For couple of weeks in a year, the partially frozen or flooding river makes it impossible to use a boat, and there is not enough snow to haul heavy stuff to our hunting cabin using a sledge. Being well prepared in advance, those few weeks usually are not a problem at all, but it would still be nice to be able move things by some easier way than by making several round trips dragging a fully loaded backpack. Therefore, I decided to build a cheap walking trailer, not weighing more than 10 kg (22 lbs), hopefully capable of handling at least 50 kg (about 110 pounds) load on an uneven terrain.
For serious hikers there are some very nice monowheel trailers commercially available. Good monowheel trailers can be pulled through relatively difficult terrain. Problem with the mono wheels is that in order to maintain good balance of the loaded trailer, both the frame and the pulling gear must be made of very rigid materials, which tend to be ridiculously expensive and difficult attach to each other with the tools that can be found in every household.
Since I’m not planning to drag a trailer in a pathless forest, and I do not have equipment to weld aluminum or laminate carbon fiber, I ended up with a plan to build a simple two wheeler using no more than 70 euros for the whole project.
The original design was to build a flat 0.5X0.5 m (20X20 in) deck on top of two 12 inch wheels, and connect it to some military surplus harness using two rigid poles.
First I went to a local bike shop and asked the price for the front wheel of a children’s bike. When a cheap bike costs less than 100 euros, I was a bit shocked to hear that just a front wheel (no tires included) was 35 euros. It seemed like just the wheels would break my budget. So, I walked out of the shop and googled the local flea markets. After a quick search, I found a nice little bike for 20 euros. Instead of buying another bike, I decided to use both of the bikes wheels for my trailer project. The gearwheel and the brake bits were not that difficult to remove from the rear wheel, and I didn’t believe that the small difference in the width of the axles between the front and the back wheels would cause too much trouble (which later proved to be true).
For the frame of the trailer I used two 42X42 mm (1 2/3 X 1 2/3 in) 0.5 m (20 in) long pieces of wood (local hardware store didn’t bother to charge for those). To make the frame pieces wide enough to accommodate the fork structure for the wheels, I glued three pieces of 2 cm (4/5 in) thick wood to the both sides of both of the frame pieces.
For the forks, I used four 25 cm (10 in) long pieces of 3 mm (about 1/8 in) thick flat iron. The supporting structure was made from 2 mm (1/12 in) flat aluminum. Two of the flat aluminum bars were left a bit longer than the others to support the rear end railing made of a 6 mm (¼ in) threaded rod covered with a plastic tube.
Then I finished the deck with 12 mm (½ inch) wooden bars and supporting pieces of flat aluminum.
For the pulling gear, I happened to have a 2 meter (about 7 feet) piece of round 20 mm thick (about 4/5 inch) wood. To reinforce the pulling bars, I inserted them into 20 cm (8 inch) pieces of steel tube, and drilled the necessary holes for the assembly.
Since I’m going to be the sole user of the trailer, I attached the pulling gear in the fixed angle. For a multi user version, one must design some kind adjusting system. At this point it was absolutely essential to measure the angle very carefully so that the pulling bars are at comfortable level on your waist and that in the same time the deck of the trailer is level to the ground.
After some trials and errors, it became obvious that for the required rigidity, in addition to the attachment to the frame, the pulling gear needs two supporting points. For the supporting structure, I bolted two pieces of flat aluminum between each of the pulling rods and the frame of the trailer.
For the actual pulling harness, I combined a surplus German army military belt (5 euros) with a surplus Alice suspenders (a copy of Alice made for the former Yugoslavian army, (3 euros)). The pulling harness does not have to be German-Yugoslavian, any rugged, relatively comfortable harness works equally well. (I say relatively comfortable because it is truly surprising how small amount of weight or pulling actually comes to your shoulders or waist.)
To attach the pulling bars to the harness, again after some trials and errors, I decided to drill a small hole through the pulling bars, push some paracord or equivalent through the hole, wrap it around the pole couple of times , tie a loop to the paracord, and use the loops to attach the bars to the harness.
Of course it is possible to design more or less “tacticool” attachment systems, but based on my experience, the paracord loop system is easy to make, adjust, and if necessary, to fix in the middle of nowhere. A two meter (about 7 ft) piece of paracord, which can be used for many other purposes in camping conditions as well, is pretty much all of the spare parts one may need to fix the pulling gear.
I made my walking trailer couple of months ago, but I didn’t want to publish any instructions before some test rides were completed. Therefore, after some initial short tests, I took a nice little 55 km (about 35 miles) stroll with a friend of mine, loading the trailer with some 30 kg (about 65 lbs) of stuff. (The stuff was bound to the trailer with cheap bungee cords). After 55 km on asphalt, dirt roads, and some relatively uneven hiking paths, there were not to many things to complain about.
The trailer was nice, easy, and surprisingly light to pull. 12 inch ground clearance was quite enough, and the whole load stayed where it was supposed to stay through the whole trip.
The only thing I would have changed was the length of the pulling bars. In my original design, the bars ended to my waste, and occasionally it would have been nice to have some handle bars in front of me to steer or support the trailer through tight spots on the path. Therefore, I decided to replace the original bars with the new, about 40 cm (15 inch) longer ones.
Before changing the bars, it was time to test the real weight handling capacity of the trailer. For that, I had an opportunity to haul some 25 kg (55 lbs) bags of concrete on an uneven terrain. 50 kg (110 lbs) was easy. The same was true with 75 kg (165 lbs). 100 kg (220 lbs) was surprisingly light and easy to haul, but on one, kind of a sharp bump, both of the pulling bars cracked. No other damage to the trailer though.
The last test proved that my simple cheap home made trailer is capable of handling a lot more weight that I would ever imagine trying to make it handle, and that the weakest part of the trailer was the pulling bars (which I was going replace anyway).
Based on my experience from the trailer project, I can pretty safely say that it is possible to build a decent walking trailer weighing less than 9 kg (about 20 lbs) for dirt roads and relatively easy hiking trails using cheap materials and household tools for less than 70 euros.
List of parts:
1 m (40 in) wood (42 X 42 mm (1 2/3 X 1 2/3 in)) 2 € (usually for nothing)
4.5 m (15 ft) wood (42 X 12 mm (1 2/3 X ½ in)) 6 € (or free from discarded hat shelf)
Six small pieces of wood (20 X 42 X 100 mm (4/5 X 1 2/3 X 4 in) (ask any carpenter or hardware store for free)
two 12 inch Wheels (used children’s bike) 20 € (70+ € as spare parts for big spenders)
Two 140 cm (55 inch) Pulling bars (22 mm (7/8 in) diam.) 5 € (Broom sticks are good for this)
1 m (40 in) flat iron (3 X 30 mm (1/8 X 1 3/16 in)) 2 €
6 m (20 ft) flat aluminum (2 X 20 mm (1/12 X 4/5 in) 24 €
50 cm (20 in) steel tube (20 mm (4/5 in) inner diameter) 1€ (or abandoned piece from a coat closet)
50 cm (20 in) threaded rod (6 mm (¼ in) diameter) 1 €
50 cm (20 in) plastic or rubber tube (6 mm (¼ in) inner diameter) 50 c
Surplus military belt 5 €
Surplus military suspenders 3 €
Nuts, bolts, wing nuts, screws, and washers 3 €
The final cost of my project was 63 € 50 c, which, in my opinion, was quite reasonable price for a very usable walking trailer weighing less than 9 kg (20 lbs). With any luck with friends and relatives with small children, and the content of your scrap boxes, the costs can easily be less than 40€, and even if you start with absolutely nothing and buy everything from the shops, it is very difficult to use a lot more than 100 € for the whole project.