Do you even *need* a suspension?

[eggsalad]

There was a thread earlier today about building a TTT under 250lb. I was thinking that's a pretty tough goal, as even the tiny HF trailer is 150lb.

Then I started doing some research. I found a boat trailer (in Australia) that weighs a mere 84 lbs!

http://www.mangrovejack.com/trailer/

There really isn't too much to it, it's basically just a long tongue with an axle bolted to it! Could something like that really be the basis of a tear or TTT? Well, why not? We surely have some creative folks on here - who consider *nothing* to be impossible!

One of the things that makes the Mangrove Jack trailer so light is the complete and utter absence of a suspension...

(also the lack of a traditional hub. The wheel itself *IS* the hub! But that's not my topic here...)

I mean... if this design can make due without a suspension, why do we need a suspension at all? Certain tires can themselves act as a suspension, they can be soft and springy enough to absorb road shocks by themselves.

I suppose you would either need to make the cabin very rigid, so road shock wouldn't rip it apart... or go the opposite way and make the cabin flexy, so road shocks wouldn't rip it apart.

Just throwing it out there, to see what the hive mind thinks about it...

-eggsalad

[Woodbutcher]

If light weight is your main requirement you might consider torsion half axles like these. They come in several weight limits. All you would need is a very well built teardrop cabin and a tongue. I would never want a trailer that had no suspension going 65mph.


http://www.southwestwheel.com/store/p-5 ... -hubs.aspx

[Martiangod]

used to live under a mile to the lake, built a so called trailer to haul my 14' aluminum boat down, no suspension, couldn't drive more then about 10 mile an hour otherwise the whole boat and trailer would spend most of its time in the air and skirting all over the place. Now on smooth pavement it would tow ok until you hit a small heave in road then it was airborne again....too stressfull to tow and very very hard on equipment

[citylights]

Giggle! Even horse drawn wagons had suspension!

[KCStudly]

The idea of getting rid of heavy leaf and torsion arm suspensions does have merit, though; for an ultralight.

It makes me think about a very light scaled version of the Aussie style independent trailing link/air bag suspensions, only using neoprene bump stops (becoming more prevalent as a low cost alternative to hydraulic bumps in 4x4 suspension systems).

Daystar Stinger Bump Stop Foam rebuild Kit

Daystar Stinger Bump Stops and Accessories

Might just be soft enough to make a light weight version of a trailing arm suspension.

Other options include bicycle suspension parts.

At 250 lbs, your TD will weigh less than me (!!!) so I expect that bicycle suspension parts would be adequate.

[KCStudly]

...and, take a look at any of the log splitters on the market today. None that I recall seeing have suspensions, and they are heavy compared to what the OP proposes (although they are also not rated for highway use).

I wonder if a trailer for a single PWC or small row boat would be light enough to start with.

[eggsalad]

used to live under a mile to the lake, built a so called trailer to haul my 14' aluminum boat down, no suspension, couldn't drive more then about 10 mile an hour otherwise the whole boat and trailer would spend most of its time in the air and skirting all over the place. Now on smooth pavement it would tow ok until you hit a small heave in road then it was airborne again....too stressfull to tow and very very hard on equipment

I guess my only response to this is that if their customers' boats were being destroyed due to the lack of a suspension, they wouldn't stay in business very long!

The real wildcard that they don't tell us about is the tires. A very soft tire would eat a lot of the bounce.

[rowerwet]

https://www.trailex.com/sut.cfm even the super light weight trailers have suspension, it saves a ton of road impact. puck type suspension could be done, but the cost goes up due to low sales volume, how light do you want your wallet for a few hundred pounds saved?
I would look more into the "frameless" design for saving weight, in the links at the top of the page IIRC.

[M C Toyer]

These, on the other hand, do not have any suspension and are similar to the one eggsallad posted

Trailer In A Bag
http://trailerinabag.com/index.html

The manufacturer claims safe at highway speeds and the users are hauling high-dollar motorcycles.

I am currently finishing a 4 x 8 to haul my dual sport and some camping gear, total of about 500# payload and 850# total. The trailer came with a 3500# axle, 15" tires and leaf springs and does not flex a bit when loaded and only very slightly on washboard gravel roads.

I have two other lightweight 4 x 8 flatbed utility trailers that have the spindles welded directly to the frame. Both have 15" tires and I have no problems or concerns driving at highway speeds with light loads and lowered tire pressure.

[grantstew8]

How about reducing the number of wheels and including some suspension. Details fo build in this link
http://www.thesamba.com/vw/forum/viewtopic.php?t=447117

[DezPrado]

Over here, if you want to travel at highway speed you will need suspension. By law, unsuspensioned trailers may only travel at a maximum speed of 40km/h.
With suspension max speed permitted is 90km/h, 10km/h below max anyway.
I guess I have a need for speedy travel therefore I have a need for suspension

[Roly Nelson]

My 40 inch by 48 inch Harbor Freight trailer weighs 150 lbs. The "Wooden Box" I bolted to it, which I call the "Trolly Top Stacker" weighs only 95 lbs. Together, that makes 245 lbs total. It tows great, sleeps great, though only 6 ft long and feeds many! Light weight trailers can be built, if 1/8th and 1/4 inch plywood is used, along with 1 3/8" hollow core door for a floor.. Just my 2 cents.
Roly, the So Calif woody guy

[Patrickteardrop]

To the OP, I have a question: Have you ever pulled an empty tow dolly? Notice how much it bounces all over Hell if it doesn't have a car on it? THAT is what something that light looks like without a proper suspension. Your teardrop would be no different.

[L.D.]

this brings up my question. my '47 teardrop has no suspension. I am wanting to keep it origanal on one hand, and change it with some kind of suspension on the other. what do I do?

[eggsalad]

To the OP, I have a question: Have you ever pulled an empty tow dolly? Notice how much it bounces all over Hell if it doesn't have a car on it? THAT is what something that light looks like without a proper suspension. Your teardrop would be no different.

Yes I have, and yes, so what? So what if it bounces around? I took my TTT on its maiden voyage last weekend. It bounced around like an empty tow dolly, despite having the lightest-duty springs and tires that exist. So what's the difference between that and no suspension at all?