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Old 12-17-2014, 08:28 AM   #15
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To add fuel to the fire, the newer trailers don't have the steel hold down plate at the rear, which makes them even weaker at the rear. Even with the hold down plate, the connection between the shell and frame has always been weak. If they were properly connected every few inches all the way around the shell, then you could hang a motorcycle off the back and not hurt anything. Or you an make a real beefy frame that is strong enough by itself and not worry about the connection. An Airstream is no where near as strong as an airplane structure but it could be. Suction cups or some other attachment to the shell is a wise choice to remove some of the load off the frame.

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Old 12-17-2014, 10:51 AM   #16
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thanks for all of your thoughts and concerns, i do appreciate the collected knowledge. didn't mean to come across as defensive at all. what i hoped to do was clarify just how the AS rack is mounted and compare that to what i fabricated. i did take some time to examine the AS rack at the dealership who had it mounted on a full scale display complete with the rear sheet metal. i got a good look at the configuration of the assembly.

the biggest difference will be the bikes on the Yakima rack will ride lower and about 14" further to the rear. the Yakima rack, as already pointed out, has a captured nut inside the structure. you actually bolt the rack to the receiver so virtually no movement, bouncing, twisting, etc. occurs with the rack mounted this way. the bikes are also secured, top and bottom, to keep them from moving around.

how the trailer is put together is news to me so before we start travelling, i will take a bunch of jpegs of the rear of the trailer from above and below and watch for any separation that may occur. hard to believe that as a possibility, but your 'heads up' will have me watching that closely.

thanks again for the input.
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Old 12-17-2014, 11:53 AM   #17
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Just so you are aware, the farther the bikes are mounted behind the trailer the greater the greater the moment arm, or stress on the frame/shell connection when the trailer moves over road dips.
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Old 12-17-2014, 11:58 AM   #18
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I'll second what Brian said. I installed a front mounted receiver and carry two bikes in front of my Tundra, making sure the handlebars are facing the curb side. After a few miles, I hardly notice them. One other advantage—if the bike rack gets loose or starts to fail, I can see it in time to prevent damage.
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Old 12-17-2014, 01:16 PM   #19
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GPT, you've made your decision and that is fine. I wish you the best of luck with both the bike rack and your Airstreaming career. Let me suggest that you report back on this thread after you've used the bike rack and towed your trailer with it for awhile and let us know how it's going. Keep in mind that the kind of frame separation caused by frame mounted racks that others have been cautioning you about can take quite some time and many miles to show itself. So if your usage is relatively short and/or infrequent you may never see any problems which would of course be fine.

By the way, we carry our four bikes (2 road and 2 mountain) in a specially designed bike rack under the cap of my pickup.
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Old 12-17-2014, 01:22 PM   #20
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Oh, one last thing. Given the RV industry's reputation for less than bullet proof engineering (Airstream and Thor are sadly included in this indictment) I would find little comfort in simply copying the "Airstream approved" bike rack design. It wouldn't surprise me to see them pulling that rack off the market in a couple of years due to some unforeseen issue with the design.

"Bullet proof engineering" was one reason why we opted to carry our bikes in the truck bed.
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Old 12-17-2014, 01:24 PM   #21
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I'll second what Brian said. I installed a front mounted receiver and carry two bikes in front of my Tundra, making sure the handlebars are facing the curb side. After a few miles, I hardly notice them. One other advantage—if the bike rack gets loose or starts to fail, I can see it in time to prevent damage.
We briefly considered a front mounted hitch rack for our bikes but decided that the exposure to the elements (e.g., rain, road grime & bugs) would not be good for the bikes so we opted for the enclosed storage in the truck bed. If you are just hauling some casual "beach cruisers" the front mount could work.
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Old 12-17-2014, 01:31 PM   #22
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Oh, one last thing. Given the RV industry's reputation for less than bullet proof engineering (Airstream and Thor are sadly included in this indictment) I would find little comfort in simply copying the "Airstream approved" bike rack design. It wouldn't surprise me to see them pulling that rack off the market in a couple of years due to some unforeseen issue with the design.

"Bullet proof engineering" was one reason why we opted to carry our bikes in the truck bed.

I've been intrigued since this thread started about this very thing, with the Fiamma. I've been looking at it more closely, and it does not appear to have as much vertical support to "unify" the shell and frame as I thought. The upper brackets look like they swivel- which is counter intuitive to what I thought was going on...

Maybe it's "Airstream Approved" because of the weight? i.e. 21 lb rack, with 77 lb max limit. The highlighted claim is that it is less than 100 lbs. I'm not getting the magic that i thought I understood.

Makes me think I should just work on my shell-to-frame reinforcement and go with hitch mount
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Old 12-17-2014, 01:57 PM   #23
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We briefly considered a front mounted hitch rack for our bikes but decided that the exposure to the elements (e.g., rain, road grime & bugs) would not be good for the bikes so we opted for the enclosed storage in the truck bed. If you are just hauling some casual "beach cruisers" the front mount could work.
Good point, Ours are indeed "beaters!" A couple of cheapie mountain bikes that we bought almost 20 years ago. It would be nice to have fancy high tech road bikes, but in our case we really only use them on RV trips and even then not a whole lot.

I suppose one advantage of old bikes like ours is that it is unlikely people would choose to steal them - but if they did, I would likely just go to a local pawn shop wherever we happened to be and pick up a couple more for next to nothing!

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Old 12-17-2014, 02:04 PM   #24
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Makes me think I should just work on my shell-to-frame reinforcement and go with hitch mount
I'd be real careful with a frame mounted hitch for your bike rack. You may be able to reinforce the attachment point to the frame so that connection is "bullet proof" but you are still attaching to an Airstream frame that flexes as you bounce down the road. The problem with frame mounted hitches for bike racks (or any other cargo such as generators, etc...) is not that the hitch itself separates from the frame but rather than the added weight at the very end of the frame causes the frame's flexing to increase beyond Airstream's design parameters the result being that the body of the Airstream separates from the frame. 100 lbs of weight may not seem like much on a 5-6,000 lbs trailer, but try holding a 5 or 10 lbs weight at arms length in front of you for any length of time and you'll get the picture.
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Old 12-17-2014, 02:23 PM   #25
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Question, just curious, a 34' trailer has much more frame behind the rear axles than say, a 28'. Any load in the rear of these trailers would push down on the floor, thus the frame. The C channel being on top frame with bolts going through it, the floor, and into the outriggers.

How is a rear receiver with attachments any different on a 28' airstream than all the weight that would theoretically be well aft of this point in space if it was a 34'? Obviously the 34 would have more steel, but a longer moment arm.

I would think, the shorter the trailer the shorter the moment arm, and thus the less likely there would be any complications.

In my case I have a new frame made with 1/4 " tube steel main rails, i will have a receiver put on mine one day but that's a different animal altogether.






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Old 12-17-2014, 03:40 PM   #26
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Originally Posted by Mixter View Post
I've been intrigued since this thread started about this very thing, with the Fiamma. I've been looking at it more closely, and it does not appear to have as much vertical support to "unify" the shell and frame as I thought. The upper brackets look like they swivel- which is counter intuitive to what I thought was going on...

Maybe it's "Airstream Approved" because of the weight? i.e. 21 lb rack, with 77 lb max limit. The highlighted claim is that it is less than 100 lbs. I'm not getting the magic that i thought I understood.

Makes me think I should just work on my shell-to-frame reinforcement and go with hitch mount
The Airstream bike rack holds the bikes cantilevered behind the bumper/frame attachment, so the force imposed by a dip in the road is felt as a rotational force, trying to roll the assembly away from the Airstream shell. The two upper supports attached to the shell do not resist vertical load, they resist rotational force away from the trailer.

Sound engineering I think, but then I have been just a poor working stiff with an inclination towards the arts, not an engineer.
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Old 12-17-2014, 03:42 PM   #27
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Question, just curious, a 34' trailer has much more frame behind the rear axles than say, a 28'. Any load in the rear of these trailers would push down on the floor, thus the frame. The C channel being on top frame with bolts going through it, the floor, and into the outriggers.

How is a rear receiver with attachments any different on a 28' airstream than all the weight that would theoretically be well aft of this point in space if it was a 34'? Obviously the 34 would have more steel, but a longer moment arm.

I would think, the shorter the trailer the shorter the moment arm, and thus the less likely there would be any complications.

In my case I have a new frame made with 1/4 " tube steel main rails, i will have a receiver put on mine one day but that's a different animal altogether.

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Having helped to disassemble a vintage Airstream and having had numerous conversations with Colin Hyde on the subject, I am familiar with how these trailers are put together and understand how the frame and body can get separated over time. Sometimes this results from a rusted frame or rotted floor which detaches from the C channel and, at other times, a perfectly good frame flexes so much that the bolts and rivets that hold the "C channel" to the frame and body fail causing those components separate. All things being equal, increased weight at the extreme rear of the trailer (such as caused by a loaded bike or cargo rack) increases the frame's flex and thus the chance that the C channel will fail.

You might be tempted to think that a trailer with a longer rear overhang would be subject to more flex and thus more separation than would a short trailer. However, the frames on longer trailers are stiffer than on short trailers. The stock frames on Airstreams of all lengths can and do flex. The amount of flex in any given frame is related to the length of the pivot, the weight applied and the strength of the steel used in construction. For this reason, it's too simplistic to think that rear end separation is not a problem that can happen with shorter trailers.

If you have significantly stiffened your frame during a frame-off restoration, it is entirely possible that you can carry the added weight of a loaded bike rack on the rear of your trailer and not suffer any ill effects. Best of luck!
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Old 12-17-2014, 04:28 PM   #28
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I've been intrigued since this thread started about this very thing, with the Fiamma. I've been looking at it more closely, and it does not appear to have as much vertical support to "unify" the shell and frame as I thought. The upper brackets look like they swivel- which is counter intuitive to what I thought was going on...

Maybe it's "Airstream Approved" because of the weight? i.e. 21 lb rack, with 77 lb max limit. The highlighted claim is that it is less than 100 lbs. I'm not getting the magic that i thought I understood.

Makes me think I should just work on my shell-to-frame reinforcement and go with hitch mount

i have to say that after seeing the Fiamma at the dealership in full mock-up with the rear sheet metal, you are correct, it is bolted to the frame rails in pretty much the exact same position as what i fabricated. the two 'arms' that contact the rear of the trailer are pressure mounts, they are not through bolted to anything, maybe springs inside to keep them in contact, i don't know. if you check out the photos, you will see what i mean. i think these 'arms' are meant to eliminate fore-aft rocking but if that is true, your exterior sheet metal is going to take a beating.

when you bolt the Yakima rack i have into the receiver, there is no fore-aft motion. the bikes sit on arms with rubber hold downs and then are further secured to the rack with 'C' hooks through the wheels and back to the rack. i have used this rack over and over again and i can tell you the bikes simply don't move around.

true enough, my system moves the bikes back, probably 14-16" but composite bikes don't weight much and it gives me the option of putting the carrier on the truck and going someplace interesting to ride.

i will, however, be watching the rear frame rails closely.
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