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

[richxd87]

I'm doing something similar, building an 8ft flatbed on to a 6.4ft Ram 2500 for an 8ft Hallmark slide-in pop-up camper.



Question for @IdaSHO @locrwln @Alloy and anyone else who might have experience. Any thoughts on using these Energy Suspension universal body mounts between the frame and flatbed? I'm thinking it would help isolate some of the stresses from the frame.





OP, sorry for the hijack, hope you don't mind.

 

[rruff]

Any thoughts on using these Energy Suspension universal body mounts between the frame and flatbed? I'm thinking it would help isolate some of the stresses from the frame.

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That's what I'm planning to do on mine. My truck has 8 bed mounts. Haven't decided if the front 4 will be rigid mounted or I'll use the bushings like you did, but on the back I'll have two rails connecting the mounts on the frame, and each one will have two bushings in the center right next to each other that connect to the camper. Should have minimal tilt resistance in the rear. Unfortunately I haven't had any luck finding important data on these mounts like spring rate and load capacity.

Your need to accommodate frame twist will depend on your truck and camper. I think your truck is pretty stiff if it's boxed all the way, but you should test it by getting it crossed up as much as possible and measure it.

 

[Luckychase5]

I'm doing something similar, building an 8ft flatbed on to a 6.4ft Ram 2500 for an 8ft Hallmark slide-in pop-up camper.

View attachment 570346

Question for @IdaSHO @locrwln @Alloy and anyone else who might have experience. Any thoughts on using these Energy Suspension universal body mounts between the frame and flatbed? I'm thinking it would help isolate some of the stresses from the frame.

View attachment 570347View attachment 570348
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OP, sorry for the hijack, hope you don't mind.

All good! I love all the different content this is getting. It’s just giving me more ideas.


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[IdaSHO]

Richard, Im not familiar with the chassis on that vintage Dodge.

The mounts you have posted should do fine, but if there is substantial chassis flex and you intend to haul a (delicate) camper,
Id suggest something with more give, or a legit torsion free mounted bed.

The open C-channel frame on the Superduty is strong, but flexes.
So my build involves a 3-point pivoting subrame that is incorporated into the custom bed.

This allows the chassis to flex as it will, while the bed remains flat.

 

[locrwln]

Mine just has some kind of heavy rubber material between the frame rails and the flatbed rails that Alum-Line supplied. Then there are four u-bolts that hold the bed to the frame. I have twisted and flexed the crap out of mine and everything is doing fine. I just crawled under it a couple of days ago to double check everything. The bed is still great and I maybe got a quarter turn on the u-bolt nuts, so I figure that's not bad after 30k + of use. And that's with doing stuff like this:

Your idea of using the suspension bushings is solid and it what I had planned when I was going to build my chassis built camper.

Jack

 

[Darwin]

I went with a captive spring mount for my flatbed, for similar reasons IdaSho mentioned, but my ram is a cab and chassis so it has a different frame design than the standard pick ups, so it might not be necessary? Something to consider though.

 

[rruff]

Mine just has some kind of heavy rubber material between the frame rails and the flatbed rails that Alum-Line supplied. Then there are four u-bolts that hold the bed to the frame. I have twisted and flexed the crap out of mine and everything is doing fine.

If you have a photo of how that goes together, I'd appreciate it.

 

[richxd87]

Thanks for the input fellas!?

Jeep tested it out on a 2004 and didn't seem to think the frame would flex too much so I'm gonna go with his findings. Link below
Flatbed and composite panel build

I'm going with 6 of these mounts in the factory bed mount locations, 4 in the rear and 2 in the front. The rest of the crossmembers will sit on poly bushings also but not bolted.

 

[Luckychase5]

Well, it sold before I could go to the bank tomorrow. I’m super bummed... thanks everyone for their input. Cheers


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[locrwln]

If you have a photo of how that goes together, I'd appreciate it.

Here you go. These were about as good as I could get.

I know that the angles are off from me lying under the truck, but hopefully you understand how it’s put together.

Jack

 

[rruff]

Thanks a bunch! Doesn't look like much "cushion" at all, and it appears that the Ubolt is denting your frame in the 2nd photo... is that right? Is the camper hard mounted to the flatbed, or is there accommodation for some give there? I think the frame on your truck is designed to torsionally flex quite a bit. Whatever it is it obviously works!

 

[Alloy]

Thanks a bunch! Doesn't look like much "cushion" at all, and it appears that the Ubolt is denting your frame in the 2nd photo... is that right? Is the camper hard mounted to the flatbed, or is there accommodation for some give there? I think the frame on your truck is designed to torsionally flex quite a bit. Whatever it is it obviously works!

I've seen U-bolts kink the flanges of a few frames. True square bent (zero radii) U-bolts are difficult to find and the frame should have blocking or trip brackets inside the channel. If you can find the Body Builder Guide for the truck it will provide some detail as to how to fasten to the frame.

Ram Commercial Body Builder Guide - Upfit Your Truck

Ram Trucks Body Builder's Guide has information you need to upfit your truck. Explore the Body Builder Guide for dimensions, electrical & technical guides.

www.ramtrucks.com

Publications | Body Builder Advisory Service

.

 

[Simons]

Example of an “unbendable” domestic super frame!

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

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[locrwln]

Thanks a bunch! Doesn't look like much "cushion" at all, and it appears that the Ubolt is denting your frame in the 2nd photo... is that right? Is the camper hard mounted to the flatbed, or is there accommodation for some give there? I think the frame on your truck is designed to torsionally flex quite a bit. Whatever it is it obviously works!

No problem. I think it’s just an illusion from the angle and there might be a paint scuff next to the u-bolt. Yes, it’s bolted to the flatbed at the four corners. I’ve tested it before and there isn’t much flex even though it’s a c-channel frame at the rear portion.
Here it is with the original bed and my FWC. The rear tire is hanging in the air and there is less than an inch of deflection between the cab and bed. I had the truck pretty twisted here and that’s as bad as it gets.

Jack

 

[Regcabguy]

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.