The Trunk

[Wild-Air]

As we know, Airstreams are quite limited in external storage capacity. Someplace to put the BBQ grill, somewhere for the folding chairs, and where does the gas for the generator go? And the generator?

With that in mind, I designed a platform to mount an external removable storage trunk. Of course, it had to be aluminum and it had to have a minimal footprint. With those thoughts in mind, and using the two frame-mounted 2" receiver hitches I had installed at George Sutton RV when I bought the trailer, I set out to put this trunk idea together.

After much searching and researching, I found a tool chest that met my needs and then located a local fabricator to build the platform. Once the trunk was mounted, I started throwing stuff in there - a shovel, umbrellas for the chairs, the chairs, the grill, hoses, a power cord, a hydraulic jack, you know - stuff. As you can see from the pictures, it came out just great.

[2005 ford]

Very nice. That was a great idea for the two hitch receivers. Maybe you could sell the idea to Airstream. Do you have any concerns with the weight hanging off the back end? If I remember correctly there has been threads on mounting bicycle racks on the back with all sorts of watch outs regarding weight. I would think with your setup the receivers are attached to the frame and therefore much stronger then a bumper mount.

[ROBERT CROSS]

GREAT looking set-up Russ!!!

Foolish to ask but any provisions for the rear license plate?

Remember your tongue weight when the trunk is full.

Bob

[Inland RV Center, In]

Originally Posted by Wild-Air

As we know, Airstreams are quite limited in external storage capacity. Someplace to put the BBQ grill, somewhere for the folding chairs, and where does the gas for the generator go? And the generator?

With that in mind, I designed a platform to mount an external removable storage trunk. Of course, it had to be aluminum and it had to have a minimal footprint. With those thoughts in mind, and using the two frame-mounted 2" receiver hitches I had installed at George Sutton RV when I bought the trailer, I set out to put this trunk idea together.

After much searching and researching, I found a tool chest that met my needs and then located a local fabricator to build the platform. Once the trunk was mounted, I started throwing stuff in there - a shovel, umbrellas for the chairs, the chairs, the grill, hoses, a power cord, a hydraulic jack, you know - stuff. As you can see from the pictures, it came out just great.

Keep in mind the "moment arm" weight that you added.

Multiply the weight times the distance in feet from the rear axle. That's the moment arm.

Then, since the shell holds up the frame, see how many pounds your now asking the rear of the shell to support.

Don't be surprised if in short order, the rear end will show considerable damage.

And by the way, when the trailer hits a bump in the road, that weight multiplies very quickly.

Indeed, the add-on looks great, the fact remains that an Airstream is not built to handle that new load.

That's why the spare tire is carried up front, as even it's weight on the rear, causes damages.

Andy

[switz]

I sure hope that neat looking setup works okay when loaded.

I was told to not put my tools aft of the wheels (I thought that would slightly lighten the tongue weight). Using the axles as a fulcrum might stress the shell overhead if the ends try to sag downward at the same time.

Airstream barely allows a pair of bicycles hanging on the rear of their trailers.

[Wild-Air]

Thanks for the compliments and concerns. I'm not an engineer, but I am a former Class A driver, and after loading it up and taking the trailer out on Memorial Day weekend, it handled great. I drove up Hwy 50 from Carson City (4,600') to Spooner Summit (7,100') then to Lake Tahoe (6,200') and then back down this past Memorial Day weekend.

The polar moment identified by Andy is important and was certainly a design consideration. The amount of weight on the tongue with 110 pounds of propane bottles, 50 pounds of spare tire, and 70 pounds of batteries helps make the tongue weight come in at about 11% of the full gross weight rating of the trailer. That's a lot of weight bearing down on the vehicle hitch for a non-grossed out trailer. Having the substantial tongue weight offset some was desired, but then again, if the trunk becomes a burden it takes pulling out two pins and it's off.

The fear of having the trailer shell come apart because the frame is elongated was not a consideration, but I'll keep it in mind. In the mean time, I'll be testing it locally and reporting back what issues or not I encounter. iIt's probably not a modification for everyone, but I've always been a bit of a free thinker.

Thans again for the comments, suggestions and concerns!

[Wild-Air]

Originally Posted by ROBERT CROSS

GREAT looking set-up Russ!!!

Foolish to ask but any provisions for the rear license plate?

Remember your tongue weight when the trunk is full.

Bob

You're right, Robert. The license plate needs a new home. For now, it'll be hung off the rear of the platform, but a light still needs to be rigged. It's getting closer...

[Wild-Air]

Originally Posted by Inland RV Center, In

Keep in mind the "moment arm" weight that you added.

Multiply the weight times the distance in feet from the rear axle. That's the moment arm.

Then, since the shell holds up the frame, see how many pounds your now asking the rear of the shell to support.

Don't be surprised if in short order, the rear end will show considerable damage.

And by the way, when the trailer hits a bump in the road, that weight multiplies very quickly.

Indeed, the add-on looks great, the fact remains that an Airstream is not built to handle that new load.

That's why the spare tire is carried up front, as even it's weight on the rear, causes damages.

Andy

Thanks for your concern and expertise, Andy. The frame not being suitable to support the shell was not something I was aware of. I understood the shell formed somewhat of a monocoque due to the ribs being attached across the frame, but I didn't know the roof was a stressed member front to rear. I wonder if that's why my cabinets have never lined up properly.

[Len n Jeanne]

This add-on looks great. Our solution to limited storage space is a pickup truck with a crew cab and cap/canopy on the back. We get all kinds of camping gear in it.

[Inland RV Center, In]

Originally Posted by Wild-Air

Thanks for your concern and expertise, Andy. The frame not being suitable to support the shell was not something I was aware of. I understood the shell formed somewhat of a monocoque due to the ribs being attached across the frame, but I didn't know the roof was a stressed member front to rear. I wonder if that's why my cabinets have never lined up properly.

Russ.

It's the other way around.

The shell was not designed to hold "UP" the additional weight of the trunk and contents, and any additional weight that you may have added to the frame.

You will see in time, how the frame will want to drop away from the shell.

The more weight you add, the more severe the issue becomes.

Think of a crow bar. The longer the handle, the easier the effort becomes. What you have added, is a much longer handle to the crow bar, or much more weight to the "moment arm".

If you wish, take the total weight that you added, and multiply it by the distance in feet from the rear axle.

That, sitting still, is the moment arm weight that you added, and when hitting a bump, that weight multiplies.

The way that the shell is attached to the frame, which is how it holds up the frame, will simply not handle that additional weight.

As Airstream also states, "NOT EVEN A SPARE TIRE WEIGHT".

I don't wish to alarm you, but only to make you aware of the consequences.

Happy Airstreaming is always the word, or at least should be.

Andy

[perryg114]

The frame will drop away from the shell because Airstream did a crappy job of joining the frame and shell together. The only place there is anything resembling a structural attachment between the shell and the frame is at the front and rear of the trailer. Since the contact points are not very good, things start to pull loose. Airstream found this out in the 70's when they started adding large holding tanks to rear bathroom models. That combined with corrosion and rot problems leads to rear end separation. The shell and frame can support alot more than they do if the contact between the shell and frame were better. I am with Andy on this. You may get by with it for a while but it may lead to problems.

Perry

[Inland RV Center, In]

Originally Posted by perryg114

The frame will drop away from the shell because Airstream did a crappy job of joining the frame and shell together. The only place there is anything resembling a structural attachment between the shell and the frame is at the front and rear of the trailer. Since the contact points are not very good, things start to pull loose. Airstream found this out in the 70's when they started adding large holding tanks to rear bathroom models. That combined with corrosion and rot problems leads to rear end separation. The shell and frame can support alot more than they do if the contact between the shell and frame were better. I am with Andy on this. You may get by with it for a while but it may lead to problems.

Perry

Adding to the quickness of the damages is lack of PROPER running gear balance.

Andy

[perryg114]

You did a very good job on the box.

Perry

[bredlo]

Originally Posted by ROBERT CROSS

Foolish to ask but any provisions for the rear license plate?

Originally Posted by Wild-Air

You're right, Robert. The license plate needs a new home.

The first thing I thought of as a solution would be a flip-up holder that doesn't require additional holes, but simply moves up and down like a flatscreen tv-type bracket.

I looked around, and while there are lots of flip-down models for hiding hitches, gas tank fillers, etc. There's even a wired version that lets Corvette owners hide their front plate underneath the bumper with the push of a button on their keychain.

But the only one I could find that keeps the plate facing the same direction, simply moving it up and down via a spring-loaded frame, was from Summit Racing: http://www.summitracing.com/parts/sum-g301000

Unfortunately, it seems to have been discontinued, and I can't find anything like it, anywhere. Too bad, as I would've bought one myself to sit above the spun aluminum spare tire carrier we'll eventually install.

[withidl]

For what it's worth, adding weight to the rear of my 2002 ASCL 31' hasn't affected the structure after 35,000+ miles where I have at times found drawers open and occasionally on the floor from hitting highway irregularities.

I load my tools, bottle jack, cables, hoses, etc. in the street side twin bed and rear storage compartments and drawer; the curb side twin bed storage compartment contains a 175+# Onan genset; additionally when enroute my spare tire lays on the floor between the twin beds since the genset fuel tank is mounted in the spare tire hanger.

My rear end may fall off tomorrow, but as of now there has been no harm.

[Inland RV Center, In]

Originally Posted by withidl

For what it's worth, adding weight to the rear of my 2002 ASCL 31' hasn't affected the structure after 35,000+ miles where I have at times found drawers open and occasionally on the floor from hitting highway irregularities.

I load my tools, bottle jack, cables, hoses, etc. in the street side twin bed and rear storage compartments and drawer; the curb side twin bed storage compartment contains a 175+# Onan genset; additionally when enroute my spare tire lays on the floor between the twin beds since the genset fuel tank is mounted in the spare tire hanger.

My rear end may fall off tomorrow, but as of now there has been no harm.

There are other issues involved.

1. Airstream "WILL" void your warranty.

2. An insurance company will deny any claim, because the damaged would be classified as "not being sudden, accidental, and direct".

3. All owners are certainly free to modifiy anything they wish, and at any time they wish. But, when it back fires, it's always someone else's fault.

It's always far better to be aware, as opposed to a surprise.

Andy

[Wild-Air]

Well, thankfully, the design of this dreaded solution includes a simple disconnect from the two 2" receivers. I'd hate to have Airstream void the warranty just to have some storage capacity, and I get the idea someone may just initiate that effort.

It's sad, too, not just because this solution cost a lot of money, but because it addressed a miserable void in a $70,000 travel trailer's utility: storage for camping gear.

And instead of some of the group's best informed trying to solve the problem, they chose to defeat it.

Rather than using creative juices to improve the breed, like what I did, some have only admonitions - no solutions - just gloom over messing with Airstream's rules. Sad.

[Wild-Air]

Originally Posted by perryg114

You did a very good job on the box.

Perry

That's a nice compliment - thanks! It seems the idea may need to be shelved until the warranty expires. But if I get a nasty letter from Mother Ship AS saying their end of the deal is over due to my idea being captured on these pages, I'll slap it right back on after properly reinforcing the frame. For now, it'll sit on the ground until the dust settles.

[Inland RV Center, In]

Originally Posted by Wild-Air

That's a nice compliment - thanks! It seems the idea may need to be shelved until the warranty expires. But if I get a nasty letter from Mother Ship AS saying their end of the deal is over due to my idea being captured on these pages, I'll slap it right back on after properly reinforcing the frame. For now, it'll sit on the ground until the dust settles.

I personally agree with your feelings, but being informed is always better that being caught off guard.

Andy

[daveswenson]

I think the key is reinforcing the frame. With all the talk of tail droop on here I'm nervous just filling up the rear storage that I have. I'd also be concerned about decreasing the tongue weight too much. If those issues can be solved I think your trunk is brilliant.