Adding a rear seat to composite camper with shoulder harness intended for family to travel in in order to avoid a crew cab

S2DM

Adventurer
There are crash tested sofa bed seats all over Europe , plans on eBay , kits avaliable I think, crazy exspensive, considering something similar, our old motorhome had seat belts everywhere, not sure how to incorporate any roll over protection , but anything built today will far surpass that old motorhome. Never a fan of crew cabs

Yeah, I've seen those.
 

S2DM

Adventurer
I think questions like this give you a good cross-section of the expo community :)

I'm leaning toward sticking with a crew cab even though I think a cage a rear cage seat set up would actually be safer and stronger. If you look at the cab, there really isnt that much structures in the B pillars, and a ton of the strength is lost by adding a pass through, no way around it. In a cage type set up, you could engineer in crumple zone, and it would have a structure that a cab just couldn't really match. Obviously the cage would attach to the frame, the seats to the cage and the seatbelts to the cage separate from the frame.

Heres a quick render or the idea in SW.

Section View 1.JPG

Missing from this drawing are the seats themselves and seatbelts but you get the idea.

As I look at it more I'm leaning away for a few reasons. The big one being that in order to get the seats low enough to have a horizon view, you really lose room to put any systems below. It would function as a nice dinette seat either way, but I'm seeing fewer advantages to it as I look at it more. One way or another you have to have a spot for the kiddos, I wouldn't do it side facing, and I'd be very hesitant to do it in the back, so the advantages of a dual purpose space when the seats have to be low enough for people to see while underway start to diminish.

My current idea is to build a custom rear seat for the crew cab based on the reversible back architecture you used to see in railcars. Something like this, excuse the horrendous video.


Idea being when you pull into camp, you can reverse the whole back of the rear seat to a rear facing position. Some disadvantages as a dinette location, but could be a nice overflow sleeping spot, extra couch or a spot for the dogs to bed down etc. Obviously would have to sort out positive stops etc, but I think this might be the direction we head and begrudgingly stick with a crew cab :)

-S
 

Lwing

Member
If your thinking outside the box, I'll throw this out there, first I'll admit, I know very little other then the years of research I've been doing for my build, nothing appealed to me on this continent, bold statement. Where I've been and where I want to go in comfort, overall length and width is a big deal. Crew cabs won't work due to wasted space, neither will regular cab trucks as I'm too tall and not enough leg room. Anything 8' wide won't work either on a lot of the roads I travel. Had a 24' 4x4 motorhome, realized too long to wide, too poor quality, but it gave the family comfort. If only there was a quality 21' long 7'4"+- wide motorhome with an independent camper box and pass through, that would handle some abuse. Closest thing I've found is the Bimobil ex 358 and it needs better departure angles. It got the wheels turning, bought an E450 C&C diesel with 25 km on it, 4x4 conversion done with 35" Toyos m608z tires. Liked the idea of sprinter swivel seat ideas and considered it as an option with a rock and roll bed to form a dinette. This would of made the connection opening very large, but I believe doable. As my family is shrinking and my partner has almost zero interest in exploring with me, I will be going with a small pass through. For added leg room and cab interior I added a 12" cab back extension and moved seat back 4.5". I have considered a cage around rear of cab as it now enclosed with a Fiberglas shell and it doesn't offer much in protection, or maybe beef up front of composite camper to form a headache rack. A van offers a shorter overall length, sacrifices a bit of ride quality and maybe 4x4 ability, but once arb lockers added it will go where I need it to go. Box Manufaktur out of Germany makes the nicest composite cabover shells I've seen, and will try to emulate that style construction. You could go van route where front seats swivel to open reinforced pass through to composite camper on spring loaded sub frame, have some seats with shoulder straps that do duty as a dinette and a fold down bed? A little outside the box but ideas been done successfully for 40 years in motorhomes, just needs an engineers touch and some dragging, kicking and screaming into the expedition world. And no, nothing like a sprinter.
 

Buliwyf

Viking with a Hammer
If you waste the first few feet of the box, with a cage and seats, how is that better than a shorter box and a crew cab truck?
 

grizzlyj

Tea pot tester
Having just looked on ebay UK some of the cheaper ones don't explicitly say they are of the crash tested legal to fit type?
A few years ago any frame could be bolted down in the UK, once crash tested became required the price rocketed and the cheaper ones kind of disappeared for a bit. It's possible cheaper ones that don't say crash tested leave the legal responsibilty with the person fitting?

Two seats need a gap between to get through the crawl through, so may as well rotate?
 

S2DM

Adventurer
If you waste the first few feet of the box, with a cage and seats, how is that better than a shorter box and a crew cab truck?

That’s kinda what I was getting at with diminishing returns. In a tall cab forward design, I think you gain something because those rear seats could rotate and serve double duty as a dinette. In a 3500 with a lower cab and the frame elevation behind the cab, the seats basically have to be on the floor and it doesn’t buy you as much.


Sent from my iPhone using Tapatalk
 
Last edited:

Screwfly

Member
Like Lwing suggested, could a van chassis be a good compromise?
Could do a crew style cab but would still have overall shorter length.
 

S2DM

Adventurer
Like Lwing suggested, could a van chassis be a good compromise?
Could do a crew style cab but would still have overall shorter length.

Don’t want to step on anyone’s toes, but I’ve yet to see a van chassis cab with the requisite 6500 lb payload that’s truly capable off-road. And it would need to be a chassis cab style so I could make a box tall enough for me (6’7”).


Sent from my iPhone using Tapatalk
 

Lwing

Member
Realize it's not for everyone, or anyone other then myself, you wouldn't be wasting the first few feat with cage and seats, as its triple service as in seats, dinette, and fold down bed, crew cab, not so much. My van has a payload of 7900lbs, will end up no where near this, hopefully, and will be off-road capable for my vision which is limited by having a 12' long living space on the back and tall enough to accommodate standing in comfort, with cabover. Not by the capabilities of the van itself. All with a158" wheelbase,
Put 12' on the back of a crew cab and I believe that's a greater limit to any off-roading , again my experience only. Here in B.C. any of the big 550,5500 aren't capable of going anywhere I like to go off-road. I consider them very limited, highway and Fsr only, get into the mountains, with cross ditches and washed out narrow overgrown roads, good luck, I drive these roads daily for work and at one time drove a van crummy bus, realize it must be different in other areas regarding off-road situations.
Don't know if everyone is familiar with Ujoint Van conversions, or Clydsdale, but with a front axle upgrade, some of there builds I would say are off-road capable. I was impressed enough, time will tell. Checked into local legalities regarding adding seats and was basically told do what I want from the girl behind the counter, as registration doesn't list seating capacity? Will be doing more research on this.
 

S2DM

Adventurer
Realize it's not for everyone, or anyone other then myself, you wouldn't be wasting the first few feat with cage and seats, as its triple service as in seats, dinette, and fold down bed, crew cab, not so much. My van has a payload of 7900lbs, will end up no where near this, hopefully, and will be off-road capable for my vision which is limited by having a 12' long living space on the back and tall enough to accommodate standing in comfort, with cabover. Not by the capabilities of the van itself. All with a158" wheelbase,
Put 12' on the back of a crew cab and I believe that's a greater limit to any off-roading , again my experience only. Here in B.C. any of the big 550,5500 aren't capable of going anywhere I like to go off-road. I consider them very limited, highway and Fsr only, get into the mountains, with cross ditches and washed out narrow overgrown roads, good luck, I drive these roads daily for work and at one time drove a van crummy bus, realize it must be different in other areas regarding off-road situations.
Don't know if everyone is familiar with Ujoint Van conversions, or Clydsdale, but with a front axle upgrade, some of there builds I would say are off-road capable. I was impressed enough, time will tell. Checked into local legalities regarding adding seats and was basically told do what I want from the girl behind the counter, as registration doesn't list seating capacity? Will be doing more research on this.

What’s your chassis? I need a chassis cab either way to fit a composite box on.
 

Lwing

Member
E450, it's a 2006, I bought it off a company up in Canada that had 14 of them with only +- 25km, I directed him here and he recently sold another 4 that I know of on here, 6l diesel, by 06 Ford had it pretty close to figured out, I still did a bunch of bullet proofing, the price was amazing in my opinion, US funds would be ridiculous.
 

IdaSHO

IDACAMPER
It sounds like you are itchin' for a new rig, but before going that route I would first consider staying with the rig you have, sliding the bed/box back, and doing a cab-swap.
An extended cab on your vintage truck yields a great deal of rear passenger space, and the suicide door setup I find is fantastic.
 

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