Intro: Single Wheel Bike Trailer
At the beginning of the spring season, while sun begins to shine in South of France, I decided to build my own bike trailer. I read many trailer comparatives in order to find the best solution corresponding to my needs.
I intend to have a trip along Canal du Midi during the summer for at least 3 days with friends of mine and using backpacks or racks did not seem to be very pratictal. The idea of a trailer in which you can easily put the tent mattress and any stuff you want came to me.
Step 1: 1 or 2 Wheels ?
I read many forum topics about the question...
As the road will be a single track for many kilometers, a single wheel trailer seemed to be the best solution.
I discovered two main trailer constructors:
- Bob (http://www.bobgear.com/ )
- Aevon (http://www.aevon-trailers.com/)
These constructors use different fixing solutions. Bob trailers use rear axle fixation whereas Aevon ones use seat tube solution.
I decided to make a trailer as similar as possible to the Aevon trailer.
Step 2: Material Collection
I bought :
- 8 meters of 1cm square steel tube (less than 1kg per meter)
- 2 meters of 2,2 cm square steel tube
- 0.5L of shiny black paint
- 2 “heavy duty” axles
- a 16” wheel
- 1 forch from a 16” bike with its mudguard
- 2 meters of used round tubes (old badminton poles)
- Steel offcuts
Total cost : 30€
Step 3: Central Section Assembly
I welded the forch to the 2,2cm square section. This section aims at consolidating the trailer on its bottom and is also used as a trailer shaft. From the rear of the trailer to the bike hitch, it has been cut in 4 parts :
- Bottom part of 78 cm
- Front part of 44 cm
- First part of the shaft of 35 cm
- Second part of the shaft of 42 cm
Step 4: Trailer Hitch
This step is the trickiest one. In fact, the hitch has to be strong enough to support the effort of a 12 of kg of luggage in bumpy conditions.
The first solution, retrieved from this instructable (https://www.instructables.com/id/SURF-FISHING-CART-TRAILER/step9/Trailer-Hitch/) consisted in using a caster wheel as a hitch. The result was not satisfactory on a single wheel trailer. The trailer was not horizontal, it was inclined on the left.
The final solution is an homemade solution consisting of 2 X 4cm round tubes perpendicularly welded, forming a crosspiece. The vertical part is on bike side and the horizontal one on trailer side.
On bike side, a steel piece has been welded in order to attach the vertical axle. This piece is fixed to the seat tube using 2 U-shaped screws. In order not to deteriorate the seat tube, some inner tube piece has been placed between metal parts and the seat tube.
On trailer side, two perforated iron parts have been welded on the trailer shaft to receive the horizontal axle.
Step 5: Removable Shaft
In order to store the trailer more easily, the shaft had to be removable. It was cut 10 cm from the trailer.The coupling between the 2 shaft parts is performed with a square tube welded around the shaft on bikeside and in which the “trailer side” of the shaft enters. Then a screw interlocks the shaft and the external square tube.
Step 6: Trailer Pannier Frames
2 frames were constructed with 1cm square tube of steel:
- 76 cm x 40 cm bottom frame
- 112 cm x 40 cm top frame
Both frames are linked with :
- 2 x 40 cm sections on front side of the trailer
- 2 x 25 cm sections on rear side of the trailer
The resulting pannier was welded to the 2cm square central axle of the trailer.
At the bottom of the pannier, 2 sections of 38cm were welded in order to consolidate the trailer.
On both sides, 2 round tubes were riveted on the trailer to prevent the bags from falling of the trailer.
When all parts were welded, I brushed it then painted it shiny black.
I tested it on small rides of about 50 km. I loaded it with my backpack a tent and a sleeping bag and went on dust tracks. The trailer had a good behaviour, following the bike track while turning. I did not weigh it but it is really easy to tow and did not handicap me. i will buy a high volume waterproof bag to put in it. Next step is to use it for what it has been designed : an autonomous trip of several days...