I was inspired by this bike which is much more beautiful than the one I built. I built the bike in Haiti, with a minimum number of tools and ingredients. I would have posted this a couple months ago, but was delayed because as I was taping the stencil on the frame, Haiti was struck by 7.3 magnitude earthquake. Costs for this bike were $25 for the bike, about $10 for steel, and $5 for welding rods. With the seat tube change the frame is 17'' tall, I'm 6'2'' and it's not uncomfortable to ride and a friend who is about 5'6'' took a 20 mile ride on it recently and fared okay.

Step 1: Buy a Bike

Find an old 20-inch BMX bike. I bought one on the street in Port Au Prince for $25 (I think I paid twice as much as it was worth). Try to find a bike that already has good brakes. My bike has a coaster brake in the back and cheap caliper brakes up front.

Step 2: Start Building

Find or buy tubing to build the cargo rack. I used ¾ inch x 1/16 square tubing. I bought 20' of it for $7.50, I ended up using about 25'.
Remove the cranks. Cut out the seat tube in order to weld it on top of the frame to extend the seat tube so that the bike will fit a whole person.

Step 3: Extend the Seat Tube

Cut a 12'' long piece of square tubing and slide it through the top tube down to the bottom bracket. Then slide the seat tube onto this piece.

Step 4: Seat Tube Gusset and Main Rack Supports

Cut a diagonal gusset that goes from the seat tube to the top tube in order to reinforce the seat tube.
Cut two pieces of square tubing to 56'' then clamp them to the sides of the bike frame.

Step 5: Weld

a simple 80 amp arc welder is enough for the job, I used 55-75 amps for this project. My father in law takes a turn (yes we do not have proper safety protection, yes we both got sunburned from welding this, since then I got a full face welding mask).

Step 6: Build Racks

Build front and rear racks to suit your needs. Remember to take into account the routing of brake cables, heel clearance on the rear rack, handle-bar interference when the front rack is loaded and other things I'm not thinking of.

Step 7: Build a Kickstand

build kickstand. I drilled holes just below the rear dropout. Used some random bolts to attach the kickstand to the bike. I put a small spot of weld on the belt to prevent them from loosening.The vertical pieces of the kickstand are about 12 inches long and the horizontal on the ground is 16 inches wide. The idea is that when the bike is on the kickstand the user can sell things like cold drinks or tacos from it. I used a piece of inner tube and made a hook from bailing wire to hold it up while riding.