The Stiffest Bed... In The World

Or that's what Mr. Clarkson would say if he'd seen it.

Hey guys, long post, I was torn between putting it here vs the LT forum, but it's less about suspension and more about the bed, so here we are.



I long traveled my truck, fiberwerx bedsides, Ford 9in custom width, Kings all around, etc... totally different post discussion but you get the idea. The build plan for this truck is to travel from Alaska to Argentina a couple years from now. I spend a lot of time in Baja and the Southwest, and my old Land Cruiser just wasn't cutting it anymore. So I decided to go full send on this build. To go from Alaska to Argentina and do the type of wheeling my buddies and I are into, I essentially needed to build a Baja Prerunner crossed with an Overlander. I struggled for a while on how to execute the bed and living area and came very close to building my own setup in composite, but at the end of the day I decided I have too many projects and not enough time, so I went with the GFC. We have yet to take it out for some real camping (because of the very project I'm writing about here not being complete until now), but the GFC seems like a great setup. It'll need a little extra weatherstripping and foam to keep all the dust out, but it's a great blank canvass for what I'm trying to do.

GFC is the lightest camper out there to my knowledge, ~275lb. My problem was trying to place that on fiberglass bedsides and not break anything flying through the whoops. Composite bed with holes cut out for the suspension wasn't helping any either since I'm essentially missing the front lower corners of the bed.

In the process of this mini-project, I looked all over for bed stiffeners that I could incorporate, but I was incredibly disappointed at how lazily they were designed. Eating up your bed width was a non-starter for me. I could already see myself tripping on that thing and spilling my beer everywhere. I did find one bed stiffener sold by 4wheelparts which looks like a great design and doesn't interfere with the bed interior, but it's discontinued. I called and talked to them on the phone, they don't sell it anymore.

So I said fuck it, I'm an engineer (by education at least), I'll design my own. So here we are. Under the fiberglass bedrail I bonded a steel tube with tabs welded for attachment points in four areas: front, two in the middle, and the rear. From those tabs, I provided support to the shock tube or the truck frame itself to transfer the impulse and load forces properly and avoid stress on the fiberglass bedsides. Mea Culpa: my welding is ugly. Sorry not sorry. Have a great gas mig machine, but sometimes my patience is not there to make it all pretty. It's all about the penetration anyways...

Here's an overview of what we're dealing with...



Now the geometry in each of the four locations is totally different, so I had to CAD up four individual brackets for each location. Lots of foam core board was used in the initial design process -- in the future I'm going to full 3D scanner, ain't nobody got time for foam board anymore!

Support Tubes with mounting points:



My background is aerospace, so I've done a lot of composite work. I went digging into all the options for high quality epoxies from places like 3M and Dow Chemical. Bonding flat steel to not-flat fiberglass with various ridges while maintaining some flexibility was a tricky proposition. After much research I chose 3M's 4200 Adhesive Sealant. Not to be confused with their 5200 product! 4200 is designed to be removable and 5200 is very much permanent. By permanent, I mean when you go watch some videos, you'll see that people have to rip it apart and get destructive to remove it. 4200 is still very strong at 300psi tensile rating, provides the elasticity I need, is removable (not easily, but not destructive either), and met the temperature and surface requirements for this. Not to mention, no two-part mixing required!









The front support essentially clamps onto what is left of the bed and acts as a go-between from our support tube to the shock tube. I also used the mounting point from the original cargo tie-down for additional support and relocated the tie-down itself to the side of the bracket.









The next support aft was a bit of a complicated one because of everything going on there. Since I couldn't directly tie it to the frame or shock tube, I employed a combination of adding structural support and rigitiy to the composite bed, while also attempting to transfer the load down to the shock tube. It's a compromise of a situation, but it's the best I could come up with given the position of everything.

It starts out at the top with the tabs on the support tube which connect to another plate that's bonded to the rib of the bed with 4200 and bolted into a horizontal plate. That horizontal plate replaces a thin sheet metal Toyota plate which conveniently had two mounting bolts into the bed. From there, there's one last bracket which ties into the bed and down to the shock tube. It's not the most elegant, but it's the least worst option.









Aft of that is the simplest bracket of the four. It's a long plate bonded to the bed rib with 4200 and bolted into the support tube tabs above. I gave myself the option to use the two factory bolt mounts at the very bottom either to provide additional security for this bracket, or to mount something else in the future. The 4200 is so strong, I felt zero need to throw bolts in there. So maybe I'll use those holes down the road for something else. I wish they were all this simple.






Last support are the rear tail light corners. In addition to supporting the bedside tube, I also decided to make my own bed corner stiffener since I was pretty unimpressed by all of the options out there.


















Anyways, that's it. Huge pain in the ass, lots of work. Very unique set of problems specifically for this truck, but I thought I'd share.

That said, it occurred to me that maybe some of you would be interested in the tail light stiffening brackets? If it's something you guys would want me to make more of, let me know. Nobody else would need to tie into that upper support tube so that part would be easy to leave off, but the rigidity added from the rest of the brackets in the tail light corner is exactly what we're all looking for when it comes to making those rear corners stiff...and it you won't trip on it. No idea if this would fit other gens.

Thanks for reading✌️

 

Nice write-up. I've always wondered what people with full glass do to properly support a topper or wedge camper like this.

 

I've never got caught up on the Total Chaos stiffeners on my 2nd gen. That includes when I had a non-swing out bike rack and was entering the camper from the side of the tailgate into the rear. In practice, I don't think it's a big deal.

 

WOW you’re craftsmanship and level to detail is great. Good job.

As you know, washboard roads are what ultimately rattle your car apart. I’ve found the cars that hold up best are unibody cars, not body on frame.

So, did you ever consider attaching the gfc to multiple places on your frame?

Just thinking out loud here, not an engineer.

 

Your trip is going to be epic! My friend is doing the trip now (or I think he made it to Argentina) - funny because he has Maryland plates. He drove from Maryland to Nova Scotia, across to AK and the Dalton Highway, then down through Baja, and then into South America. I think he is in Argentina, and trying to ship his truck to Africa next.

Anyways, your truck is so overbuilt, I don't think you will have any issues.



-random internet keyboard/weekend warrior

 

Gents, thanks for all the encouraging replies! It's more a case of stubborn persistence than any actual abilities, haha.

Yeah, I'm not sure most people with full glass and a camper actually do reinforce it. I did a lot of research before starting this to see what other people had done, but (a) most people don't put a camper on top of their fiberglass because they want the cool guy double spare tire setup taking up their entire bed (been there, done that, not worth it), and (b) most people don't whomp on their trucks like my buddies and I do, so you can probably get away without extra support if you're cruising down graded dirt roads.

Good to know you haven't had that issue. The other problem for me, which I didn't mention above, was that I wanted the full width to maximize my space available to build drawer slides on both ends and still have a walkable area in the middle of the bed. We'll see how well that turns out for me when I get around to building the inside......

Thanks man! You know, I did consider different ways of attaching this thing, but after talking to GFC about their attachment points, I felt it was unnecessary and overly complicated to tie the GFC directly to the bed. They say the GFC can go run through the desert whoops and take all the offroad abuse on a stock bed. So I felt my task was to make my modified bed and bedsides at least meet, if not exceed, a stock bed's strength. Do I worry a little about the GFC being bolted into the bed cargo rail system which is bolted to the composite bed with only 4 or 5 bolts? Yeah, it has definitely crossed my mind. GFC says it's plenty though. But you know what, now I'm going to go tighten those bed rails because we're talking about it, hahah. Overall though, I think what I've created between the modified stock Toyota bed, shock hoops, GFC, and all the brackets is a sort of composite structure which increases the rigidity of the whole system when it's all bolted together. At least that's what I tell myself. Another weak point we all know about is the bed itself sitting on the metal frame and slowly wearing away. Nothing lasts forever I guess!

Damn, that's quite the trip. Good on him! Yeah, I can't wait for it. Slightly concerned about the bears though...

Africa next? Mannnn, that one gives me pause. I'd love to do it, but sounds like a lot of those border crossings are tough. I'll just tackle one continent at a time! haha

 

I would be interested in a set of tail light area reinforcement plates if you were to make more.

I have fiberglass trophy truck style bedsides so a topper was a non-starter but I do have a bedcage to bed stiffener mounted RTT. I also have a bed stiffener mounted tire gate from Hotmetalfab that could probably benefit from reinforcement to the existing supports it comes with.

 

Great, glad to hear that. I should probably do some additional measurements so I can cut all the holes ahead of time. Since I don't have a 3d scanner yet, I didn't know exactly where the plates would line up with their opposing backing plates. So the way I did it, I only pre-cut some holes and then drilled/marked on the spot to line up the backing plates. Would certainly be much easier if all the holes existed ahead of time and I think I can do that now that it's installed and I can see where everything should be. Would you be willing to weld it together yourself?