Hello! I did this project over 10 years ago. The only thing that survived is the video you see. I made the drawings in an afternoon to show the concept of how everything works. If you are interested in building it, you will be able to figure out the dimensions that you want for your bike.

Since it was a neat idea and a useful foldable luggage rack for my bike, I want to share this concept. I used it for five years.

Step 1: Things You Need

The bike rack is build from aluminum profiles (C-shape and tube). The
most time-consuming thing you will need to do is to cut four rectangle slots in two aluminum profiles. Tools you need are: personal safety equipment, cordless drill or drill press (better) with drill bits, hacksaw and a file to finish the slots.

Step 2: Concept

The main body consists out of two C-shaped
aluminum profiles (red). Inside, there is another set of C-shaped aluminum profiles (blue) which nests inside when the luggage rack is folded. At the outmost part, an aluminum tube (green) connects the folding C-profiles with flush hinges.

Since the assembly is symmetrical, you will need to make a mirrored half. There is a slider-assembly in the middle, which connects the four hinge points at the center rear portion. When you push the slider assembly, the four blue profiles will get pushed forward. At the outer part, they will be pushed backwards because of the green pipe.

Step 3: Detail: Flush Hinges

For everything to happen, you will need to
create flush hinge points, where the pipes (green) meet the profiles (blue). (Otherwise, when folded, the whole nesting won't fit inside the red C-profile)

This can be done with a slotted plastic pipe, which has undersized holes pre-drilled for a bolt thread. The aluminum pipe (green) and the profile (blue) get a normal or oversized hole. When everything is fitted together, the bolt (brown) is screwed into the plastic pipe and the remaining bolt can be cut flush. This way, the "pin" will definitely stay at its position and creates a nice hinge. Please take a good look at the drawings I made.

Step 4: Have Fun!

I know that it is not a very "accurate" design and there are no specific instructions on what to cut in which length, but if you are motivated and you enjoy figuring stuff out on your own, I wish you as much fun as I had ten years ago with this project.