Heres a quick trailer. Took me an hour to build, it works good:

Ingredients:
2x2 piece of 1/4" plywood.
piece of conduit bent in two dimensions by eye.
a conveniently sized chunk of metal with flanges off an exercise machine.
left over adult sized training wheels.
carriage bolt & eye bolt and locking nuts (enough slop to lean).
bunch of self drilling screws.

http://opengauge.org/pics/rbt3.jpg

Though I love the alicestrong trailing cart post :) Played that one out a few times in my head.

Am I too late to join the party?

http://clients.patcroteau.com/pat/DSCF0002-s.jpg

That's a Wike flat-bed./

I built this from an old tandem baby stroller and wheels from some bikes I pulled out of dumpsters.

The main outer frame is the handle from the stroller. The supports are just the supports from the same stroller.

The tow-bar is electrical conduit and attaches to the trailer with a part from a golf bag caddy.

The hitch, (I'll have to get a decent image of it), is the metal portion from a caster, similar to this one:
http://www.rosebrand.com/images/prod...ber-Caster.jpg
With the caster mounted sideways and the wheel removed, a hitch-pin fits nicely through the hole where the axle used to be. It gives the trailer a full range of motion.

I attached the hitch to the bike using two U-bolts around the chainstay.

I can also put a larger bin on to this baby. I've hauled over 100 lbs of groceries, cat litter and pet food.
It can also hold an airline kennel for hauling our black lab up to the park and whatnot.

Coaster wheel, good idea! I might be able to use that instead of a u-joint for my one wheel trailer.

I dig the caster joint idea. I was thinking of buying a u-joint, but that looks like a great plan!

I made the Carry Freedom bamboo trailer.

It's pretty cool.

Nice! :)

I love your trailer. It looks like you didn't weld anything, all bolted together. How did you connect the u-joint? Have any more pictures of the u-joint connections?

I made this in my 1bedroom apartment, so no welding. Haven't a clue how to do that anyway. Many bolts, the frame is aluminium so it's not as heavy as it might look.

It seems universal joints like this aren't used as often as I had assumed, so I'll take some photos for you tomorrow.

In words, the u-joint I found (apparently from a golf cart) is female on both ends and takes splined 1/2inch shafts. To hook everything up I did the almost same thing on both bike and trailer ends.

1). On the trailer I drilled a hole 1/2 an inch in diameter. From the back I inserted a short 1/2inch bolt.
2). There's also rubber and metal washers in there. The rubber washer sticks to the trailer surface, the metal washer sticks to the rubber washer and provides a hard smooth surface for the 1/2inch bolt head to rest/rotate on.
3). The shaft of the bolt now protrudes out of the front of the trailer. I smothered the threads in 'cold weld' (amazing stuff) and as it hardened I rammed that sucker into the u-joint, thus leaving the perfect imprint of the u-joint's spline on the 'cold welded' shaft.
4). Now the u-joint fits perfectly on this DIY splined shaft; I clamp it tight using the u-joint's own tightening bolt. The coupling now has three orthogonal axes of rotation (u-joint=2, rotatable bolt=1) and the trailer can adopt any orientation.
5). At the bike end the same thing is done, but the analogous bolt is fixed so it doesn't rotate, it doesn't need to. Also, instead of clamping the u-joint to the DIY shaft I drilled a hole through the u-joint+shaft and inserted a pin. This is a quick release way of disengaging the trailer from the bike. Pull the pin, slide the trailer off. Literally takes 3 seconds.

I highly recommend the u-joint method, the trailer doesn't resist any manoeuvres and tracks like an loyal and obedient beast of burden. It's a little complicated to implement compared to the 'strips of rubber' or 'hosepipe' methods.

Great idea, I love it. You have given me some ideas to work with. Time for me to start thinking about size and shape.
The trailer is aluminum? I would never had guessed. What type of aluminum tubing are you using? It's kind of difficult to see from the picture, but I think it is just L-shaped pieces?
I like your design, since I can't weld either.

Here's an image of the underside of the trailer-hitch coupling using the universal joint.

The green thing on the left is the trailer, the green thing on the right is the bicycle hitch. I've shown the cold weld stuff, and an example of the bolt I used. The quick-release pins can be seen in the u-joint. The washers on the left side of the u-joint are there because here the bolt rotates relative to the trailer. The washers offer a surface for the bolt head and u-joint to rotate against. The bolt on the hitch end is held in place by the white plastic strip.

The second picture shows how the bolt has been made into a splined shaft.

astronomerroyal, does that bolt on the left rotate when you lean the bike?

Does the bolt on the left rotate when the bike is leaned? Aye, it does.

If you look at the first part of the movie I posted (see 11-12-07 post above) I am testing the joint, leaning the bike on tight turns etc. Actually, now I watch the video, it's not that clear.

Due to the narrowness of the hitch construction, the trailer can achieve a very tight turning circle (trailer can be ~90 degrees to bike), something surrendipitous and completely overlooked in the design process.

Thanks for the pics. If I can find a u-joint like that, I might do it that way. But most likely, I will just build me own. After my previous post, I started thinking about it and realized that making my own out of u-tubing and square tubing should be pretty easy.

Now I just have to decide on my plans for the trailer itself. I can't decide if I should have the platform even with the wheel axels or drop the platform down about 6" or so. I think having it even would be easier and probably less material, but drop it down might make it more stable.

I also have to think about how to attach the hitch to the bike.

This is a also a Bikes At Work Trailer, which among other things I use to haul around a teeter totter, as depicted here: http://homelessdave.com/images/totter2ontrailer.jpg

I bought mine on ebay, it actually turned out to be two u-joints. Total 15 dollars + shipping. I didn't have the parts to make my own, and was concerned about strength. I do wish I could've found more recycled parts.

Good luck with your design. Now my trailer is finished I think I'm going to start on a second, use up all the spare parts. It's turning into an obsession.

I'm curious, but what size wheels to these trailers use? Does anyone know where to get a 14" wheel?

Don't know about 14" wheel source. BAW trailers use a 16" wheel. They will sell you just the wheels, plus various and sundry other replacement parts here: http://www.bikesatwork.com/bike-trailer-parts/

I love the DIY trailers and here's mine.

People always ask me if the trailer is built of PVC and sometimes think it's fragile but in reality, the PVC tubing was the jig and buried inside is a steel frame (1/2 inch black pipe) that is well braced. I have carried 100 pounds of cargo with relative ease and know I could carry much more.

I'm still looking at doing a few more things like putting a deck under my cargo box and using some angled aluminium to replace my steel cross braces which I always considered to be temporary.

I fabricated the hitch which was semi - permanently fixed to the bike and it uses a u-joint to provide a full range of motion. The threaded pipe joint provides the rotation and allows the bike or trailer to go well off camber without affecting the other. It's my favourite part of the trailer since this and the fact it connects directly behind the back wheel makes it a trailer that handles well at speed.

http://members.shaw.ca/feynn/biking/hitch.jpg

Right after I got her built... the wheelchair wheels (24 inch) are alloy and pneumatic and I have a few more sets of solid core wheels like this for other trailer projects. They have a capacity of 250 pounds and roll very smoothly.

http://members.shaw.ca/feynn/biking/trailer.jpg

Working at our summer bike festival... the trailer was carrying enough stuff to set up a complete workstation and I had also carried a Park rack on top.

http://farm2.static.flickr.com/1138/...59153a.jpg?v=0

During last summer's Bikeology festival my trailer got a good workout and at times I felt like a human SUV... it was a good road test of a one off build that I completed in a few evenings.

As a fellow u-joint proponent I must commend you on your design. It's also may favoured part of my trailer. Anyone who appreciates a good mechanism can't help but love the u-joint. I like the idea of non-bike wheels, I was looking for an oddly sized wheel, 14", and might look to see if that size exists in non-bike wheels. Just took my trailer (12" wheels) through 5" of snow, the trailer became a snow-plough. A complete joke.

The arms of your hitch, are they sufficiently rigid to dstop the hitch flexing side to side? I'm starting to get the feeling I massively over-engineered everything.

Homeless Dave, thanks for the information. Soon I'll come to terms with the idea that 16" wheeels are my only alternative to 12". When my 12" rims came in the mail I almost choked to death on my scoffs. They looked ridiculously, laughably small. In my naivety I thought at the time that 12" was the rim diameter. However, no-one has laughed at me yet, even the gangs of kids I've passed. It's weird, you can buy a children's bicycle with 14" wheels, but you can't buy 14" rims separately.

astro - I actually added a drive side support (it's there in the second pic) as there was a tiny bit of flex that wasn't problematic but something I thought might lead to some fatigue issues.

I am presently re-working by bike's hitch and fabricating a new mount by using stainless rod which will be stiffer and more elegant and then I can use a single arm mounted to the non drive side.

I like the larger wheels as with bicycles, a larger wheel might tale a little more to get it up to speed but once they are rolling they are more efficient and ride far better.

I will be towing this bike through the winter and not having the trailer turn into a snowplow was also a consideration in my design.

A one-sided hitch? I'd like to see how that works out, especially how it handles the lateral forces, and the large torques at the points where it's fixed to the bike. You obviously have it all figured out.

As for snow-ploughs, admittedly my trailer only turned into one when the snow was too deep to actually cyclke through. Still, fine adventuring. I wouldn't discount 12" wheels on 'snow-plough' grounds.

Most trailers only mount on one side of the bike but have an offset to the trailer arm whereas my design has a permanent arm attached to the bike with an offset which puts the hitch point directly behind the wheel instead of at the side.

Having the load point directly behind the bike really makes the trailer stable under load and at speed and I can turn the bike and trailer around in very small circles as I can turn beyond 90 degrees in either direction.

The extra strength and lateral stiffness of a stainless rod over flat bar stock should make it possible for me to use a single non drive side mount and if not...adding a stabilizer will be rather simple.

I'll update the pics when I get the new attaching arm built and attched to my new tow bike since that lovely Kuwahara has since become a fixed gear.

I do have a question about that hitch point. How does it do stopping? It seems since the mount point is behind the rear wheel instead of next to it, it would want to push your bike to one side or the other, especially when you're turning and stopping. That was the reason I decided to try the basic 'side of bike' hitch instead of what you have.

I have not had any issues with stopping when I have had the trailer loaded (80-90 pounds) and when it's empty I can hardly tell that it's there.

Bikipede - an articulated double bicycle trailer.
 

Bikipede - an articulated double bicycle trailer

I recently finished my second trailer, but this one comes with a twist: it trails behind the first trailer, a little like the 'road trains' they have in Australia. Once again the coupling is the beloved rotating u-joint. It's a very similar design to the first trailer (actually an upside down version), but with more capacity and none of the electronics/gadgetry. I was prompted to do this by the spare u-joint I had lying around after finishing trailer #1. Having gone through the process of building trailer #1, the second trailer only took 3 days to make from scratch. Parts for trailer #2 probably cost no more than 120USD, so the entire bikipede cost about 300USD to make (including considerable shipping costs). Worth every penny, in my distorted opinion.

Performance is generally excellent, I couldn't be happier. Trailer #2 has wheels shifted slightly forwards, more towards the centre of the bed. This establishes a better balance with the load, and thus exerts fewer load-related stresses on the back of trailer #1. Understandably, the 'tri-axial' u-joint inbetween the trailers, and the protuding hitch on #2, means its turning abilities are also very orderly. Both hitches allow turns at almost 90 degrees. One thing it definitely can't do, however, is go backwards.

I've attached some screenshots from a short movie that covers its construction, and so on. The third image (looking backwards from the bicycle) is meant to give an impression of its snake-like articulation.

Because it moves much like a centipede or millipede, my girlfriend (the glamourous model in the images) suggested calling it the Bikipede, but Cyclopede also sounds good to me. Which should it be?

My best regards, as always,
A.R.

Velocipede.

Genius. I shall inform the girlfriend of the new old name. Thankyou.

I'm not sure if this counts because it was built for a bike event and was only used once for actual cargo hauling. The trailer is a metal frame made of hand bent 1/2" conduit with the trailer cargo body being made of plywood and various dimensional lumber. Wheels were taken from a 12.5" kids bike. I almost flipped the trailer coming down a hill during the event so it was dismantled shortly thereafter. I'm working on a new cargo trailer that will be more practical. I did win "Best Decorated Bike" at the event the trailer was built for so it could be argued that the utility of the trailer was not in cargo hauling ability but in award winning (the purpose for which it was built).

http://i64.photobucket.com/albums/h1...Ryan/tdl_1.jpg
Me with the bike and trailer

http://i64.photobucket.com/albums/h1...rize_Cycle.jpg
Real men glue plastic rhinestones to their homemade panniers.

http://i64.photobucket.com/albums/h1...n/P1010046.jpg
During the building stage

http://i64.photobucket.com/albums/h1...n/P1010048.jpg
and of course I added a "share the road" sticker (complete with LED spotlights shining on it)

-----------------
This is a prototype of a hitch design, it was scrapped in favor of a better one for the new trailer in the works.

http://i64.photobucket.com/albums/h1...yan/hitch3.jpg
http://i64.photobucket.com/albums/h1...yan/hitch2.jpg
http://i64.photobucket.com/albums/h1...yan/hitch1.jpg

-Ryan

Ryan, are those ammo box panniers?