Here is a homemade Porteur rack I made a few years back. I got the idea from an Instructables.com idea that used shelf standards for rails. While shopping for the shelf standards I saw the Aluminum angle-iron that I used instead. Fastening it together with pop rivets. Conduit and p-clamps round out the rest of the project. It was a good idea but it couldn't take to much weight without wobbling.

So that evolved into me mounting the Aluminum shelf to a Jand Extreme Front rack I had. That made it much stronger and sturdier. I could carry two 12 packs with this.

But when I upgraded to some new Tektro 720(?) cantilever brakes they interfered with the front rack. Seeing as how I wasn't really using the side rails on the rack, only the top shelf. I did away with the whole thing and bought the smaller front rack that mounts on my cantilevers. I intend on building a new top shelf to accomodate the smaller rack. I don't carry a whole lot, so as long as it handles a 12 pack that will satisfy me.