really the most important aspects of your new fifthwheel, yet most people don't even know the right questions to ask to find out whether or not they are getting a good product. Before purchasing a fifthwheel, especially one with a slide-out, you better find out about the construction of two major components:
1) The Chassis Frame
2) The Main Floor
If components are not up to snuff, long term slide-out fit and good towability are probably not in your future. That is why so many of our GS specifications have to do with these vital fifthwheel components. Lets take a look at them and see why each is so important.
The Frame
The main floor hanging after the main axle position is a cantilever structure, meaning it is being partly supported by the walls themselves (sort of the opposite of a house). If you have a fifthwheel with a slide-out, then you have a big rectangular hole in
 The gooseneck. |
Therefore it is important to design and build a fifthwheel with a floor that doesn't tend to flap up and down as you travel down the road.
To insure that the floor doesn't over-flex you have to start with the main chassis frame. Just like when building a home, if you have a good foundation then you can be confident that the walls will be true. Many of today's RV manufactures still use the same steel chassis frame for their slide-out models as they did for their earlier non-slideout models, which was often a 2" by 6" or 2" by 8" rectangular tube.
As long as you didn't cut a big hole in the side of the wall, this frame was fine, but with a major part of the wall section cut out for a slide-out room they are lacking a strong enough wall to hold the floor up. Remember we talked about the wall helping to support the floor? RV walls act as a large bridge girder and literally hold the floor up. If you cut a big hole in the wall for a slide-out, what is going to keep the floor from flexing up and down? The answer is that the floor and chassis have to take care of themselves. The manufacturers who have not correctly redesigned their chassis frame and floor for slide-outs have had many slide-out fit and gasketing problems. If you have shopped for fifthwheels and talked to owners of slide-outs not correctly re-designed, then you have undoubtedly heard several horror stories about non-fitting slide-outs that refused to slide either in or out, or if they did, didn't fit.
This is why our GS specification calls for a 10" Junior "I" beam frame with special gusseting at the "goose neck" transition from the main floor to the bedroom level. An "I" beam is the best available structure to not only handle
 The heat treated I-beam. |
A major part of our GS specification for the chassis calls for the frame to be heat treated. This treatment causes the frame to bow up like a big bow string. When we start with a frame that is bowed up about an inch we then effectively have a large spring on which to fasten our main floor. Once we add the weight of the floor and walls the frame flattens out, however there is always an upward springy force on the floor caused by the up-tensioned steel chassis frame. This attention to our GS specification for chassis frames is a key item that most retailers just don't want to pay extra for . . . . so they don't.
The Floor
While shopping for a new fifthwheel you really can't see what the main floor is made of and many manufacturers are hoping that you won't really care, or even know to ask. After all, aren't the most important things about a new fifthwheel whether or not it looks good, how big it is, and how much it will cost?
Our bathroom floor over the heated basement storage area is made the same way our walls are made. It is an aluminum frame sandwiched between laminated layers of plywood. As you most likely have noticed, most fifthwheel floors squeak in the bathroom. This is because they are constructed using Oriented Strand Board stapled to 2 inch by 3 inch joists. This type of floor is a little heavy, doesn't contribute to the structural integrity of the overall boxed structure, and tends to over-flex while being walked on. Our laminated, solid bath floor becomes an important part of our overall structure, is relatively light weight, doesn't squeak, and costs more to build than the floor used by most other manufacturers. This is just another example of a costly construction detail meeting our GS specification which is normally unseen.
Some products are good they day they where made and some aren't. As Ben Franklin said, "the quality remains long after the price is forgotten" On this page is a picture of two good products that have served me well over the years. One is my 1973 Volvo (my new car . . . I guess I get frugalness from my father) has over 300,000 miles, has it's original engine, every thing still
 The infamous cars. |
We hope our products will be as durable as these two (which is what the GS Spec. is all about), but without putting time and money into our fifthwheels in places that they won't show right away, they just wouldn't. Let me tell you a little story that illustrates why we make our floors the way we do, and why we think they are so important.
About a dozen years ago, because he knew we had a truck with a fifthwheel hitch in it, our banker called and asked us if we would pickup a finance repossession. This was an unusual request as fifthwheel finance repo's are basically unheard of. Never the less, we said we would pick it up the next time we went through Nevada. The fifthwheel we were to pickup was in the High Nevada desert at Pahrump, near Las Vegas. On the way back from a trip to Utah we stopped in Pahrump and hooked up to the 36 foot fifthwheel made by one to the 3 main public corporations who manufacture RVs. It wouldn't be nice for us to tell you the brand, so we won't. Because there were some personal belongings inside the coach, we didn't unlock the door. Besides, the lights, turn signals, and brakes worked, and that was all we really had to worry about.
When we brought the unit into the bank parking lot in San Diego, California, the banker came out with a key and we all took a look at the inside of the fifthwheel. We looked inside we where astonished to find that the main floor was missing. The refrigerator was hanging from the wall and the cabinets were in place, but when we looked down all we could see were axles, wires, and heat ducts, but no floor.
To make a long story a little shorter here is what happened. The roof vent was slightly open and either rain or snow had made the floor wet. It gets cold in the high desert at night and the temperature can go below freezing. Now if you freeze damp particle board it will return to it's original state . . . saw dust. We must have left a 350 mile trail of saw dust down the interstate.
That floor was no good the day it was installed. The pressures on purchasing agents in our industry are tremendous. If they can save a little here and a little there, they can produce a bigger product for fewer bucks.
Now the standard main floor installed in our industry is made from oriented strand board (OSB) or construction board. It is really far superior to particle board, however it is very flexible in the left to right direction. If you go down to your local building material store you will find that a 4' X 8' x 3/4" sheet of OSB costs about $9.70.
Our GS specification, however, is not for OSB but for tongue and groove plywood decking. The tongue & grove prevents squawks, and plywood is far less flexible than OSB. If you are shooting for a floor that can withstand flexing and moisture over the years, then plywood is a must. Have you purchased plywood recently? It's like solid gold. A 4' X 8' X 5/8" sheet of our plywood decking will cost about $32.50 per sheet down at your home supply store (about three times more than OSB). Now which material do you think the purchasing agent will choose when the shopper can't tell what the floor is made of anyway? You guessed it. Now you can see why our GS specification for the floor is so important and why the Nevada desert had a lot to do with that specification.
