Building your own trailer should be easy on the pocket and easy on the planet. There are quite a few sites out there offering instructions on how to build your own bike trailer, often out of reused bike parts and often needing no welding.
The trailer above fulfills both criteria and the instructions are available via the Re-Cycle webite here>>
Additional comments on the same trailer are available here >>
DIY Longtail (Xtracycle style)
Another diy project that needs no welding – this time a longtail cargo bike.
In 2013, two of us cycled to The Gambia from northern Spain to work on a bicycle recycling project. With the help of a local welder, we created a similar longtail cargo bike, as seen below.
The full article relating to the building of this cargo bike can be found here>>
Another cargo bike built in the Gambia, this time in a Long John style can be found here at Atomic Zombie