Long flatbed on a short bed truck? Head of it?

Regcabguy

Oil eater.
b920ca51f6def4194f715e1ace7cfc70.jpg


Example of an “unbendable” domestic super frame!

Guessing a 24’ extension on a 20’ van frame!

Sent from my iPad using Tapatalk
That's hilarious.
 

rruff

Explorer
My friend's got a Lance 825 on his '05 4 door shortbed Ram. The rear axle load is 2200# over the front. He's not happy with the handling saying it feels tail heavy. He's got Kings,a swaybar,airbags and E-rated 3600# tires on it. It's going to be sold and replaced with a longbed and a longbed model camper. It's the law of physics,nothing more.

The "law of physics" is that handling is going to suck with a big top heavy camper... granted he may do better with a long bed truck, but that isn't the only way to fix that problem.
 

primussucks

Member
Good thread.
I'm going through this decision myself.

06' Ram 2500 Quad Cab, 4x4, Short bed.

I'm looking at a camper that is 8' long. all the heavy stuff (water, batteries and cab-over) will all be between the axles. Basically the only thing behind the axles would be the box itself and anything hanging off the back of the camper (bikes and such).

I'm debating on an 'off the shelf' aluminum bed, or a customer frame. Either way, I think either way bushings or spring system will need to be employed to handle off camber stuff

We got pretty twisty on Chicken Corners this summer, but didn't seem to twist the frame too much (look at the body line between the cab and bed). So maybe direct mount would be ok?

IMG_3030.jpeg
 

IdaSHO

IDACAMPER
Pretty sure your '06 RAM has a fully boxed frame.
It should be stiff enough to avoid the need for a torsion free mount subframe.
 

rruff

Explorer
I'm debating on an 'off the shelf' aluminum bed, or a customer frame. Either way, I think either way bushings or spring system will need to be employed to handle off camber stuff
We got pretty twisty on Chicken Corners this summer, but didn't seem to twist the frame too much (look at the body line between the cab and bed). So maybe direct mount would be ok?

I agree; direct mount is good if you have a fully boxed frame. It's easy to check.
 

RAM5500 CAMPERTHING

OG Portal Member #183
Careful on the “fully boxed frame” logic.

Some trucks have what look like fully boxes frames, and they are, KINDA

My Tundra for one was “fully boxed” from about the front leaf spring perch back and it was C channel right where the cab and bed met. THAT is where it all flexed, and that frame flexes like crazy and would need a torsion free mount FOR SURE

not sure how the Rams are. But something to look at closely
 

IdaSHO

IDACAMPER
Don't confuse "boxed frame" with "fully boxed frame"

My superduty has a "boxed frame" from cab forward.
but is open C from cab back. It is not FULLY boxed.

2006 RAM has a fully boxed frame.

s-l1600.jpg


 

RAM5500 CAMPERTHING

OG Portal Member #183
Don't confuse "boxed frame" with "fully boxed frame"

My superduty has a "boxed frame" from cab forward.
but is open C from cab back. It is not FULLY boxed.

2006 RAM has a fully boxed frame.

s-l1600.jpg



Thats ************
 

rruff

Explorer
My Tundra for one was “fully boxed” from about the front leaf spring perch back and it was C channel right where the cab and bed met. THAT is where it all flexed, and that frame flexes like crazy and would need a torsion free mount FOR SURE

Didn't you tell me your Tundra flatbed+4WC was hard mounted? :unsure:

The only part of the Tundra frame that's boxed is under the engine. From there to the forward leaf mount it's reinforced C channel, and from that point back it transitions to much wimpier open C. It flexes a fair amount, but not as much as the Fords I've seen with open C frames. Teetering on 2 wheels I can get ~3" of flex from the front to back of my 8ft bed.

image-asset.png


Surprisingly everyone I know who puts a flatbed+camper on a Tundra hard mounts it. I guess that works fine if your flatbed+camper is stiff and strong enough to make a solid unit with the frame. But then you lose the "point" of the flexible frame which is to provide some articulation. You can remedy that to a degree with good rear leaf springs that articulate. That will make it sway more on the road... and then if you put a sway bar on to fix that problem, you've reduced articulation again. No free lunch.

These folks don't mention a pivot in their build, and it looks to be hard mounted. Even in that modest ditch, the flatbed+camper has shifted way out of line with the cab... and it is also a very solid unit with no twisting or distortion evident in the camper. Rather all the frame flex is occurring forward of the flatbed. Note the angle of the front bumper relative to the cab.

A7307165.jpg


I'm still dithering on what to do with mine. It won't be hard mounted (I don't have a stiff subframe), and a 3 point pivot would be safest for the camper, but I wonder if a middle ground with soft cab mounts would be best... like these for an older Superduty.

81WO9EsxWAL._AC_SY450_.jpg


I'd rather have a boxed frame honestly; mount the camper solidly, and deal with articulation via the suspension.
 
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IdaSHO

IDACAMPER
Biggest issue I have with hard mounting a box that is strong enough to stiffen a would-be flexible frame like that of a Tundra,
is that you potentially create a failure point in the frame itself, between the box section and the open C

IMO, you either let a chassis that is "designed" to flex, to flex
Or you have a rigid chassis.

So if you make any efforts to make a would-be flexible chassis stiffer, you'd better have the engineering to back it up.
Which is why my 3-point pivoting setup on a superduty is what it is. It allows the chassis to behave as engineered and designed.
Im not trying to reinvent the backbone of the truck. Instead, work around its natural behaviors.
 

rruff

Explorer
Biggest issue I have with hard mounting a box that is strong enough to stiffen a would-be flexible frame like that of a Tundra,
is that you potentially create a failure point in the frame itself, between the box section and the open C

The boxed part is a long ways away (under the engine). The transition point would be on the reinforced C part. I understand your point though. Seems like the frame and flatbed both would experience a stress concentration at the most forward attachment point.

The main reason I hesitate on just doing a 3 point, is the potential for excess camper sway on the road.
 

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