Forum Discussion
coolbikeman1
Aug 05, 2015Explorer
MM49 wrote:69 Avion wrote:
This is a fabulous discussion. Bt the way, I'm not the one that said you shouldn't tow an Airstream with a heavy duty pickup, an Airstream expert did. He also stated that too heavy of WDH bars will harm the Airstream trailer.
Here is the quote, "Early frame failures are usually due to grossly out of balance running gear, or, towing with a super heavy duty tow vehicle and an excessively rated hitch bars, or a combination of those."
This particular discussion came about when I mentioned frame issues. I was called out to prove it. So I did with plenty of examples.
Another example:
http://www.airforums.com/forums/f36/frame-failure-22-foot-international-48105.htm
It is nice to finally see someone admit that there were problems with certain models. The above example is a 22' model that was only 6 years old at the time of discovering the failure. The engineering didn't change on this model except for weight distribution with the layout of the traier. Think about it for a moment, (without the emotions) this trailer is a tandem axle that is only 22' long. The frame design is basically the same as most of the others, except shorter. Longer frames with more overhang will have more stress, especially if the shell is seperated from the frame. The issue is that the frame problems aren't just on the 22' models.
I must yield to folks here with more experience than me. I've only been building equipment trailers, on and off, for over 40 years. I have experience with many trailers, but I must admit, all the trailers I build had to support themselves. Understanding the semi-monocoque system, any serious failure in the connection between the frame and shell WILL cause an eventual frame failure.
Now to the axles that were mentioned above. Some folks really like the rubber torsion axles. I have used many of them over the years. They are great for a few reasons. One, they are independent. Two, they actually help support the structure as they become part of the structure. Three, they give a good ride. Four, they are cheaper to install since you don't have to deal with all the shackle brakets. If Airstream used the FlexiRide type, you could actually change the torsion angle by removing one bolt from the splines.
Now for the negative. The rubber hardens in about 20 years or so depending on the temperature. The axles don't have an "equalizer" so when you go over a large bump (usually over 6"+) the first axle will have all the weight of the trailer (that isn't on the tongue) on one axle, then the second axle. So, if you have an 8000# trailer with 1000# on the tongue, equipped with two 4000# axles, each 4000# rated axle will have 7000# on it as it goes over that sharp bump. Combine that with a marginal frame and guess what happens over time?
A leaf spring axle won't do that since it has an equalizer. There was a system that Dexter made with a split leaf spring axle that gave you an independent suspension and the equalizer, but it takes more time to build and a heavy frame to support the suspension. Another issue is some rubber torsion manufacturers will not recommend them for triple axle configurations because the lateral stress can pull the torsion arms out of the axle tube.
It might be a little unfair to blame a poorly designed torsion bar WDH hitch on optimized frame design. I for one think that the basic adjustment instructions for torsion bars are all wrong for today’s heavy duty trucks. You should only be transferring a portion of the TW weight forward. The HD trucks are F/R out of balance and they benefit from a substantial TW on the rear axle. The TW left after loading the rear truck suspension is the only amount that should be equalized. This would require much smaller torsion bars with less damage to trailer frames and suspensions.
There is not a chance that the public will ever understand this. I was at a large campground this week end and 9 out of 10 RV’s were set up incorrectly. The owners are in ignorant bliss and this will not change.
MM49
Like I said earlier, make an informed decision.
I am also interested in purchasing an Airstream in the future and really like the input from this topic. But, in the quote above about
" The TW left after loading the rear truck suspension is the only amount that should be equalized. This would require much smaller torsion bars with less damage to trailer frames and suspensions.
There is not a chance that the public will ever understand this. I was at a large campground this week end and 9 out of 10 RV’s were set up incorrectly. The owners are in ignorant bliss and this will not change.
MM49"
has me a little confused. Can you explain this a little more clearly? Is this the trailer tongue weight? And, how does this change by connecting the trailer to the truck suspension unless you engage the weight distribution part of the hitch? How do you know how much weight you are equalizing? I go by the wheel height measurements before and after adjusting the WDH. I currently have a Holiday Rambler travel trailer and can tell how much tongue weight is on my truck by going to weight scales and getting all axle weights and subtracting the actual unconnected weight of the truck from the axle weights when using the WDH.:?
About Travel Trailer Group
44,052 PostsLatest Activity: Oct 14, 2025