Extreme Off Road Bike Hauling Trailer... (1 Viewer)

[Metal Twister]

Extreme Off Road Motorcycle Trailer...Not an Expo Trailer... Bivouac Bravo

I am in the process of building an extreme off road trailer built big enough to haul a dirt bike or other off road toys. The plan is to build it as self contained as practical. The tank less water heater is on its way but before I get too crazy with the options are there any that I should pass on and not install? Everyone talks about all the stuff they put on their trailers but how much of that is really even used?

The trailer suspension is a unique trailing arm and airbag design that Pete at Hot shot racing and I came up with that I'm not quite ready to show off yet. Tires are Goodrich Mudders 35X12 on 15" 6 Lug hubs. Everything like the camper top, side boxes, swing out spare tire carrier, etc. is easily removed in true module fashion. Tow vehicle is an old school 74 fsj 350 v8 soon to be a Big Block 454 with a few suspension mods on 38's.

A few pics of the progress...

 

[scrapdaddy]

Nice Job! I really like the swing outs. I don't have any helpful hints, on what to bring or not. Everybody is different in that area.

What are your plans for the skin. Will it be dust and water proof. I would bet a lot of the off road trailers, being built have a layer of grit on everything, just a pain to keep up with.

Keep up the good work!

 

[Metal Twister]

I was planning on thin aluminum skin except for the boxes on the sides which will be 18 ga. sheet metal. The large openings in the camper shell will open down and act as a sleeping surface and tent material will enclose it. Roof rack could still be an option.

 

[titanpat57]

beautiful..

 

[ntsqd]

As big as that is I think your probable plan for the tongue (guessing based on what I can see) is going to fail in a rather short time. The tongue tubes should be under the main frame's tubes, and very few owner builds that I've seen are done this way. Most of them simply butt the tongue up the the main frame tubes. I know that we all see a lot of trailers built that way and they seem to work, but it is far from a good design.

Picture the trailer, any trailer, hooked up and viewed from the side. There is a "hinge" at the front, full width cross member. Right where the butted-on tongue is butted on! By running the tongue tubes under the main tube you radically increase the strength in this critical area of the trailer frame. Not from the tube being continuous, mostly from doubling the height of the frame in this area. Look at the cheepie Harbor Fright trailer frames, even they have the tongue structure running under the main frame.

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To keep your variable tongue length plan in place I suggest making the tongue an 'A' shape where the legs each go under the main frame front cross-member tube and meet the main frame rail tubes. Set the point of the 'A' a little short of the shortest tongue length that you expect to need. Then run your socket receiver tube from the point of the 'A' back to the same cross-member that your trailing arms are attached to.

The trailer that I bought has an adjustable tongue length. the only time that I use it at all is when I'm moving it around the yard by hand.

Suggest looking into Sikaflex to seal and bond the skin panels to the framework.

 

[Metal Twister]

As big as that is I think your probable plan for the tongue (guessing based on what I can see) is going to fail in a rather short time. The tongue tubes should be under the main frame's tubes, and very few owner builds that I've seen are done this way. Most of them simply butt the tongue up the the main frame tubes. I know that we all see a lot of trailers built that way and they seem to work, but it is far from a good design.

Picture the trailer, any trailer, hooked up and viewed from the side. There is a "hinge" at the front, full width cross member. Right where the butted-on tongue is butted on! By running the tongue tubes under the main tube you radically increase the strength in this critical area of the trailer frame. Not from the tube being continuous, mostly from doubling the height of the frame in this area. Look at the cheepie Harbor Fright trailer frames, even they have the tongue structure running under the main frame.
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To keep your variable tongue length plan in place I suggest making the tongue an 'A' shape where the legs each go under the main frame front cross-member tube and meet the main frame rail tubes. Set the point of the 'A' a little short of the shortest tongue length that you expect to need. Then run your socket receiver tube from the point of the 'A' back to the same cross-member that your trailing arms are attached to.

The trailer that I bought has an adjustable tongue length. the only time that I use it at all is when I'm moving it around the yard by hand.

Suggest looking into Sikaflex to seal and bond the skin panels to the framework.

Well being there isn't a tongue on the traileras of yet I think ya might be getting ahead of things by assuming you know what is going on here. If you were to see under the trailer I'm sure it would be destine for failure as well. Gusset, Gusset, Gusset. Thanks for the insperation.

Harbor freight... Oh please?

 

[ntsqd]

I see what clearly looks to me like a socket receiver tube in the center of the front. What else am I supposed to guess?

Gussets mean squat in this area, you need geometry. See recommended book below. Putting a section reduction right at the high stress area, like the placement of what appears to be a receiver tube, is a big red neon arrow pointing at it saying "FAIL HERE".

The point was that even as shoddy as they tend to be, HF gets it right. So do all of the 1/4t military trailers.

You don't have to take my word for it (see my sig), but if you buy yourself a copy of M. M. Smith's "Trailers: How to Design and Build, vol 2" you'll find that and a whole bunch more very worthwhile info.

If you'd rather that I fawk off and not try to offer sound engineering advice, I will. But if that happens I will pointedly say I told you so when it fails.

 

[Metal Twister]

I see what clearly looks to me like a socket receiver tube in the center of the front. What else am I supposed to guess?

Gussets mean squat in this area, you need geometry. See recommended book below. Putting a section reduction right at the high stress area, like the placement of what appears to be a receiver tube, is a big red neon arrow pointing at it saying "FAIL HERE".

The point was that even as shoddy as they tend to be, HF gets it right. So do all of the 1/4t military trailers.

You don't have to take my word for it (see my sig), but if you buy yourself a copy of M. M. Smith's "Trailers: How to Design and Build, vol 2" you'll find that and a whole bunch more very worthwhile info.

If you'd rather that I fawk off and not try to offer sound engineering advice, I will. But if that happens I will pointedly say I told you so when it fails.

Thanks for the engineering advice as it is truly appreciated. And without getting in a pissing match, solid works hasn't let me down yet. If for some reason it does fail I would be right back here to admit it didn't work. Wait till its finished and then tell me it wont meet the standards of the trailer Gurus. Thanks again for the advice.

 

[goneloco]

This trailer is amazing. I like the size of the trailer and the innovation of the kitchen and other swing outs. Please post as many pic's of the details as possible. If you have some model shots of the solid works model could you post them.
Cheers

 

[Metal Twister]

This trailer is amazing. I like the size of the trailer and the innovation of the kitchen and other swing outs. Please post as many pic's of the details as possible. If you have some model shots of the solid works model could you post them.
Cheers

This trailer is a little bigger than the adventure trailers only because it needs to be able to haul a dirt bike, Pit tires and fuel. It is built a little heavier than need be probably but I will be pulling it with a full sized Jeep with a 350 v8 soon to be a TBI 454. I don't think the weight and length is really going to make a difference. I'm mainly building this trailer as a Racing Pit trailer for Baja, A bike recovery trailer for the So Cal Deserts as well as a camping trailer / Bug out trailer. I wont be posting any specific info as I don't want to stir things up here being the new guy and all. Some of the solid works stuff is linked to the stress testing of the different suspension pivot points. This suspension is un like anything on a trailer as of yet and I am not interested in throwing it out for debate as to its effectiveness at this point. As soon as its done I will show an abbreviated non detailed solid works animation of how it works. Until then I'm going to pass on sharing my solid-works work. I'm just too thin skinned for the criticism.

A pic of the tow rig

 

[John E Davies]

I really like your design, and I want to look at your suspension when you feel able to post details.

What do you think the trailer will weigh, fully prepped, watered, gassed and ready to go, less bikes and other variable cargo? It looks like it might turn porky....... Do you have a full-up weight goal?

What are you going to do for interior tie downs - aluminum track system? Regardless of the number of straps per bike, you are going to need channels for the tires or they will end up sliding sideways as soon as you hit washboard.....

I'm assuming you are going to have at least one spare suspension arm assembly and airbag - do you plan to have dedicated mounting brackets for them? Will the arms be swappable left to right? Adjustable for toe and camber? I know you don't want to show us yet, but a little info would be just good manners.

The main reason I ask is that I am interested in modifying my trailer with better suspension and I can't afford the Adventure Trailer setup and they decided not to sell it as a DIY kit.....

Hint hint.

Thanks.

John Davies
Spokane WA USA

 

[Metal Twister]

Im not really sure what the weight will be? Just depends on which configuration I will be using. If I take of the camper shell and throw on the deck for the RTT it might be a bit lighter. From what I have gathered the RTT's run 185 to 190 lbs. If I take off the removable side swing out storage boxes it should be the same weight as your everyday run of the mill expo trailer. But as I have mentioned here several times already this trailers weight is not my main concern.

 

[Metal Twister]

So I did some calculating last night on the weight of the removable camper shell styled top. I have 84 feet of 1x1x.065 tubing @ .8 lbs per ft. for a total of 67 LBS. I have the 22 feet of 2" x 2" x 1/8" X 1.65 LBS per ft. totaling 36 lbs. for the angle iron base attaching frame. So for the roof as of now it weighs in at 103 lbs total less the awning reel. If I go with the tent top fabric cover I'm sure it will be lighter than aluminum skin. It wont be much more if any than RTT with its platform?

A few more pics of the progress... The first Pic shows it with the new awning mechanism in place. The next two pics are to show the difference in the suspension travel.

 

[Metal Twister]

I really like your design, and I want to look at your suspension when you feel able to post details.

Pete from Hot Shot Racing and I designed and started developing this suspension several years ago and have been working the bugs out of it ever since. I have since moved the shock up inside the trailer parallel to the airbag simplifying things greatly. This does several things for me. First it removes the critical parts of the suspension up into the trailed away from the hazards on the ground. No worries about backing the shock into a big rock bending it beyond use or puncturing an air bag with a branch from a pucker bush or anything for that matter.

If for some reason there is an airbag failure it is easily changed out through an access door in the side of the trailer. No need for crawling around in the mud, snow or dirt to change out and air bag or shock absorber. Air bags are subject to degrading so it is suggested the bags be changed out about every 5 years or so. This makes this process very easy.

This trailer is built extra stout as it will be used for light rock crawling as well as a recovery vehicle for motorcycle racers that have broken in the desert. It needs to be a bit bigger than most to accomplish that. I already have a waiting list of customers who want this suspension on a few different styles of off road trailers so I'm sure you will be seeing the Bengels Bivouac Trailers in a few different configurations very soon.

As promised this is the concept behind the trailer suspension and what I had been keeping as low key as I could.When ever I show this off the Nay Sayers are on this like a moth on light bulb. Change is not easy for most but it is the only way I know to move technology forward. In reality this is a much simpler and more practical system than the standard trailing arms on trailers now. There are several advantages that this system provides that we haven't even spoke of yet. This Solid works model was one of the first concepts we came up with and we have since let it evolve into a more tunable and workable arm. I have built temporary boxes over the mechanisms just to make everyone wonder just how is that thing working with no suspension hanging off the arms.


Solids works design by Hot Shot Racing... Thanks Pete!

 

[NorCal Cruiser]

So I did some calculating last night on the weight of the removable camper shell styled top. I have 84 feet of 1x1x.065 tubing @ .8 lbs per ft. for a total of 67 LBS. I have the 22 feet of 2" x 2" x 1/8" X 1.65 LBS per ft. totaling 36 lbs. for the angle iron base attaching frame. So for the roof as of now it weighs in at 103 lbs total less the awning reel. If I go with the tent top fabric cover I'm sure it will be lighter than aluminum skin. It wont be much more if any than RTT with its platform?

A few more pics of the progress... The first Pic shows it with the new awning mechanism in place. The next two pics are to show the difference in the suspension travel.

Sweet trailer! Are those water tanks in the front corners? What's their capacity? If those aren't tanks do you have room to mount a tank under the floor to help lower the center of gravity? Are you going to carry fuel in jugs or are you going to mount a tank?

I'm looking forward to seeing the finished product!

 

[Metal Twister]

Sweet trailer! Are those water tanks in the front corners? What's their capacity? If those aren't tanks do you have room to mount a tank under the floor to help lower the center of gravity? Are you going to carry fuel in jugs or are you going to mount a tank?

I'm looking forward to seeing the finished product!

It's a good size trailer for off road standards... It's going to be carrying everything needed to pit for a race. I have not decided where everything is going to go but I have played with about 20 different floor plans. LOL In fact I had to walk away from that for awhile, I was going sleepless at night thinking of all the possibilities. Those boxes that look like tanks are temporary covers for the suspension. They will com off once I get the shelves built and skin on the trailer.

 

[John E Davies]

Well, I have to say that is a darned interesting design, but I can't see it ever being retro-fitted to a conventional trailer frame.

How about the shocks? Do you have any overheating issues during long stretches of desert washboard? Do you have any ventilation designed in - louvers in the front and back, for example?

I certainly understand the desireability of keeping the more delicate components hidden away from trail damage, but it seems as if the loss of inside cargo volume and the heat issue might not balance out the benefits.

Shocks can get REALLY hot when worked hard....

John Davies
Spokane WA USA

 

[Metal Twister]

Well, I have to say that is a darned interesting design, but I can't see it ever being retro-fitted to a conventional trailer frame.

Nope me either... Did I lead you to believe that they could ? You mentioned building a knock off A/T trailing arm kit in a previous post. Hint Hint... In the pm I sent you I stated I could build a set of arms in kit form similar to theirs after some research , not a set of my arms?

How about the shocks? Do you have any overheating issues during long stretches of desert washboard? Do you have any ventilation designed in - louvers in the front and back, for example?

Well in the proto type trailer we didn't have any heating issues in the shocks at all being it mounted very close to a one to one 7" of shock stroke and 6" of travel. No heat no louvers.

I certainly understand the desireability of keeping the more delicate components hidden away from trail damage, but it seems as if the loss of inside cargo volume and the heat issue might not balance out the benefits.

Yes It does cut into the valuable space in side of the trailer. A 6" wide box X 8" tall X 12" long wipes out my cargo area.

Shocks can get REALLY hot when worked hard....

Oh John... If it was an issue I would use Nitrogen Fox Shocks with reservoirs but there is not a heat issue any more than normal. Ive built my fill of long travel sand cars and know more about valving long travel shocks than I want to think about. I just wanted to show another option to an off road trailer suspension. Like I said its not for everyone, In fact Im sure it will only appeal to the very serious off road trailer enthusiasts.... and it is not theory , it works very well no matter if you can fathom it or not. I wouldn't of spent the last 5 years testing then build a suspension to show off that doesn't work. See ya in the desert.



John Davies
Spokane WA USA

Bob Engel
Bengels Hot Rod & Off Road Products

 

[PKP80]

Having had my Roll Cage, bumpers, and numerous other items designed, fabricated, and installed by BENGELs. I cannot wait to get my hands of one of these (Sign me up Bob). I have had several shops between Los Angeles and San Diego work on my truck and the only work that has really withstood the abuse is Bob's work. No BS...just my road proven experience. Their shop builds stout products.

 

[scrapdaddy]

Bob,


Let me say up front, how much I like your ideas. New thoughts on stuff is a good thing. I look forward to the rest. Also, I'm an old school leaf spring guy, so


Questions: What are the main reasons for the new design, over leaf springs. Ground clearance, more travel, etc.


Looking at your frame, I can't see the space you have reserved for the suspension. I can see the sink, etc. Please set me straight.


Keep it up!