Rossmonster F550 ER type vehicle

[Steve_382]

They quit making them about a year ago and announced a new camper on an AEV Ram 3500. So far it's still "under development" with no price set, but I'd guess it will be in the $500k range.

There seems to be several of these type vehicles under development. Not too many that you can actually buy so far though.

 

[vwhammer]

Are theses trucks at the limit with the weight? Seems like a F550 is not enough for all they install.

It is my understanding that the F550 was within 2000 pounds of its GVWR.
However, it does have like 120 gallons of water on board as well as a washing machine, wood burning stove and an oven
Those last couple of things don't add a ton of weight but with all the things that went into this build out it adds up.
If you'll note, it seems the big green F550 was built using the standard build out foam core fiberglass panels.
These are usually pretty heavy as, in some instances, you have a fiberglass layer on the inside and the outside that can be 6-8mm thick. Then 25-50mm of foam. Then it's all held together with pretty beefy aluminum extrusions and most usually have a steel frame underneath.

Rossmonster does not use this type of construction and their boxes are much lighter.
There is no actual weight yet for the Ram 5500 but my guess is there should be somewhere between 4 and 5 thousand pounds left over before you hit the GVWR.

 

[charlieaarons]

It is my understanding that the F550 was within 2000 pounds of its GVWR.
However, it does have like 120 gallons of water on board as well as a washing machine, wood burning stove and an oven
Those last couple of things don't add a ton of weight but with all the things that went into this build out it adds up.
If you'll note, it seems the big green F550 was built using the standard build out foam core fiberglass panels.
These are usually pretty heavy as, in some instances, you have a fiberglass layer on the inside and the outside that can be 6-8mm thick. Then 25-50mm of foam. Then it's all held together with pretty beefy aluminum extrusions and most usually have a steel frame underneath.

Rossmonster does not use this type of construction and their boxes are much lighter.
There is no actual weight yet for the Ram 5500 but my guess is there should be somewhere between 4 and 5 thousand pounds left over before you hit the GVWR.

Did you say wood burning stove?
Is there a picture or description somewhere? What about the necessary height of stack?

 

[Steve_382]

Did you say wood burning stove?
Is there a picture or description somewhere? What about the necessary height of stack?

From this video:

 

[rruff]

If you'll note, it seems the big green F550 was built using the standard build out foam core fiberglass panels.
These are usually pretty heavy as, in some instances, you have a fiberglass layer on the inside and the outside that can be 6-8mm thick. Then 25-50mm of foam. Then it's all held together with pretty beefy aluminum extrusions and most usually have a steel frame underneath.

Fiberglass skins are much thinner than that! The whole panel is usually in the 1.5-2.0 lb/sq ft range. Edge and corner reinforcements, floor, and mounting points will add some weight, but if that's "a lot" they are doing it wrong.

The Rossmonster Baja's molded shell appears to be a single wall with an interior that is bonded to it, similar to a Bigfoot or Nothernlite. It would be inherently heavier for similar strength and stiffness, but the molded shell is prettier and more aero.

It's all the "stuff" that makes them heavy. The Earthroamers are actually over GVWR, but they recertify them themselves.

 

[rruff]

There seems to be several of these type vehicles under development. Not too many that you can actually buy so far though.

The anomaly of the past few years is settling down. There will be a handful of companies left that are actually competing... no more inflated prices and 2 year backlogs. This could be a particularly bad time to make a big investment in a new product, as many barely used rigs are being put on the market.

If Truckhouse had started with the AEV Ram platform I think they would have been better established, and more likely to make a go of it. For a new company, Rossmonster seems to have a good product and good reviews with the Baja. A lot depends on how they've managed the business end.

 

[rruff]

Another one joins the club. No idea whether this will be a real project, but here is a short video.

A quibble... if they are building this as one unit, why the huge gap between the sleeping berth and cab? Looks like at least 6". Headroom is always tight in the berth...

Maybe just a prototype issue that will be easily rectified in production.

 

[Steve_382]

The anomaly of the past few years is settling down. There will be a handful of companies left that are actually competing... no more inflated prices and 2 year backlogs. This could be a particularly bad time to make a big investment in a new product, as many barely used rigs are being put on the market.

If Truckhouse had started with the AEV Ram platform I think they would have been better established, and more likely to make a go of it. For a new company, Rossmonster seems to have a good product and good reviews with the Baja. A lot depends on how they've managed the business end.

If Truckhouse had started with a F350 I might be driving one right now. But, no, no, no....

 

[charlieaarons]

A quibble... if they are building this as one unit, why the huge gap between the sleeping berth and cab? Looks like at least 6". Headroom is always tight in the berth...

Maybe just a prototype issue that will be easily rectified in production.

Why? Have you ever seen how much the cab vs rear mounted structure (bed in a pickup or in this case camper body) twist on rough terrain?
That’s why there’s a 6” gap.

 

[rruff]

Why? Have you ever seen how much the cab vs rear mounted structure (bed in a pickup or in this case camper body) twist on rough terrain?
That’s why there’s a 6” gap.

Yes, I have that myself, but that is nearly all a roll motion. Even if you have the bed fixed in the rear and pivoting in the front, frame twist will not result in much vertical motion between the cab and camper. If the bed is fixed in the front, there won't be much relative motion in roll either.

An extreme case:

 

[vwhammer]

Fiberglass skins are much thinner than that! The whole panel is usually in the 1.5-2.0 lb/sq ft range. Edge and corner reinforcements, floor, and mounting points will add some weight, but if that's "a lot" they are doing it wrong.

The Rossmonster Baja's molded shell appears to be a single wall with an interior that is bonded to it, similar to a Bigfoot or Nothernlite. It would be inherently heavier for similar strength and stiffness, but the molded shell is prettier and more aero.

It's all the "stuff" that makes them heavy. The Earthroamers are actually over GVWR, but they recertify them themselves.

Apparently, Globe Trekker is making the skins on their panels much thicker because they were
definitely at least 6mm thick if not more.
I should also point out that they claim their panels are 2-1/2 inches thick vs 2 inches normally used.

It is also my understanding that Rossmonster uses a pretty thick fiberglass shell but then uses an aluminum frame inside of that that is bonded to the shell.
It is then insulated with various insulation types.

The claim there is that it is substantially lighter than the traditional foam core builds with extrusions holding it together.

Lastly, if you look at the link below you will see how substantial the "zero torsion Subframes" are for Globe Trekker's builds.
https://www.rvglobetrekker.com/all-sub-frames-components
I will guess that that is at least 3/16 thick steel and must weigh a ton.

Even if it was 1/8 wall thickness it would still be pretty substantial.

 

[rruff]

Globe Trekker is indeed making the Rossmonster shell, so that is pertinent info! They have a ton of videos on their site. I'm kinda put-off by GT because some of their promotional info is BS which doesn't give me a warm feeling, but they do provide a lot of good info as well, and many build videos. https://www.rvglobetrekker.com/

Globe Trekker INC

We are an Overland Expedition engineering solutions company, producing the best materials and engineered solutions for your next build. Our website: https://www.rvGlobeTrekker.com contact us: info@rvGlobeTrekker.com Facebook: https://www.facebook.com/RVGlobeTrekker Instagram...

www.youtube.com

Their walls are 2.7mm Azdel (2 layers for the floor) with a thin FRP skin glued on that is typical in mass RV construction. The Azdel is a luan substitute and it's very light, only 0.20 lb/sq ft per their spec page; must be foamed plastic with FG fibers? The core foam is polyiso, of uncertain density. The aluminum extrusions do look very beefy, and their brushguards are super thick.


I don't think the subframe looks that heavy; not compared to a typical flat bed.


Surely they'd tell you what the weights are if you asked, but I didn't see any on their site.

 

[vwhammer]

Indeed GT did make the box on the F550 that started this conversation and is seen on GT's website but the new boxes that could go on the 550 and 5500 platforms are Rossmonster's design with the fiberglass shell and aluminum internal frame.

 

[rruff]

Are they shown anywhere?

 

[vwhammer]

Are they shown anywhere?

Like are the shells shown anywhere or the whole, new, bigger baja?