Off road trailer design rules?

[Ozarker]

I have been researching various trailer builds and while there seems to be some "rules" some builds seem to defy generally accepted practices.

For example, having the tounge level to the tow vehicle. Having the width of the wheels of the ideal trailer matching that of the tow vehicle is another "rule". The bigger the wheels the better. For off road trailers some advocate the use of shocks, some say springs only. And, there was something about the length from the hitch to the center of the wheel being related to the length of the wheel base of the tow vehicle. I didn't find too much about the heighth of the trailer other than it should not exceed the height of the tow vehicle, but looking at any travel trailer towed my most SUVs seems this is a suggestion.

Most of the off road trailers I have seen pictures of have the frames set high above the center of the wheels. Most have solid axels running across at the center of the hubs. Obviously the axel must clear any obstacle along a trail so anything just above the axel should be clearing as well. The only advantage I see to going higher is increasing the departure angle.

But putting the frame high above the axel seems to limit the size or height of the storage capacity of the trailer if the overall height should not exceed the height of the tow vehicle. At some point, it appears that a taller trailer will be prone to roll overs. And, the cure for a top heavy trailer is to widen the wheels, but then they may no longer follow the track of the tow vehicle.

Are these issues consistant with how you design a trailer? What are the basically accepted rules to follow to build a great off road trailer? What should you strive for?

 

[gabepari]

While there are many "opinions", the only "rule" that should be followed is "get it done, and go have fun".

Gabe

 

[BorntoVenture]

I've started on the design for my trailer and have been pondering a few of the same questions you've brought up. I also have experience towing loads offroad such as rescue and recovery equipment and can say that the trailer's track width very much needs to be the same or narrower than the towing vehicle. A trailer with a wider track width causes numerous issues in tight turns, so numerous we ended up mounting a Warn 8000i on the rear of the trailer for sliding it around obstacles. Granted this is a large utility body type trailer but you can run into similar issues with smaller trailer that are wider then the tow vehicle.

One design element I'm planning is at least a 20 gallon water tank and dual batteries as low as possible on my trailer. This combined with larger tires and my only real weight way up high will be a RTT so rollover shouldn't be an issue unless I get on some crazy angles. Also even though I'll be pulling my trailer with a fullsize V8 I'm striving to keep the actual trailer weight to a minimum for mileage reasons. Everything will be aluminum except the frame and structural parts.

 

[The Adam Blaster]

I agree that there aren't really any rules that couldn't be thought through using common sense.
Don't make it top heavy.
It can be a bit on the "chubby" side, dependant on your tow vehicle, but if your trailer's weight is all down low, you're probably not going to flip it.
Batteries, water tank, extra fuel tanks, <-- all those things that are heavy should be at the lowest level without ricking them getting smacked on rocks or logs or whatever. (I guess that could be considered a rule.)

I also strongly believe that the design and function of the trailer needs to be tailored to the specific uses of the owner. One size definitely does not fit all.

 

[INSAYN]

I understand the need for the trailer to be off road worthy.... built well, decent balance, track and function. However, I would venture to guess that most folks here pulling trailers probably are overlanding on existing roads and trails that the average 4x4 could make it through, and not so much running the Rubicon. Not to say that there isn't many that do run trails like the Rubicon, but many less than the other. Thus not really a big need to build a trailer to Rubicon specs.

I am in the finishing touches of my trailer and it has to serve several purposes. Making it through a crazy rock trail that my tow vehicle won't even make, isn't one of the purposes. It does have 22" of ground clearance, more for storing items under it while camping, water crossings, and better approach/departure angles on dual track trails.

The main purpose of my trailer is to carry several kayaks, and has an extendable tongue (up to three extra feet) facilitating better clearance behind the tow vehicle.

The next purpose of my trailer gives me a place to sleep when out exploring, using the Autohome Airtop.

I picked up ideas here for my build, but kept it to my needs and intended uses. Not so much what everyone else is using theirs for.

 

[The Adam Blaster]

I picked up ideas here for my build, but kept it to my needs and intended uses. Not so much what everyone else is using theirs for.

Same as I am doing with my build, took lots of tips from here, but it will definitely be one of a kind when it's finished. As it should be.

 

[Ozarker]

Great comments!

Totally agree, get'r done! And proper prior planning prevents piXX poor performance. Looking at the commercial rigs available really helps point anyone in the right direction.

And, it seems that most small trailers spend most of their time, first in the yard, then duty in some utility function and finally for recreational use, at least that will probably be my priorities.

Mine won't be doing any rock crawling, OTH I'd hate to get 6 miles out on a trail with no turn around and find that the road washed out and that my trailer won't make it.

I'd say you need to design your trailer to your tow vehicle. When you have two or more possible tow vehicles designing to the smallest would probably give the best compromise.

My problem is that my primary tow vehicle is limited to 2000 lbs (I believe) a Subaru. Due to the poor MPG of my F-150, it will only be used near home base. That makes weight the enemy.

I guess the first question for any individual build is what is the intended use and type of terrain will be encountered, then design to that. Basic requirements will usually include carrying water, fuel, at least one battery, food and gear.

Seems to me the next thing is to consider what kind of camping will be done or required under various constraints.

Everything seems to be a compromise after some basic requirements. Keeping the trailer balanced front to rear and side to side is a requirement. Balanced with a positive tounge weight, but is there any ratio like 60/40 or 55/45 to the front of the axel?

If there is any rule of thumb like that to be met, then putting a motorcycle ramp on the tounge of a 4X8 might present some problems.....what would they be?

And what about the placement of the axel, dead center on the frame or slightly to the rear for positive tounge weight?

 

[The Adam Blaster]

My problem is that my primary tow vehicle is limited to 2000 lbs (I believe) a Subaru. Due to the poor MPG of my F-150, it will only be used near home base. That makes weight the enemy.

Everything seems to be a compromise after some basic requirements. Keeping the trailer balanced front to rear and side to side is a requirement. Balanced with a positive tounge weight, but is there any ratio like 60/40 or 55/45 to the front of the axel?

If there is any rule of thumb like that to be met, then putting a motorcycle ramp on the tounge of a 4X8 might present some problems.....what would they be?

And what about the placement of the axel, dead center on the frame or slightly to the rear for positive tounge weight?

For the Subaru you may want to look at ensuring you have a tranny cooler installed. You'll save your transmission a lot of misery...

The rule for tongue weight is 10-15% of the total weight of the trailer. Distributing (and securing) your load properly allows you to set that weight correctly.

As for placement of the axle, that can definitely affect your tongue weight, but if you're planning on mounting a motorcycle in front of the main cargo box of the trailer, a centered axle may work well for you.

I think you need to really take a step back at this point.
You have to ask a lot of specific questions as to how and where you want to use this trailer, and also what sort of activity will it MOSTLY be used for.
If you figure out what stuff, and how much of it you want to carry, along with where you need to carry your stuff to, then you can start designing your trailer to meet those needs.

Start at the beginning and move forward rather than jump in the middle and try to work in two directions.

 

[Ozarker]

Absolutely, that's what I was saying about deciding where and how your trailer would be used. Sandy deserts, river banks, gravel bars, rock ledges or whatever together with highways need to be considered.

A tranny and oilcooler are on the list.

The knowledge on this site is vast with experts in many areas as well as newbies. I didn't intend for the tips, suggestions and advice to be about my trailer, just trailers in general. What kind of designs parameters should be followed for a good trailer?

I just wondered if we could get all the good attributes of a good off road trailer in one thread??? :coffeedrink:

 

[The Adam Blaster]

I just wondered if we could get all the good attributes of a good off road trailer in one thread??? :coffeedrink:

Just my opinion but that would be tough considering what I mentioned before about tailoring a trailer for specific needs and specific purposes. A person building a trailer for themselves, only one person that would only see camping/overlanding duties, would be drastically different than a multi-use trailer that would see occassional camping duties for a family of 4 for example.

 

[yeler]

I built mine for the purpose of offroading ie. Rubicon Trail and such trails like it mostly to keep the weight outa my 4 Runner keeping the weight outa my Runner will make it perform better and handle extreme offroading we are primaraly dry campers we take out everything we take it in, but on the same hand we have porta poty and a shower tent that are a must for the wife, everything goes in a box or bag to keep it clean and keeps us from having a "yard sale" on the trail LOL, light weight sstuff ie. tent, sleeping bags and what not go in the Runner and heavy stuff in the trailer.
Got the trailer free and the rest was laying around the yard to make it the perfect build and only took 3 days to do.

http://www.expeditionportal.com/forum/threads/63766-My-67-Mini-trail-trailer

:smiley_drive::campfire::safari-rig::tent:

just have fun and build it right, make it to suit your needs and above all GET OUT THERE AND HAVE FUN

 

[Ozarker]

Yeler, that's a great little trailerfor that extreme 4 Runner. Did you change the hubs or use adapters?

Noticed too that you decided you needed shocks with the springs. Why?

Adam Blaster, double duty is probably what many trailers see, to some extent. Just like Yeler's trailer it started out as a utility trailer, as did mine. It's the conversion process for use off road and redesigning the utility nature of the rig. For those starting out from scratch, the design might be designed for the heaviest demands of off roading as a priority and secondarily with a utility feature, like a detachable ramp or making camper pod system to slide in and out.

I guess the great attributes of an off road trailer can be found in the commercially available trailers that are built. They have been engineered and designed for not only the demands of off roading but also to be towed by a variety of vehicles. I have seen the promos of some of these trailers but they certainly don't say much about the hidden aspects of the design. Maybe someone who owns one can chime in with the details of what makes these rigs so special.

I'm not suggesting copying any commercial rig, but what design features do they employ? And what could make one better?

 

[yeler]

Hubs ??? for what, I have wheel spacers to give me clearance of the tires which match the Runner LOL,, and I dont have shocks, thought of using them to make a smoother ride but unless I find some in the garage Im not gonna use them, as far as comercial trailers yes they are designed and proven but costly, if you have the skills or can get help from friends to build one thats what I would recomend, BBQ and some Beer and you can get alot done on a weekend LOL and make it exactly what you want, mine is purpose built for the trail all be it more extreme than most. But its what I wanted it like any offroad vehicle its never done there is alot more I want to do. Good Luck and whatever you do post pictures and keep us up to date :lurk:

 

[Tucknj]

I understand the need for the trailer to be off road worthy.... built well, decent balance, track and function. However, I would venture to guess that most folks here pulling trailers probably are overlanding on existing roads and trails that the average 4x4 could make it through, and not so much running the Rubicon. Not to say that there isn't many that do run trails like the Rubicon, but many less than the other. Thus not really a big need to build a trailer to Rubicon specs.

I am in the finishing touches of my trailer and it has to serve several purposes. Making it through a crazy rock trail that my tow vehicle won't even make, isn't one of the purposes. It does have 22" of ground clearance, more for storing items under it while camping, water crossings, and better approach/departure angles on dual track trails.

The main purpose of my trailer is to carry several kayaks, and has an extendable tongue (up to three extra feet) facilitating better clearance behind the tow vehicle.

The next purpose of my trailer gives me a place to sleep when out exploring, using the Autohome Airtop.

I picked up ideas here for my build, but kept it to my needs and intended uses. Not so much what everyone else is using theirs for.

I a would be interested in hearing/seeing a Pic of your setup. I am looking at doing something similar

 

[Ozarker]

I a would be interested in hearing/seeing a Pic of your setup. I am looking at doing something similar

I see you're new here

This thread is over 12 years old, haven't heard from this member since then.

While this is my thread started when I was a young man, my trailer is in that backyard gathering rust.

Lots of changes since those days, especially in trailer suspension, so you might check out newer builds.

Why not start a build thread for your project?

Happy Trailers.