Would you believe?

[startrekker2001]

I just got back from the Florida State Rally where I learned a few things. One of them was that since 2000 the law requires trailer manufacturers to placard the trailer with the Cargo Carrying Capacity (CCC).

Here is one from a 2005 34' Classic that might surprize you. Note that this $90,000+ trailer is overloaded if you load 445 pounds of cargo. The rule of thumb for cargo carrying is 2000 for non fulltiming and 3000 pounds for fulltiming. What is the point of having a trailer you can't safely use?

I asked the Airstream Rep why and his response was that people want more and more goodies like Corian Countertops, slide outs, natural wood... etc. The frame can hold only so much and the goodies' weight has to come from somewhere and it comes off the CCC. I looked at the same model without the slideout and it had a CCC of 1150 pounds. The difference was the weight of the slideout. It was pointed out that there hasn't been a failure due to overloading but that seems a weak arguement considering the emphasis on safety. I wonder if they point out the CCC to prospective customers? To be fair, the 25' had a CCC of over 2500 pounds, so there are many that meet or exceed the needs of the buyer, but HOLY COW!!!

[Pick]

Guess you'll need one heck of a tow vehicle, so you can keep your "stuff" in it.

When we go Airstreaming, we usually just have clothes and food in the coach. Grill, charcoal, bikes, porch mat, all stay in the truck when we are in motion.

[Silvertwinkie]

Slide out units weigh more than non slides, so a lower CCC would be expected in a slide than a non slide). That said, it's been my understanding that Airstream has increased the axle capacities on the coaches across the board. I would guess that any coach made *around* 1/2005 would have the upgraded axles which would increase the CCC. If your unit is not one of those units, to me, your CCC would make sense (not that I agree with the limit). However, if your unit is one of those units that has the upgraded axles then YIKES!

[Coastalview]

Interesting info. I guess for most purchasers, a suitable tug + storage would be a priorty.Sure would hate to void a warranty, with a few goodies you may pack in a closet somewhere.

[Chuck]

I've been wondering where they come up with these numbers for campers...and tow vehicles, as well, for that matter.

with airplanes, the "gross weight" is basically how much the aircraft can weigh, and still fly. ok, well...its more complicated than that, but that is the basic idea. exceed this weight, and it won't fly any more. "thrust + lift-weight-drag= >0", and you're in business. we have charts and graphs and formulas to adjust for varying atmospheric conditions. The point is that the number is based on something "real".

so what happens if you put more than 445 lbs of stuff in it? (minus the assumed safety factor that the factory adds in) does the frame snap in half? or what?

same for trucks: we know not to exceed the gcwr. but why? what happens if you do? where does the factory come up with this number? seems that historically, half-ton pickups have had gcwr's around 12k-ish lbs...with a 7k-ish lbs tow capacity. in the last few years, they suddenly seem to all have 9k tow capacities, and their gcwr's have jumped to 14k-ish. my question is: did they actually *do* something to the trucks to arrive at this higher gcwr, and subsequent tow rating, or did they just arbitrarily jack up this number?

we've all seen the Dodge Intrepid pulling the 34 footer. (not to start that debate again...). its obviously overloaded by any measure. but it can pull it. whereas, if I attached a 34 foot airstream to the back of my piper cherokee, it would never leave the ground.

[Porky Pig]

Originally Posted by chuck

whereas, if I attached a 34 foot airstream to the back of my piper cherokee, it would never leave the ground.

And there's the rub ... why can't we do this? After all these years, why hasn't Airstream fixed this design flaw?

[DreamStream]

Just noticed the NCC for the 34 S/O is listed as "TBD" on the Airstream.COM website. So I can haul more stuff in the Bambi ... interesting.

[rluhr]

The limit on the 34 SO is probably driven by the axles. Three of Henschen's 3500 lb axles = 10,500 lbs. That's exactly the GVWR of the 34SO. I doubt it is a coincidence.

If I had to guess -- and this is not based on any inside information -- the GVWR of the 34SO will increase as soon as Henschen has an axle available with a higher rating.

I suspect that the units on the road today (which are probably ALL overloaded, given the amount of storage in a 34 footer) are overloading the axles. What happens when you overload new axles? Higher rate of breakage? Bottoming out? Tire blow-outs? It can't be good.

[thenewkid64]

I can see a few other issues.

Most tires that are available today have a max load of 3600 LBS, same for the wheels that are bolted to that axle. At least in a 15 inch size.

Unless there is a way to make the tire and wheel deal with the additional load, stronger axles will not make much of a difference. Some of the new 5th wheels that are out there are now going to a 4 tires mounted as duals setup to be able to carry additional weight that they are building.

[Silvertwinkie]

I agree, I belive it was the axles and that is why an upgrade (from what I have heard) has been done. I'd be interested in seeing what the new axle ratings are currently at. In this particular case, I'd be interested in hearing the date of manufacture. If it's prior to later end of 1/2005, then it would be the old axles and as such shouldn't have a higher rating...which could account for the TBD on the Airstream website-- they have yet to update since the new axles have been installed. I know the new Safari SS (25') now has a 7300lbs GVWR up from it's 6300lb GVWR which did change last month.

As for tires, our Safari has Marathons rated at 2680lbs each. I know Airstream had these same tires on the 30' Slide because I recall Jack telling me so. If that is the case, 2680lbs x 6 wheels would enable a coach upward of 16,000lbs. In a tri-axle setup, depending on how the coach was loaded I would think this more than up to the task of say an 11k coach. On a dual axle coach, say the 30' slide, I could see one getting very close to the limits of the Marathons load ratings and in some cases, depending on what cargo was placed into it, even exceeding the tires rated limits.

The problem from what I can tell is clearly the axles, which I think might have very recently been addressed.

One question that comes to mind would be with an extra 1000lbs of weight availible, will the coach travel more roughly with a more stout axle if you don't load it close to the 7300 (on the Safari for example)? In the case of this Classic, you'd think it was a no brainer, but it's not as clear on some of the other models.

[Porky Pig]

Originally Posted by rluhr

I suspect that the units on the road today (which are probably ALL overloaded, given the amount of storage in a 34 footer) are overloading the axles.

Not ALL. I'm a nutcase when it comes to weight. Since being on the road for a year ... I have taken Baby Huey to the CAT scales twice ... both times within spec.

It drives Petunia crazy when we're out shopping ... I always ask ... how much does that weigh?

If my memory is correct ... Airstream upped the weight limit on the axles for the 34 either in 2002 or 2003. I remember when this happened ... it was during the time I was starting to shop for one ... and was pleased when the change came along.

I better not let Petunia know about the new 2005 axles.

[rluhr]

Originally Posted by Silvertwinkie

... 2680lbs x 6 wheels would enable a coach upward of 16,000lbs.

Now I'm wondering .. is the 2680 lb rating is per tire? In other words, is the tire weight max. for a single axle (with two tires) 5360 lbs, or is it 2680 per pair of tires?

What about the wheels? Same deal?

[Silvertwinkie]

According to my tire it can take 2680@65psi-- each tire, single, not dually the way I read it. Now I doubt the one axle on my Safari can hold 5360. Most likely my year can only hold *about* 3150 each axle, which is a whole different beast on the tri-axles, but it gets you in the direction I'm headin'.

My whole point is that if the factory in fact did put the next model up on the trailers, each new axle on the Safari would hold *about* 3650lbs-- well within what all 4 tires could hold combined which is *about* 10,700lbs.

I could be wrong, but take a look around and let me know. As far as I know, I'll overload the axles on our Safari before I overload the tires. Safaris made late in 1/05 will have more NCC as a result and should not overload the axles or the tires at 7300lbs GVWR, of course your specs will usually vary compared to a 25' Safari SS.

[wahoonc]

There was a looooong post about this very subject on RV.net a while back, a couple other items that come into play from the engineering standpoint too, is the tongue weight, and the unsprung weight. The weight of the tires and wheels may or may not be included in the calculations (quite often not)...BTW my Vintage has a CCC of about 1800#. The owner's manual(s) have very specific weights and listings to help figure out where you are going to end up. For example Vista Views will add 64# to the axle weight and 8# to the tongue weight....must be new math....

Aaron

[baldeagle]

2002 Classic 31W - Street side bath, queen.

Trailer Weight Information Sticker
GVWR 8,700
UVW 7,199
60 Gal Water 504
LPG 13.3 Gal 60
CCC = 937

Hope this helps some

Dave

[overlander63]

Originally Posted by rluhr

If I had to guess -- and this is not based on any inside information -- the GVWR of the 34SO will increase as soon as Henschen has an axle available with a higher rating. What happens when you overload new axles? Higher rate of breakage? Bottoming out? Tire blow-outs? It can't be good.

I have a 4500 pound axle on my Argosy, it came stock in 1972 with the same rated axle, so a lack of available axle capacity shouldn't be an issue.
As for the overloading, you can expect a higher rate of bearing failures, brakes wearing out prematurely, broken shock mounts, tire failures, etc. Also, you may have excessive frame flexing, resulting in metal fatigue and broken frame members. You may also have an increase in exterior leaks, as the frame flexing will stress joints and seals in the skin of the trailer.
Also, the effects of overloading are cumulative. If you overload your trailer today, you may get away with it for a while, but you will be reducing the years and miles of usable life from your trailer.

[Minnie's Mate]

One thing to remember when doing the math with a slide...the weight of the slide is mostly on the street side and little on the curb side. So the weight distribution will affect the wight limits of the capacity of the tires and wheels, i.e. if the capacity of the tire is 3600#, the 10,800# max load capacity of the three tires on the street side will be affected more by the weight of the slide than the 10,800# capacity of the curb side tires because of the uneven weight distribution. Since I am not that familiar with the layout of the 34' slide, I don't know where the cargo would be stowed, but I would assume Airstream placed most of the storage on the curbside to compensate.