When my kids were young, we purchased a two-seater bike trailer from Costco that could double as a stroller. That thing followed my bike everywhere. But, as is the nature of children, they grew up. They learned to ride their own bikes and the trailer was banished to the storage shed where it has stayed for the past four years.

While cleaning out the shed recently , we rediscovered the trailer and decided to refurbish it into something a bit more appropriate for my now-older children. Because we often ride our bikes to go shopping, the most logical solution was to transform it into a cargo trailer.

My eight year old son (Jacob) took all of the pictures to document our project.

Step 1: Remove Fabric

Use a utility knife, scissors, or other cutting tool to remove the fabric. The fabric is not needed for this project, so, unless you are going to reuse it for another project, take this opportunity to release some of that pent-up aggression. Hack away!

Unfortunately, after 4 years in the storage shed, the fabric was practically falling off of our frame, so no hacking for us. :-(

Step 2: Take Your Top Off

We don't need the upper frame portion of the trailer, so we are going to remove it. On our trailer, the upper frame was attached with bolts at each of the four corners. Jacob removed these bolts and the top came off in one piece.

We were left with a relatively flat base upon which to build.

Step 3: Select Your Material

Our original idea was to construct an open plywood box and attach it to the frame. My father-in-law convinced me that this was a bad idea. Because the trailer is to be stored outside, an open box would catch and hold water. Holes drilled in the bottom to allow drainage would allow the water direct access between the plies and would deteriorate the wood more quickly. In short, plywood would not weather the weather well (say that five times fast!)

We then looked at mounting a large, plastic storage tote. This had the benefit of being weatherproof and closeable. This would have worked nicely but we decided against it because plastic will tend to deteriorate under the intense sunlight of Central California's summers. Periodic replacement of the tote would not have been a big deal and we would have gone this route had we not found something better.

After a bit of discussion, we realized that to be truly useful for a multi-stop shopping trip, the trailer needed to be enclosed and lockable. Plastic totes, though closeable, would have been difficult to lock securely.

Step 4: Eureka, We Have Found It!

About two years ago, I found a large, wire animal cage in a creek near my house. Being the resourceful gatherer that I am (read: cheap SOB), I brought it home and proceeded to completely ignore it for two years. Until the day of this project.

The cage is 24 inches wide by 36 inches long, which just so happens to be the absolute perfect size to fit on our trailer.

Zip ties at each of the four corners hold the cage to the trailer frame. A more permanent mounting solution would be to use hose clamps.

A padlock on the door secures the contents during multi-stop shopping trips.

And there we have it, a weather resistant, enclosed, lockable, completely free cargo trailer!

Step 5: Making the Connection

In anticipation of the question "How does it connect to the bike?", I am including a picture of the connection that came with the trailer.

The connection consists of a "springy thingy", a clamp, and a safety strap.