Idiotic or Inspired?

Single Wheel Trailers

Wait... what?

How does THAT work?!?

Once upon a time, back in the early 50’s Grandpa “Sparky” drove cross-country out to California, much as he had done several decades earlier during the Great Depression. Only then it was as an Okie trying to escape the Dust Bowl, eventually joining the Civilian Conservation Corps (CCC) of FDR’s New Deal and then on to the US Navy where he would find himself on Ford Island smack-dab in the middle of the “Day of Infamy”.

This occasion however, had a much rosier outlook; the middle-aged Navy Chief and WWII vet who would eventually become a walking history lesson was being transferred out to the west coast for his next duty at the Alameda Naval Air Station with a young family in tow.

The family Plymouth was stuffed with small children and supplies, while hitched to the rear bumper was a unique flatbed one-wheel trailer he purchased just for the trip out to the sunshine state…

Over the coming years many moves would follow, possessions and vehicles would come and go, and many more kids would appear before he retired to the beautiful Sierra foothills. But the little trailer would hang around for the next several generations and prove to be incredibly useful.

I can remember playing on it with my cousins and siblings back in the 70’s when it wasn’t in use hauling dirt-bikes out to the races or nearby creek-beds, all of us trying to figure out how it worked. Eventually Grandpa “Sparky” would build an ingenious Swiss-knife style camping box on top, re-christen it “Le 5th Wheel” as a joke and tow it behind his little Ford Courier.

I always had a thing for that funny little trailer, and in Jr high-school shop class when the teacher asked us each to come up with a plan on what we wanted to build for our individual projects, I did not hesitate to say “a one wheel trailer”.  After all, previous students had made BMX downhill-ski bikes and all kinds of crazy ideas. I wanted my own one-wheel camping trailer, badly.

The long-haired, red-head disco era shop teacher stared at me for a moment, then figured I was being mischievous and wry. “No seriously, what are you going to submit as a project?” “A one wheel trailer!’ I insisted. I then went into great enthusiastic detail on how they function, how my grandpa actually has one, and how cool they are which was met with arguments and a dismissal “It will never work” as the man gave up on me and walked away, bell-bottoms swishing sawdust into mini dust devils as I stared at the floor, humiliated.

Decades later I would come to realize there were many reasons why I should have picked a less ambitious project, including difficulties sourcing or machining the special caster-wheel assembly, but “it will never work” was not one of them. Alas, I had been tagged as a troublemaker and spent my semesters making toothpick holders and engraved cutting-boards for Christmas out of scrap material, getting shooed off the machines for his star pupils. The one-wheeled trailer became a faculty joke, and I was crushed when Grandpa’s “Le 5th Wheel” was eventually sold away.

Well Mr shop teacher, it may have taken me 3 decades and countless years of searching, but I now present to you –

The Dysentrailer.

What, me worry?

Because redundancy is redundant.

A custom body of my own design built on a vintage 40’s era Allstate frame; this is my own interpretation of Grandpa’s old “Le 5th Wheel”.

I @#$% told you so.

Known as single-wheel trailers, these simple ingenious devices were popular during the 30’s, 40’s and 50’s but have faded in recent years. However they have remained popular in Europe and with the vintage VW crowd due to their very light-weight. They were offered by numerous manufacturers, Heilite and Allstate being two of the most prolific and well known.

Allstates have a weight capacity of a quarter ton (500lbs) and were offered in kit form through Sears Roebuck mail-order in styles including small metal bodies, a wooden box, a wooden flatbed or bare DIY frames. Heilites came with an aluminum body and removable tent frame that quickly folded out in an early version of the pop-up camper. “One minute to camp!” was their slogan.


All the single-wheel trailers had differing wheel and suspension designs, but they shared the basic concept: two horizontally articulating hitches that attach to either side of the tow vehicle, and one center caster-wheel carries the weight, swiveling for turns. Think reverse wheel-barrow. Instead of two wheels and one hitch, there are two hitches and one wheel. The genius in this design is that it always tracks in-line with the tow vehicle, which makes backing up and parking as simple as, well, just back up and park.

Mounts to frame or bumper brackets

I’ve collected 2 vintage Allstates; the first had been customized to match vintage VW rooftop carriers which I often tow behind the wife’s smart-car when we go camping or on long road trips. We have a large trunk we strap to the trailer which provides fodder for optional smart-car-trunk jokes. I also happened to have purchased the trunk from an ex-nun who left the convent, so I’m not sure if it is a good luck charm or bad.

The second trailer is the covered wagon you see here, built so I can convert it into a camper, stake-side or flatbed in just a few minutes. I often joke that I built it as 1/4th Calistoga wagon but got the math wrong.

For the dimensions I simply placed a piece of plywood on the ground butting up against a wall then laid down, marking just above my head and creating the perfect place to crash at the track. I’ve used it to camp, move, deliver beds, and even hauled it behind Atomic Toasters’ own Killer ZomBee on a 2 week 2,500 mile road trip from hell recently.

Oregon or Bust!

Oregon or Bust!

How does it tow? With most vehicles (MGBs included) on freeways you hardly know it is there. When the curves come up however it becomes a pendulum swinging from the back and slightly urging the car to keep turning. A little countersteer and everything straightens right out. I quickly got used to it..

With the wife’s smart however it gets… interesting. On flat ground it tows just fine. But head up into the mountains, say on a camping trip and as soon as the road gets a little curvy, “Damien the electronic nanny” also known as ESP goes bezerk and tries to kill you. At anything above 25mph left-hand corners are interpreted as a slide, the computer tries to straighten it out by smoking the right tires and putting you in the ditch. Right-hand corners result in the same screaming tires/wife drama only this time jumping into the opposite lane of traffic. “IIIEEE!!”

Talk about a white knuckle ride. The Mrs was NOT amused.

As soon I got home I figured out how to disable Damien by pulling the appropriate fuse, and now it tows as well as any other car. This not only comes in handy for towing weird trailers, but also makes autocrosses fun and causes the car’s @#$%& transmission behave somewhat normal too. Too bad that Super-spouse keeps making me put the fuse back in.

The trailer got its name thanks to a special placard I made up for the trip to Oregon, participating in the Pacific Northworst 24hrs of Lemons race. We did well…

Killer ZomBee, on the Oregon trail

As for the trailer, it’s quite comfy. I’ve learned that a flat tire on a one wheel trailer is kind of a big deal, and people tend to gawk for a long long time. And it was indeed everything I ever wanted.

Wanna know more? Check out for info, and the usually has a couple for sale. Or just keep a look out on I-5 over the next several days… that’s right folks, we’re making an encore trip to Thunderhill this weekend! WOOT! This time with keeper of the KillDozer himself, Jeremy(!)(tm). And yup, of course I’m driving it there…


  • There are still a few holdouts in the microcar world, too.

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    Best wishes at Thunderhill. I understand my niece may stop by to say hi.

    • We may get her back in the car! Now that the wheels all point in the same direction again…

  • The Professor

    Every time I see one of those trailers on the road, one word leaps to mind: "wobbly". I know that's unfair because I know (or now 'knew') nothing about them, but they always looked unsafe as hell. I always wondered what type of lash-up the hitch would be; I envisioned some type bizarro ball joint and tension arm thing. Ah, wrong again. Thanks for the article, it was quite informative, though I still wouldn't touch one with an eleven foot rope. And you tow one behind a SmartCar? You must be mad.
    I see that you've gotten one of the MGs running. Well done! And you can keep it running for the duration of a LeMons race? Well done, indeed. I see that your bodyworking skills have improved too. Good luck in the race, and remember to keep the less filthy side up.

    • Nine races! Some more successful than others (ahem).

      They use the frame (or bumper) of your car as support, so as long as you load it somewhat balanced, AND the car stays on it's wheels they are about as stable as the towing car (even though it looks weird).

      Think less "trailer" and more "self supporting bumper-mounted luggage rack". In fact, the way it is mounted, there has been much debate on whether these are technically trailers or an accessory/extension of the car.

      California is always looking for new ways to collect taxes, so they look at the wheel and say "pay-up, suckah" (shouldn't I get a 50% discount?). Other states would rather you not bother them, and go outside to play with your toy.

      Here's another vid showing one in action. As usual, there are plenty of nay-sayers looking on, but they really are stable. And they will never jackknife when you go too fast.

      [youtube RVp57CV0d7M youtube]

  • old hippie

    The beat up racer is an MGB but the red machine… a Midget? Not enough info but I wish to hell I could find the pic of my owner and her mother coming home with the Christmas tree strapped on the back boot. Priceless, but too damn many photo's to dig through on such a short order.
    Damn but I miss my old '66 Mk2 Midget.

  • Simple and elegant. A very nice little trailer, even if it does mess with the Smart Car's brain.

  • Neat. I wonder if the swiveling function is necessary, though. Why would "steering" be any more essential than it is on a car's rear wheels?

    • Paul_y

      In lane changes at highway speeds, a lack of swiveling probably wouldn't matter, but the second you wanted to go around an intersection or parallel park, the tire scrub would probably put a massive amount of stress on the hub and trailer itself. having a suspended caster just makes the whole thing more maneuverable in tight turns.

      • P161911

        Sure the castor makes it easier, but without it I don't think it would be much worse than the big trucks you see with 2 or 3 rear axles. It would make for a MUCH simpler design.

        • Alas, unlike the big rigs, the scale distance between the rear wheels and the caster is closer to that of the front wheels than a tandem axle (and they use much heavier-duty hardware to boot). If you tried that in a passenger car or light truck you would end up tearing something apart.

          On the rare occasion the wheel gets stuck in a weird position while backing up and turning around, things start to get bendy and awkward REAL quick. The wheel quickly finds it's new direction and resolves itself and disaster is averted, but it is still disconcerting. The more weight involved the bigger the drama.

          When I first got the Dysentrailer frame the caster wasn't lubed & did not swivel as well as it should, and the frame was pretty badly bent. The guy I got it from loaded it up and and tried to turn around. It not only wrecked the frame but destroyed his bumper. Took me a bunch of red-neck ingenuity to get it somewhat straight again.

          I'm pretty sure the original testing back in the day bore this out and made them think "Gee Clyde, this wheel really needs to turn" as they stared at another mangled 32 Ford bumper.

  • Paul_y

    One of my goals when I rejoin the land of the <s>living</s> employed is to acquire/build either a single-wheel or teardrop for camping; either could be towed by my xB with little drama.

    Needless to say, I never comment over here, but I have been enamored with single-wheel trailers for some time.

    • Originally I was going to do a teardrop-single-wheel. The wife suggested I do this instead, proving why she is awesome.

  • Feds_II

    You need to forget the 1 wheel trailers and start putting that roll cage to good use:

    [youtube 56XL0TysIn0&feature=related youtube]

  • Looks like a great light weight way to go! One note though, the pioneers used Conestoga wagons, not Calistoga…

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    • Truth!

      However there are actually a couple of lame jokes/references mashed into my design's name…

  • Roger E. Yaeger

    need a n aluminum 8" wheel for my sears alstate one wheel trailer. can you help??
    Roger 217-285-4685

    • Hey Roger, contributor/author "Sparky" here. I now need a new wheel as well and have NO idea where we can find them outside having them reproduced or buying another trailer for parts. I am in the process of adapting/upgrading mine to a modern trailer wheel for actual road trips. (less drama)

      You might try posting an ad on and Those have the two most active communities I've found for these trailers.

  • Bud Chitwood

    Hello i have a allstate trailer that belonged to my dad i put it behind my 64 mercury comet it shimmy and shook the hole car had to stop and start again it done the same thing about 40 mph any ideas why it has a new tire and everything has been greased Thanks