315RLTS: 265lbs Overweight!

[Second Chance]

Wow--that third pic really tells the tale. No hangers, indeed! (I hoped I marked the right spot on the pics. I can only guess this is $$$.)

The arrows just point to weld points. The beam above your arrows is a fabricated sub-frame on which the MOR/ryde units are mounted. The lighter colored, larger beam above the newly-painted sub-frame is the original frame rail (where the original hangers were fastened). There are no remnants of the OEM suspension system.

Rob

[BigGuy82]

Howard,

Not trying to be critical here at all, but it does look like you are sagging in the ****** end. Can you adjust the load distribution hitch or have you considered air bags. My guess is that your headlights are somewhat high.

[WhittleBurner]

Gary,

Before and after weights for our 7K x2 IS setup indicate the conversion added about 350 lbs. to the total weight of the trailer. However, this is weight that's part of the suspension system rather than weight carried on the chassis, so it does not add to the "cargo" the trailer chassis is carrying. In addition, our two 7K units increased capacity by 2,000 lbs. over the two 6K solid axles that came on the trailer.

Rob

Thank you Second Chance. What it would do though is add to the GVWR. We are thinking of upgrading and that is one thing we are considering having done. With the specs the trailer is showing it would not be a problem.

[Second Chance]

... What it would do though is add to the GVWR.

I was very careful not to say that - nothing can legally change the GVWR on the manufacturer's sticker. I would not want to increase the load on the Lippert frame that's under the rig. I simply subtract the 350 extra pounds from scaled weights before I "worry" about the actual weights vs. the manufacturer's GVWR. If @Cate&Rob were to see this and pitch in, I think he would support this position.

Rob

[SouthTX]

I was very careful not to say that - nothing can legally change the GVWR on the manufacturer's sticker. I would not want to increase the load on the Lippert frame that's under the rig. I simply subtract the 350 extra pounds from scaled weights before I "worry" about the actual weights vs. the manufacturer's GVWR. If @Cate&Rob were to see this and pitch in, I think he would support this position.

Rob

Rob - are you implying that GVWR is a "paper" limit and the earth won't explode if it is exceeded? [g]

[Cate&Rob]

I was very careful not to say that - nothing can legally change the GVWR on the manufacturer's sticker. I would not want to increase the load on the Lippert frame that's under the rig. I simply subtract the 350 extra pounds from scaled weights before I "worry" about the actual weights vs. the manufacturer's GVWR. If @Cate&Rob were to see this and pitch in, I think he would support this position.

Rob

Hi SC Rob . . . I don’t know how I got dragged into this (LOL ) but you are absolutely right that (just like a truck) nothing can change the GVWR assigned to a trailer by the manufacturer. But, you make a good observation that we don’t often consider . . . there is “sprung” and “unsprung” weight in any vehicle or trailer. Adding to the unsprung weight adds to GVW but does not add to weight carried by the trailer structure/frame.

Rob

[howson]

Howard,

Not trying to be critical here at all, but it does look like you are sagging in the ****** end. Can you adjust the load distribution hitch or have you considered air bags. My guess is that your headlights are somewhat high.

No problem--I appreciate your insights. Your input is always welcome.

I've got the Blue Ox set at 10 links. It is very difficult getting it locked with that many links so that's it.

I agree there appears to be a difference between the front and rear. According to Jim's spreadsheet the ratio of steer to drive axle is 42% so there's definitely room for improvement.

A better way is to measure the tire/fender gaps but I failed to do that prior to loading up. Once I get to our destination and fully unload I'll compare to what I have now. (Gotta remember to take measurements!)

Bags are definitely under consideration.

[Second Chance]

Rob - are you implying that GVWR is a "paper" limit and the earth won't explode if it is exceeded? [g]

John,

In my view, it's a bit more complicated than that. While with motor vehicles such as trucks, many things come into play such as registration classes and costs, etc. (witness the fact that most manufacturers offer GVWR "options" that only effect the sticker - not the equipment), I believe that towable RVs are a different matter. Design engineers specify components - everything from chassis rail/beam size to axles, hubs, bearings and springs - to a particular GVWR point. For liability reasons, margins of safety are built in. Therefore, no, the world won't explode if that number is exceeded by a reasonable amount under normal circumstances. Long-term exposure to overloading combined with shocks and G-forces outside expected parameters will likely, over time, result in a failure somewhere. Case study: the owner of a well-known RV-related web site and businesses knew he was overweight on his large, Lippert-framed fifth wheel and ran that way for a number of years... all the while relying on the design safety margin and his best-guess thought processes. The end result? A forward frame failure that allowed the pin box to collapse up into the trailer. Major surgery was required to repair and reinforce the forward frame and pin box support area and put everything else back together around it.

That said, I'm not an engineer (I haven't even played one on TV). I'm confident that the MOR/ryde suspension, Sailun load range G tires, and Demco pin box are capable of loads considerably above what's on the RV sticker. I just know that I'm not comfortable putting more on the Lippert frame than the design engineers say it is capable of. I stay away from arguments on the legal and insurance aspects of weight ratings...

The above was not paid for by any committee and is personal opinion, only.

Rob

[jim1521]

Howard,

Not trying to be critical here at all, but it does look like you are sagging in the ****** end.

Yeah, and you're trailer's ridin' a little low in the back too!

[SouthTX]

John,

In my view, it's a bit more complicated than that. While with motor vehicles such as trucks, many things come into play such as registration classes and costs, etc. (witness the fact that most manufacturers offer GVWR "options" that only effect the sticker - not the equipment), I believe that towable RVs are a different matter. Design engineers specify components - everything from chassis rail/beam size to axles, hubs, bearings and springs - to a particular GVWR point. For liability reasons, margins of safety are built in. Therefore, no, the world won't explode if that number is exceeded by a reasonable amount under normal circumstances. Long-term exposure to overloading combined with shocks and G-forces outside expected parameters will likely, over time, result in a failure somewhere. Case study: the owner of a well-known RV-related web site and businesses knew he was overweight on his large, Lippert-framed fifth wheel and ran that way for a number of years... all the while relying on the design safety margin and his best-guess thought processes. The end result? A forward frame failure that allowed the pin box to collapse up into the trailer. Major surgery was required to repair and reinforce the forward frame and pin box support area and put everything else back together around it.

That said, I'm not an engineer (I haven't even played one on TV). I'm confident that the MOR/ryde suspension, Sailun load range G tires, and Demco pin box are capable of loads considerably above what's on the RV sticker. I just know that I'm not comfortable putting more on the Lippert frame than the design engineers say it is capable of. I stay away from arguments on the legal and insurance aspects of weight ratings...

The above was not paid for by any committee and is personal opinion, only.

Rob

Rob - I should apologize, I wasn't digging at you, my comment was made tongue in cheek. I've argued the same thing so many times that I thought you knew where I stood on the issue.

You're absolutely right, it is more complicated than it needs to be. I'm used to dealing with aircraft where there are two kinds of rules - those made by the FAA and those by God. God's laws of aerodynamics are non-negociable. The FAA's rules may be exceeded in some instances. For instance, the FAA says an aircraft can't fly above a certain weight, I know that under some circumstances they fly very well at a much greater weight.

GVWR is a rule made by man. I may exceed GVWR and, in general, the penalty is paperwork of some sort. If I exceed God's rules (design engineers think they are), I run a very real risk of something more severe than just paperwork.

This is just a long winded way of saying that I observe GVWR to the extent that I don't have to upgrade my drivers license. OTOH, I have no reservations about exceeding GVWR up to the limit of my RGAWR.

Again, sorry for the cute comment, but I think we're both saying the same thing.

Best,

John