travel trailers, boat trailers, and utility trailers since '65, the problem we call sway (really a sort of fishtail oscillation is a more accurate discription in my mind) is almost non existant with trailers that have little to no wind resistance....i.e. utility trailers, and such.

Even my Airstream when there is little to no wind, or not being passed by large truck, exibits NO tendency to sway. I have experienced it mostly with travel trailers, and the bigger and more square, the bigger the tendency. This, all is assuming the trailer is designed properly, hitched properly, and all the tires are inflated properly.

So, the major problem as I see it with sway and travel trailers is wind, and air forces against the trailer and tow vehicle generated by other large vehicles. I have used several different types of WD hitches. I've used two different brands of round bar WD hitches, and two different versions of the Reese trunion bar hitches, both with the sway cams...the older one and now the newer one. I had better success with the older cam design. I had success to a lesser degree with the friction sway control devices.

I have no experience with the pivot point projection hitches (Hensly, ProPride, and the like), so I cannot comment on them. The thing that I dislike about them and keeps me from trying one along with the price, is the weight, and the comment I keep hearing that the trailer will "move around" using them. Just what does that mean, and how severe is it?

The only sure cure for sway that I have found to date is to slow down in windy conditions.
__________________
SteveH is offline   Reply With Quote
Old 06-04-2009, 08:46 AM   #74
Just an old timer...
 
85MH325's Avatar

 
Tipton , Iowa
Join Date: Mar 2003
Posts: 4,031
Images: 37
Steve, all trailers will exhibit sway at speed. The question is at what speed does the onset occur. The design challenges for trailer designers are to make that onset speed significantly higher than drivers will ever take them. The problems occur when because of trailer design, tow vehicle suspension design, tire issues, or loading issues the speed of onset of sway drops to at or below a normal cruising speed. Unfortunately, more factors come in to play than just the engineering design of the trailer; and those factors are further influenced by the design engineering of the tow vehicle, the condition of the components on the tow vehicle including the tires and entire suspension system, the hitch setup, the driver's steering input on the tow vehicle and the tow vehicle's wheelbase.

Obviously a long wheelbase tow vehicle would take longer to be critically affected by the trailer sway and be easier to correct. Rear overhang on the tow vehicle also has a significant role to play in how much leverage the trailer can gain over the tow vehicle's rear axle. An ideal tow vehicle would have a long wheelbase, short rear overhang, and dual wheels for maximum axle road adhesion. The further you get from those ideal tow vehicle specs, the more difficult it is to control a sway episode once one starts. The Hensley and Pro-Pride design hitches effectively fool the trailer's mass into acting directly on the axle plane rather than being able to use the rear overhang to leverage against the axle plane. From that perspective, they're excellent designs.

However, if you correct all of the potential issues in your rig that would cause a low-speed onset of sway, a standard WDH/anti-sway device hitch is perfectly adequate.

Here's a youtube video that's been posted here before that shows the speed of the onset of sway to be fairly low with an unladen utility trailer with a poorly placed axle position.

YouTube - Trailer Sway Control

All of the factors you mentioned can affect the onset of sway at speed if you are approaching and just under it's normal sway onset speed. The key is to identify them, fix them, and then not have to be concerned.

Roger
__________________
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"
85MH325 is offline   Reply With Quote
Old 06-04-2009, 09:46 AM   #75
The Silverdome
 
wiegabr's Avatar
 
2003 28' Classic
PEORIA , Illinois
Join Date: Mar 2009
Posts: 17
Thanks Andy for the posted document. There are several references to punishing the trailer. Would a product like the Air Safe do much to mitigate that between a 3/4 ton TV and a trailer with 800 lb hitch weight?
__________________
wiegabr is offline   Reply With Quote
Old 06-04-2009, 10:59 AM   #76
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 16,499
Images: 1
Quote:
Originally Posted by wiegabr View Post
Thanks Andy for the posted document. There are several references to punishing the trailer. Would a product like the Air Safe do much to mitigate that between a 3/4 ton TV and a trailer with 800 lb hitch weight?
Your welcome.

I do not have any working information about that product, therefore I cannot answer your question.

Andy
__________________
Inland RV Center, In is offline   Reply With Quote
Old 06-04-2009, 12:06 PM   #77
Rivet Master
 
SteveH's Avatar
 
2005 39' Land Yacht 390 XL 396
Common Sense , Texas
Join Date: Sep 2007
Posts: 5,311
Quote:
Originally Posted by 85MH325 View Post
Steve, all trailers will exhibit sway at speed. The question is at what speed does the onset occur. The design challenges for trailer designers are to make that onset speed significantly higher than drivers will ever take them. The problems occur when because of trailer design, tow vehicle suspension design, tire issues, or loading issues the speed of onset of sway drops to at or below a normal cruising speed. Unfortunately, more factors come in to play than just the engineering design of the trailer; and those factors are further influenced by the design engineering of the tow vehicle, the condition of the components on the tow vehicle including the tires and entire suspension system, the hitch setup, the driver's steering input on the tow vehicle and the tow vehicle's wheelbase.

Obviously a long wheelbase tow vehicle would take longer to be critically affected by the trailer sway and be easier to correct. Rear overhang on the tow vehicle also has a significant role to play in how much leverage the trailer can gain over the tow vehicle's rear axle. An ideal tow vehicle would have a long wheelbase, short rear overhang, and dual wheels for maximum axle road adhesion. The further you get from those ideal tow vehicle specs, the more difficult it is to control a sway episode once one starts. The Hensley and Pro-Pride design hitches effectively fool the trailer's mass into acting directly on the axle plane rather than being able to use the rear overhang to leverage against the axle plane. From that perspective, they're excellent designs.

However, if you correct all of the potential issues in your rig that would cause a low-speed onset of sway, a standard WDH/anti-sway device hitch is perfectly adequate.

Here's a youtube video that's been posted here before that shows the speed of the onset of sway to be fairly low with an unladen utility trailer with a poorly placed axle position.

YouTube - Trailer Sway Control

All of the factors you mentioned can affect the onset of sway at speed if you are approaching and just under it's normal sway onset speed. The key is to identify them, fix them, and then not have to be concerned.

Roger

Roger, no doubt a poorly loaded trailer of any type, meaning tail heavy, will sway faster, and after watching the video a few times, it's clear to me the driver accelerated the sway with steering input for the purposes of the video. I've seen that in the most current of Ford's anti-sway advertising also.

If the driver trys to steer away from the sway, the sway is exagerated. To stop the sway, the driver must steer into the sway.
__________________
SteveH is offline   Reply With Quote
Old 06-04-2009, 12:25 PM   #78
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 16,499
Images: 1
Quote:
Originally Posted by SteveH View Post
Roger, no doubt a poorly loaded trailer of any type, meaning tail heavy, will sway faster, and after watching the video a few times, it's clear to me the driver accelerated the sway with steering input for the purposes of the video. I've seen that in the most current of Ford's anti-sway advertising also.

If the driver trys to steer away from the sway, the sway is exagerated. To stop the sway, the driver must steer into the sway.
Since a sway can be very rapid, how do you determine which way is which?

How can someone, determine in less than one second, which way is into and which way is away from a sway?

If you are refering to a "skid", then that's a different story.

Andy
__________________
Inland RV Center, In is offline   Reply With Quote
Old 06-04-2009, 12:33 PM   #79
Rivet Master
 
SteveH's Avatar
 
2005 39' Land Yacht 390 XL 396
Common Sense , Texas
Join Date: Sep 2007
Posts: 5,311
It's very simple, Andy. You steer the same direction the trailer is taking your butt.

Sorry, but that's the best way I can discribe it. Steer the wrong direction, away from it, and I gurantee the oscillation will be increased.
__________________
SteveH is offline   Reply With Quote
Old 06-04-2009, 03:05 PM   #80
Just an old timer...
 
85MH325's Avatar

 
Tipton , Iowa
Join Date: Mar 2003
Posts: 4,031
Images: 37
Having experienced severe "sway" just once, I really don't want to do it again. "Sway" is not correctable through steering input because of the lack of reaction time; although as shown in the video, it can be induced through steering input.

The best way I can describe what happened in my circumstance was that I was towing a 15' fiberglass camper that weighed about 2500 lbs behind my 7500 lb Ford Excursion at 65 mph on a bare ball. The coupler spoon on the trailer (unbeknown to me) was worn, and on a particularly rough section of divided highway, the trailer decided to jump the ball. Fortunately I had chains connected. The electrical pigtail disconnected almost immediately, and I had no trailer brakes. I hit the controller and was quite surprised to find that there was no response from the trailer. I hadn't yet tumbled to the fact that the trailer was attached to the Excursion only by the safety chains.

I thought I had just a sway incident induced from the rough road, wind, road speed, and an unladen and unfamiliar travel trailer.

The best way I can describe what happened then is in terms of energy waves using wavelength and amplitude terms.

The trailer began to oscillate from side to side, and with the speed remaining constant (wavelength), the amplitude of the sway (side to side) got larger and larger with the constant input of energy from the forward motion. Fortunately because the Behemoth (the Excursion) was so heavy, the 2500 lb trailer was unable to dislodge the rear axle from the pavement.

The trailer at one point was at an angle to the Excursion of something over 45* and hopping from tire to tire at the far end of the swing to each side. It took up the entire left lane and the shoulder on the other side as I held the Excursion straight in the #2 east bound lane on the four-lane divided highway. Fortunately there was no one immediately behind me or next to me when it started.

I let off the gas, and as I slowed, the amplitude began to drop as the wavelength changed and the trailer began to come back in line with the Excursion and quickly settled back down on both tires. As I gently slowed and pulled to the side the trailer tongue, now suspended by merely one safety chain (the other had worn through), the tongue gently slid under the rear of the Excursion with the propane tank resting gently against the bumper.

The entire incident lasted something less than ten seconds although it seemed like an eternity, and I'm sure I hadn't covered more than a mile from start to finish and stop. I remember thinking that the very next hop of the trailer was going to roll it and I vaguely wondered if the trailer had enough "oomph" to roll the Excursion with it. I didn't know that it had actually become disconnected until after I got it stopped and got out to see what was going on.

In my estimation, four things saved me from having a rolled trailer. First, the weight and wheelbase of the Excursion didn't allow it to be moved. Second, I let off the gas immediately as soon as I recognized what was happening, but didn't brake. Third, that I'd properly set up the safety chains, and last that I didn't try to "steer out of it" but held the wheel straight and let the rig slow on its own.

In trying to figure out the "sway" propensity that my '94 tri-axle had behind my Excursion, I went through a lot of components until I figured out that the springs weren't heavy enough to keep the body centered over the rear axle. A set of radius rods and an aftermarket suspension anti-body roll bar as well as a shorter hitch ball-mount draw bar did wonders for that setup. Again, when the 34' acted up, because it was the truck suspension causing the problems to begin with, doing anything other than holding the steering straight caused lots of problems.

Just another lesson learned the hard way.

Roger
__________________
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"
85MH325 is offline   Reply With Quote
Old 06-04-2009, 03:21 PM   #81
Rivet Master
 
SteveH's Avatar
 
2005 39' Land Yacht 390 XL 396
Common Sense , Texas
Join Date: Sep 2007
Posts: 5,311
Quote:
Originally Posted by 85MH325 View Post
In trying to figure out the "sway" propensity that my '94 tri-axle had behind my Excursion, I went through a lot of components until I figured out that the springs weren't heavy enough to keep the body centered over the rear axle. A set of radius rods and an aftermarket suspension anti-body roll bar as well as a shorter hitch ball-mount draw bar did wonders for that setup. Again, when the 34' acted up, because it was the truck suspension causing the problems to begin with, doing anything other than holding the steering straight caused lots of problems.

Just another lesson learned the hard way.

Roger
I've recently thought about how a raduis rod, or panhard rod would help the stability of the rear of my tow vehicle while towing. Do you remember where you got them? I've been searching the aftermarket parts books that I have looking for something like that with no success.
__________________
SteveH is offline   Reply With Quote
Old 06-04-2009, 03:44 PM   #82
New Member
 
Currently Looking...
Oxnard , California
Join Date: May 2009
Posts: 1
Quote:
Originally Posted by Tom Nugler View Post
Thanks. Once again you’ve injected some reason and facts into the echo chamber so often common in enthusiast forums.
I’d like to offer a few comments into the mix. The owner’s manual for my 72 Tradewind has a section titled "Hitching Up". The illustrations show a Reese Dual Cam with Sway Control and the recommended procedure for making the adjustments to the draw head and bars.
Was the Reese WD hitch Airstream’s preferred choice? The Manual for the hitch was included with the literature that came with the trailer and the brackets are still on the tongue. The hitch is long gone.
There is a caution in that section, which reads:

If your car is equipped with adjustable load leveling air shocks, you must load the car first with typical luggage and passengers and bring it back to level. Then attach the trailer and adjust the load leveling bars. Otherwise the air shocks on your car will overload the rear wheels.

This appears to contradict the statement that air shocks should be disabled.
The Ford Expedition I use as my TV is rated at 6900# in it’s current configuration. It uses air bags as its springs. No leafs or coils. When set up as per the owner’s manual I have never experienced any sway in either of the trailers using a Draw-Tite round bar unit. I would have to suggest that a continuously variable, processor controlled air bag with functioning shocks would be the equivalent of a correctly sized metallic spring for a given load.
The only time I have ever had any diminished control was when a tire on the rear of a TV had a sudden loss of pressure at 60 MPH. That was the only time the tail wagged the dog.
The effect was startling but controllable. Would a Dual Cam have helped? I don’t know.

Just rambling as usual,
Tom.
I am a new user towing a 28 ft Safari with a Lincoln Navigator with automatic air bags but with an on/off switch on the passenger side slightly under the panel and on the right wall in front of the door. I followed the manual as to the set up instruction that you quote but after I set the vehicle level with the load in place, luggage, people, etc. and it leveled out then I turned off the auto air switch. Then lowered the Airstream tongue onto the hitch ball. The load is about 950 pounds max. The Airstream rides level but the rear of the Navigator is down. I have stabilizer etc. It towed 350 miles with no problems but my headlights are affected. Is this the right way or are the Airstream and the tow vehicle both supposed to be level to have proper weight distribution? The front axel of my airstream shows a greater load than the rear axel.
Jim Hawkins in Calfornia
__________________
jvhawkins is offline   Reply With Quote
Old 06-04-2009, 04:28 PM   #83
Just an old timer...
 
85MH325's Avatar

 
Tipton , Iowa
Join Date: Mar 2003
Posts: 4,031
Images: 37
Quote:
Originally Posted by SteveH View Post
I've recently thought about how a raduis rod, or panhard rod would help the stability of the rear of my tow vehicle while towing. Do you remember where you got them? I've been searching the aftermarket parts books that I have looking for something like that with no success.
Steve, what is your tow vehicle? My LANDYOT radius rods were custom made by a machinist who turned Excursion radius rods into a cottage industry. The sway bar was by Hellwig.

At the very least, I'd recommend the Hellwig rear sway bar on any tow vehicle.

Roger
__________________
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"
85MH325 is offline   Reply With Quote
Old 06-04-2009, 04:32 PM   #84
Just an old timer...
 
85MH325's Avatar

 
Tipton , Iowa
Join Date: Mar 2003
Posts: 4,031
Images: 37
Quote:
Originally Posted by jvhawkins View Post
I am a new user towing a 28 ft Safari with a Lincoln Navigator with automatic air bags but with an on/off switch on the passenger side slightly under the panel and on the right wall in front of the door.

The load is about 950 pounds max. The Airstream rides level but the rear of the Navigator is down. I have stabilizer etc.

Is this the right way or are the Airstream and the tow vehicle both supposed to be level to have proper weight distribution?

Jim Hawkins in Calfornia
Jim, not to hijack your question... and I'm sure someone more knowlegeable than I can answer... but a couple of questions...

1) What is your Navigator rated to tow, and what is it's maximum hitch weight?

2) What does the Navigator's owner's manual say about how the auto-leveling suspension is supposed to be used while towing?

3) What brand and style of hitch are you using?

If you can answer those, I'm sure someone will be able to help.

Roger
__________________

__________________
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"
85MH325 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
MPG difference between towing and not-towing? yiesyisyeno Tow Vehicles 11 09-01-2008 03:35 PM
No towing for me. lendoyle Member Introductions 3 08-30-2006 10:22 AM
Towing philipl411 Classic Motorhomes 1 07-14-2005 01:02 AM
Towing - 1965 65trotter 1965 - 1969 Globetrotter 9 08-10-2003 10:19 AM
Good towing/Bad towing! ViewRVs Hitches, Couplers & Balls 5 03-09-2003 08:37 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 07:49 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.