5-7x12 Overland build Thread

[Murdy]

Hi everyone! I've been building my trailer now for a few months... but entirely in my head, and mostly at 3am when I can't sleep! Hahaha!

I'll start with a description of what I'm planning, and hopefully you all can chime in and tell me where my bad ideas are before I turn them into reality.

So... as mentioned in the title, it will be a 12' long build. The "5-7" portion of the description is because the front will be 5' (wide enough for a queen mattress) as will the entire interior. At the wheels, I'll be building the frame out to expand around the wheels. Above the wheels will be compartments to hold gear and utilities on the one side, and an outdoor kitchen on the other. The height of the trailer is not yet determined as I have not officially decided that I will be building the pop top that I want. Assuming that I do, I'll build it tall enough that I can fit our dirt bikes in the trailer. That of course leads me to the fact that I'll have a cargo style door on the back to allow for loading bikes and/or animals when hunting. If I decide against the pop top, the interior height will need to be 6'3" in order to eliminate ****** bombs when smashing my head. (I'm 6'1")

I'll be building it so that the tongue height will be at right around 24". As I'll be aiming for a total dry weight of less than 2000lbs and a max GVWR of 3500lbs (although I plan to only use that in the extreme circumstances), my intention for suspension will be tandem Timbren axle-less 1Tonne HD with e-brakes on one (front I assume would be the smart option???). I'll be matching hubs with that of my tow vehicle in order to have multi purpose spare tires. (5x114.3) Worth mentioning is that if I can figure out ways to save enough weight, I could switch to a single 5200lb system... although I wouldn't be able to have matching wheel hubs then. Any thoughts here?

On that note, the tow vehicle is a '21 Rav4 TRD offroad (rated to pull 3500lbs). I've lifted it 2", and she'll be getting new boots in the spring. I'm certainly open to suggestions, but I'm leaning towards Either Nitto Terra Grappler G2, Goodyear Duratracs or Falken Wildpeak AT3W (245-70-17 @ 30.5"). The tires that I took off of the car (Falken Wildpeak AT Trail 225-60-18 @ 28.6") will be used as the trailer tires.

Now... because I'm crazy and live in Canada (2 separate statements there for the record... haha) I'm hoping to be able to integrate a small removable hatch in the trailer floor/deck in order to be able to use this as an ice fishing shack in the winter as well.

Now is where I need to request some assistance. I have a couple utility trailer plans that I've found that I'm sure I can modify to make this happen... but I'm struggling to find info on various steel strength equivalents. As this build is going to be off-road, I'll obviously need to beef things up from a regular utility trailer. I'm confident that I can do that without issue, however I tend to overbuild, and I'm going to run into challenges making this build happen within the 2000lbs dry weight (or less) that I need. I need to do this build as efficiently as possible to make that happen.

So... as much as I searched and searched, I'm hoping that somebody out there with a better understanding of metal strengths can help me out. I'm currently quite seriously thinking about building in aluminum as well, but this creates new issues. Is the cost worth the weight savings? And will aluminum be a good choice for the build? With steel, I can fab everything in my garage, and tack weld it. If at that point I'm not comfy with welding it out, I have friends who can bring a proper rig over and buzz it out. Aluminum would likely have to be fabbed entirely for me at a shop... and the materials and welding are significantly more expensive. So... the question is, CAN I build this in steel at the weight that I need, and if so, would the cost of aluminum be worth the weight savings?

I've searched the forum, but have not found what I'm looking for. I apologize if this info has been missed. If you have opinions, info, links, etc, please, let me know.

Soon I'll be using Sketch up to get my ideas into a hard copy. Once that happens, I'll post them up here. Currently, my mission is to get materials (specifically my suspension) ordered up as there is a lag time on that right now.

 

[Timbren]

Hey @Murdy, welcome to the forum. If you need any assistance picking out the suspension give us a shout. We love a good trailer project.

 

[Murdy]

Hey @Murdy, welcome to the forum. If you need any assistance picking out the suspension give us a shout. We love a good trailer project.

Well.... I reached out to your crew 2 times. Once via email got me a guy who seemed to have no interest in my questions. He gave me a small handful of generic answers.

Shortly thereafter I called in and spoke with Lou (I think was his name), and got a lot of great info from a guy who is either very passionate about his job, or is really good at pretending! Haha!

As the answers that I got were very different, maybe you can give me a 3rd opinion? What are your thoughts on this build? Which would be a better option... Dual 1T HD, or a single 5200? Obviously the duals will add more weight, but they'll also even the load across the frame rather than at one point. As I've been crunching unofficial numbers, I'm quite sure that I can come in under 2000lbs dry even with the dual 1T. That said, I do want the ability to put a moose in the trailer, so I need to allow for 1000lbs plus gear.

Any thoughts on the advantages and disadvantages of single vs dual?

Thanks!

 

[Timbren]

Hey @Murdy, we chatted with some of our design team and based on the dry weight of your trailer and your specific project needs we recommend going with tandem 2000 HD’s. Within that lineup you can select between standard height, 4” lift and 4” drop to get your ride height where you want it. On each one of those product pages you’ll also see the hub and brake combinations that are available and fit the 2000 HD’s.

As for your frame - Aluminum is significantly lighter, however, to obtain the same level of strength you would need to use more of it and fabrication usually costs more with aluminium as well. The cost of running an aluminium frame may outweigh the benefits. Just food for thought while you’re figuring out which direction you want to go.

Hope that helps!

 

[Murdy]

Hey @Murdy, we chatted with some of our design team and based on the dry weight of your trailer and your specific project needs we recommend going with tandem 2000 HD’s. Within that lineup you can select between standard height, 4” lift and 4” drop to get your ride height where you want it. On each one of those product pages you’ll also see the hub and brake combinations that are available and fit the 2000 HD’s.

As for your frame - Aluminum is significantly lighter, however, to obtain the same level of strength you would need to use more of it and fabrication usually costs more with aluminium as well. The cost of running an aluminium frame may outweigh the benefits. Just food for thought while you’re figuring out which direction you want to go.

Hope that helps!

Ten4! Thanks for confirming the route that Lou had suggested.

I'll likely be putting an order in shortly.

As for choice in metal... Yes, I'd pretty much resigned to steel being the better choice for me. As much as I'd like the weight savings, it would put me back a ton in order to make it happen.

 

[Timbren]

Yeah, I think running steel is a solid choice. Welcome to the Timbren family @Murdy ??

 

[OldGreen]

It looks like you are building something like mine...minus the dirt bike and ice fishing part. I am a tiny bit farther along and happy to help.

 

[Murdy]

Looking good so far!! Are you skipping the cargo trailer portion entirely, or dirty bikes specifically?

I've done a fair amount of planning so far, and the suspension should be on the way by now... I hope...??? Steel would have been ordered up on Friday, but the guy never got back to me to take payment. In looking at your build, perhaps that's a good thing.

What made you decide to go 3x2 cross members? I was going to do 2x2 with the main rails being 3x2. With a potential of hauling a moose in this little beast, maybe I should be reconsidering?

It looks like you are building something like mine...minus the dirt bike and ice fishing part. I am a tiny bit farther along and happy to help.

View attachment 651229View attachment 651230View attachment 651233

 

[Murdy]

Here is as far as I've currently gotten. The left side (from the front) was my original plan (with a step in the angled portion). The right side was an after thought that came up this morning when I got to work. I'm pretty sure I'll go with the right side as it will give me extra space inside for little bed/couch side tables and such.

The left side will have a toilet and black tank in the back corner, and an outside shower, all utilities (pump, on demand water, etc). The right side will have a big hatch for an outdoor kitchen.

 

[OldGreen]

Looking good so far!! Are you skipping the cargo trailer portion entirely, or dirty bikes specifically?

I've done a fair amount of planning so far, and the suspension should be on the way by now... I hope...??? Steel would have been ordered up on Friday, but the guy never got back to me to take payment. In looking at your build, perhaps that's a good thing.

What made you decide to go 3x2 cross members? I was going to do 2x2 with the main rails being 3x2. With a potential of hauling a moose in this little beast, maybe I should be reconsidering?

No cargo trailer at all. Just similar in dimensions to yours. . .5.5x12x6'2". There is only one 3x2 cross member beyond the main rectangle and the connector between the Timbrens. The one that the tongue butts into. The rest of them are 2x2x3/16 angle. It is PLENTY stiff for 3500lbs. Also, I understand wanting to keep the 5 bolt pattern, but if you are ever fully-ish loaded and have to air down, the scrub on dual axles will increase your chances of loosing a bead. In fact, trailer rated tires with extremely stiff sidewalls are recommended with dual axles while regular LT tires are good for single axles. I posted a build thread for mine just now.

 

[Murdy]

No cargo trailer at all. Just similar in dimensions to yours. . .5.5x12x6'2". There is only one 3x2 cross member beyond the main rectangle and the connector between the Timbrens. The one that the tongue butts into. The rest of them are 2x2x3/16 angle. It is PLENTY stiff for 3500lbs. Also, I understand wanting to keep the 5 bolt pattern, but if you are ever fully-ish loaded and have to air down, the scrub on dual axles will increase your chances of loosing a bead. In fact, trailer rated tires with extremely stiff sidewalls are recommended with dual axles while regular LT tires are good for single axles. I posted a build thread for mine just now.

Haha.... well, in my research and question asking that certainly didn't come up. I've already ordered everything up, so hopefully I don't end up in that situation!! Hahaha! Realistically, with my pull vehicle, I'm not looking to do any hard core off roading. Light trail, nothing crazy.

Looks to me like you're running 16" centers... yeah?

Apparently I didn't look close enough to see that only 1 was a 3x2... perfect!! Thanks

I'm going to do my tongue underneath and 2 solid 3x2 angled back and welded under for extra rigidity.

 

[OldGreen]

Haha.... well, in my research and question asking that certainly didn't come up. I've already ordered everything up, so hopefully I don't end up in that situation!! Hahaha! Realistically, with my pull vehicle, I'm not looking to do any hard core off roading. Light trail, nothing crazy.

Looks to me like you're running 16" centers... yeah?

Apparently I didn't look close enough to see that only 1 was a 3x2... perfect!! Thanks

I'm going to do my tongue underneath and 2 solid 3x2 angled back and welded under for extra rigidity.

18" Centers. My floor is extremely rigid.

 

[Murdy]

18" Centers. My floor is extremely rigid.

Who makes those panels?

 

[OldGreen]

Who makes those panels?

I do.

 

[Murdy]

Aluminum/foam sandwich?

I do.