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09-11-2011, 08:46 PM
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#61
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Rivet Master
1997 34' Limited
1970 27' Overlander
South of Atlanta
, Georgia
Join Date: Sep 2009
Posts: 1,709
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Terry,
What year marked the change to a heavier frame?
__________________
Craig and Carol
1997 34' Excella 1000
1970 27' Overlander, International
2009 Ford F150 5.4L
ProPride hitch with 1400# bars
AIR 41028
TAC GA-8
WBCCI 10199
Past President Southeastern Camping Unit (12)
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09-12-2011, 10:24 AM
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#62
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Rivet Master
2006 22' International CCD
2007 Base Camp
Elk Valley
, British Columbia
Join Date: Jan 2009
Posts: 657
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Quote:
Originally Posted by Inland RV Center, In
No, not exactly.
The principal method of construction, of an aircraft is called "monocoque".
Since an Airstream is not totally rounded, it's design is called "semi-monocoque".
Monocoque, as defined by Webster, "is a load bearing shell".
Therefore, the shell supports the frame.
That is also why an Airstream frame can and is very weak, in comparison to SOB trailers.
Andy
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Or, buy your definition, the shell only semi-supports itself... it would seem that some of them cannot support their own weight at all...
Maybe it more accurate to call it a 'Unibody', where the 'frame' and 'shell' are integral units.
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09-12-2011, 10:48 AM
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#63
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Rivet Master
Airstream Dealer
Corona
, California
Join Date: Feb 2002
Posts: 16,497
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Quote:
Originally Posted by Friday
Or, buy your definition, the shell only semi-supports itself... it would seem that some of them cannot support their own weight at all...
Maybe it more accurate to call it a 'Unibody', where the 'frame' and 'shell' are integral units.
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It's not my difinition, but it is Airstream's definition.
Always has, always will.
Andy
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09-12-2011, 11:24 PM
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#64
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Rivet Master
2006 22' International CCD
2007 Base Camp
Elk Valley
, British Columbia
Join Date: Jan 2009
Posts: 657
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One more question/observation... my 2006 has 'wheelie bars' on the back... smaller metal wheels meant to catch the back before it hits the ground... they seem to need very little slope before they come into action (I think they are too low myself)... but... they are part of a rear crossmember that includes my 2 inch receiver, and the 2 rear levelling jacks. It sure seems like a factory installation... any insight onto whether that vintage might have come with those features? Or I am looking at some type of add-on?
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09-12-2011, 11:29 PM
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#65
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Rivet Master
Airstream Dealer
Corona
, California
Join Date: Feb 2002
Posts: 16,497
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Quote:
Originally Posted by Friday
One more question/observation... my 2006 has 'wheelie bars' on the back... smaller metal wheels meant to catch the back before it hits the ground... they seem to need very little slope before they come into action (I think they are too low myself)... but... they are part of a rear crossmember that includes my 2 inch receiver, and the 2 rear levelling jacks. It sure seems like a factory installation... any insight onto whether that vintage might have come with those features? Or I am looking at some type of add-on?
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Airstream has never installed rear wheels.
They are a hazard to the trailer.
Hit the pavement with one of those rear wheels and watch how fast the rear quarter panel gets damaged.
Take them off!!!!
That's why Airstream installed rear skid plates.
Andy
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09-13-2011, 05:54 AM
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#66
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Rivet Master
2005 30' Classic
Burlington
, Ontario
Join Date: Sep 2008
Posts: 2,743
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Quote:
Originally Posted by Inland RV Center, In
Airstream has never installed rear wheels.
That's why Airstream installed rear skid plates.
Andy
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If the wheels can cause quarter panel damage, would I be right in assuming that the skid plates would cause the same damage if they were to contact, the difference being that the wheels are likely much lower than the skid plates and and therefor that much more likely to contact the road surface?
Brian.
__________________
Brian & Connie Mitchell
2005 Classic 30'
Hensley Arrow / Centramatics
2008 GMC Sierra SLT 2500HD,4x4,Crew Cab, Diesel, Leer cap.
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09-13-2011, 12:13 PM
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#67
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Rivet Master
2006 22' International CCD
2007 Base Camp
Elk Valley
, British Columbia
Join Date: Jan 2009
Posts: 657
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The wheels are low enough than when I back in beside my house, they dig in a bit to the gravel/grass area because of the slope. As I mentioned, the receiver and rear levelling jacks are all part of this same contraption... if it's not OEM, someone sure did a nice job with it.
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09-13-2011, 01:16 PM
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#68
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Rivet Master
Airstream Dealer
Corona
, California
Join Date: Feb 2002
Posts: 16,497
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Quote:
Originally Posted by Wingeezer
If the wheels can cause quarter panel damage, would I be right in assuming that the skid plates would cause the same damage if they were to contact, the difference being that the wheels are likely much lower than the skid plates and and therefor that much more likely to contact the road surface?
Brian.
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Rarely, as many thousands can attest to.
Andy
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09-13-2011, 02:18 PM
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#69
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Rivet Master
Currently Looking...
Mantua
, Ohio
Join Date: Jul 2005
Posts: 7,062
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Leveling jacks on the rear sounds interesting?! jim
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09-13-2011, 02:20 PM
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#70
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Rivet Master
1959 17' Pacer
Long Beach
, California
Join Date: Mar 2011
Posts: 920
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Quote:
Originally Posted by Inland RV Center, In
Rarely, as many thousands can attest to.
Andy
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I'm not familiar with the newer models. So either the skid plates must be larger and dispersing the same road force over a greater area than that of the wheels, or it is another moment arm problem in that the wheels are set farther back than the skid plates are/would be, so the pivot from the axle is a longer distance, providing more force, and on the bumper as opposed to the frame rails? Or a combination of both?
- Peter
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09-13-2011, 10:38 PM
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#71
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Rivet Master
2006 22' International CCD
2007 Base Camp
Elk Valley
, British Columbia
Join Date: Jan 2009
Posts: 657
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Quote:
Originally Posted by zigzagguzzi
Leveling jacks on the rear sounds interesting?! jim
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How so? I thought most trailers had them on all 4 corners, no? Our Basecamp only had them on the back... I guess to keep it from tipping when unhooked from the TV...
Since they aren't really able to 'level' the trailer, I think maybe the term 'stabilizing jack' is better for the A/S... just keeps it from wobbling around so much if you have some heavy-steppers inside.
I'm considering grinding off the wheels... but need to consider what I am going to replace them with... Any photos of the newer models 'skids' on the back?
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09-14-2011, 06:10 AM
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#72
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Rivet Master
Currently Looking...
Mantua
, Ohio
Join Date: Jul 2005
Posts: 7,062
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Yes they stabilize not level, hence my comment, jim
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09-14-2011, 02:05 PM
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#73
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Rivet Master
2015 28' Flying Cloud
Durango
, Colorado
Join Date: Oct 2010
Posts: 623
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Bikes, Shells and Frames
Quote:
Originally Posted by Inland RV Center, In
No, not exactly.
Monocoque, as defined by Webster, "is a load bearing shell".
Therefore, the shell supports the frame.
Andy
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Well, it's a rainy day in Durango, so I'll add my 2 cents worth.
Monocoque (single shell) is a construction technique that supports structural load by using an object's exterior, as opposed to using an internal frame. A kayak is an example of monocoque construction. Airstream currently builds a double shell with framing between skins. They call it semi-monocoque, as it doesn’t wrap completely around (under) the unit like an airplane, although it is actually a double hull on a deck. The shell does not support the undercarriage frame, it supports itself and accessory items (air conditioner, cabinets etc.) The shell is attached to and carried by the undercarriage frame. Excessive flexing of the frame could cause problems with the relatively inflexible shell. How strong & rigid is the undercarriage frame? My 2011 is obviously strong enough for the rear sliders to take a substantial force. So why doesn’t Airstream provide framing for a bike carrier, or prescribe attachment points for a bike carrier similar to their prescribed jacking points? I guess it’s the same reason that they don’t offer many buyer options, or respond to buyer requests for substitutions such as larger batteries, larger wheels & tires etc. Apparently they can’t be bothered.
My A/S dealer was quite confident in offering to custom install a receiver hitch. For my type of bike usage, however, a tow vehicle roof rack carrier is a better solution.
__________________
Safe Travels,
Joe & Joan Donnaway
Durango, CO
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09-14-2011, 02:14 PM
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#74
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Rivet Master
Airstream Dealer
Corona
, California
Join Date: Feb 2002
Posts: 16,497
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Quote:
Originally Posted by JamuJoe
Well, it's a rainy day in Durango, so I'll add my 2 cents worth.
Monocoque (single shell) is a construction technique that supports structural load by using an object's exterior, as opposed to using an internal frame. A kayak is an example of monocoque construction. Airstream currently builds a double shell with framing between skins. They call it semi-monocoque, as it doesn’t wrap completely around (under) the unit like an airplane, although it is actually a double hull on a deck. The shell does not support the undercarriage frame, it supports itself and accessory items (air conditioner, cabinets etc.) The shell is attached to and carried by the undercarriage frame. Excessive flexing of the frame could cause problems with the relatively inflexible shell. How strong & rigid is the undercarriage frame? My 2011 is obviously strong enough for the rear sliders to take a substantial force. So why doesn’t Airstream provide framing for a bike carrier, or prescribe attachment points for a bike carrier similar to their prescribed jacking points? I guess it’s the same reason that they don’t offer many buyer options, or respond to buyer requests for substitutions such as larger batteries, larger wheels & tires etc. Apparently they can’t be bothered.
My A/S dealer was quite confident in offering to custom install a receiver hitch. For my type of bike usage, however, a tow vehicle roof rack carrier is a better solution.
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Your opinion as to what supports what, is different from thta of the Airstream engineers.
Andy
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09-14-2011, 04:57 PM
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#75
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3 Rivet Member
1989 29' Excella
Tyrone
, Georgia
Join Date: Jan 2011
Posts: 187
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I have never even seen one shell off but I'm willing to bet 1) the frame is kind of floppy by itself (relative to other trailer frames) and 2) the shell is kind of floppy by itself. Sounds like it's an airstream not monocoque or semimonocoque or unibody.
However, concerning the engineers I would only question why 1) all the rear bath models from the 70's have an inherent structural flaw and 2) why the new ones are not easily capable of carrying 50 pounds 5 feet further aft than they can admittedly carry a 100 pound a/c unit. (another inherent structural flaw).
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09-14-2011, 07:06 PM
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#76
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Retired.
Currently Looking...
.
, At Large
Join Date: Jun 2003
Posts: 21,276
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Quote:
Originally Posted by Aviator
Terry,
What year marked the change to a heavier frame?
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They started getting stronger in the mid 1980's, when they went to a full box channel frame from a C channel. They've gotten progressively more robust over the years, and the advent of the wide-body trailers and slide out models actually had frames that are worthy of the name.
One day when I don't have anything better to do, I'll take some measurements of metal thickness (gauge), height, and width of the frames of some of the trailers of different vintages we have on the lot.
__________________
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.
Terry
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09-14-2011, 07:16 PM
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#77
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Rivet Master
1988 25' Excella
1987 32' Excella
Knoxville
, Tennessee
Join Date: Oct 2010
Posts: 5,103
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sometimes we think of a trailer as a fairly rigid frame (rails) with a box sitting on the frame. like a flatbed with a box sitting on it. and with the bumper on the frame rails. But think aboutt this. on the truck you have to strap the box down to keep it from bouncing. In the Airstream the c flange is the strap and it is under tension during part of the bounce. I think the frame/body seperation occurs where the body is attached to the c channel flange. The rivets pull or the flange shears. The frame of the airstream is tapered and lightened to the back. The body is fairly rigid with its skins and ribs and rivets. As long as you are pushing down on the body to the frame, like adding and airconditioner, you are okay as long as you are within design limits. And you might get a little cushioning from some flex in the body. But sometimes in a bounce the body is headed up, pulling away from the frame. or the back of the frame bounces down against the rigid part of the body. Additional weight on the bumper or frame would tend to act as a hammer and increase the force.
The frame damage occurs out at the bumper, not in towards the axle. What I do think is that adding a weight that is bouncing up and down to the bumper can directly increase the pressure to seperate the body and the floor at the back.
Another factor is the extreme rear is a bad place to put weight balance wise. I have seen Airstreams with bicycles on the back. It does work. I probably would not do it. The frame seperation I have seen occurs on the rear and the front of the very long trailers. Saw some people repairing a 34 foot in the front corner.
Camped next to a Airstream in Florida two years ago that had a bicycle rack that went between the propane tank cover and the front of the trailer and held one or maybe 2 bikes. He said it was a commercial rig. worked well. I was suprised there was enough room but it seemd to be fine.
My 88 model refers to the bumper area as the sewer hose storage compartment. Sewer hoses are not real heavy.
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09-14-2011, 07:36 PM
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#78
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Rivet Master
2012 28' International
Currently Looking...
New Orleans
, Louisiana
Join Date: Apr 2002
Posts: 2,077
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I agree with Andy, but every time this topic pops up I have post this picture.
__________________
Jim N5TJZ Air# 174
2012 International Serenity 28
2005 Safari 25 SS Traded
1968 Globetrotter Sold
2011 F150 Ecoboost
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09-14-2011, 09:01 PM
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#79
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Rivet Master
2006 22' International CCD
2007 Base Camp
Elk Valley
, British Columbia
Join Date: Jan 2009
Posts: 657
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I'd like to agree with Andy more... as he obviously has a lot of experience in the industry... but I find the random "Because the Caravaner study said..." or "Because the Airstream engineers said..." to be a bit hollow when the source isn't cited.
The whole 'why do Airstreams crash' is a good example... Andy cites 'air bags' as a huge factor... that so many of the crashes were using air bags... OK, but how many tow vehicles all-together are using air bags safely? If 50% of the travelling trailers are running bags on the tow vehicle... I'd expect them to be found on 50% of the trailers that wreck. 1/2 the statistic doesn't prove anything.
My A/S has a large "jack here" sticker under the rear corner... right beside my wheelie-wheel... who engineered THAT? Or is that an after-market sticker?
Puzzled...
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09-14-2011, 09:30 PM
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#80
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2 Rivet Member
2005 31' Classic
2005 31' Classic
Douglass
, Texas
Join Date: Sep 2009
Posts: 91
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Here is how I solved it. Bought the front mount 2" receiver at, e-hitches.com for $130.00.
__________________
James Rudd
2001 25' Safari
2003 Dodge 2500
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