How to Build a Longtail Cargo Bike

We just made a longtail cargo bicycle from a second-hand Ukrainian mountain bike. It was made in Haiti with a minimum amount of tools and measuring, but it rides well. This bike has carried three adults (400 pounds total) without catastrophic failure. It is currently being tested/abused by the teenager pictured.

Find a Bike

Find a bicycle for as cheap as possible then cut the seat-stays about here, and the chain-stays just behind the bottom bracket.

Find Some Metal

Find some metal tubing. We found an old TV stand with strong tubing.

Lay It Out

Lay it out and mark the tubing for more precise cutting. Aside from the TV stand tubing we also used a tube from a women's bicycle frame to strengthen the rear end.

Build a Jig

I'm using the term "jig" very loosely. We found a piece of aluminium U-channel that was long enough and attached the frame to it in order to hold the frame in a straight line.

Wire It Up

We used bailing wire to hold everything in place. Clamps would work better.

Measure

We used string and a ruler and a nail on the end of the string to build a plumb-bob. The goal is keep everything as straight as possible.

Measure More

Measure some more and cross your fingers.

Find a Welder

We used this cheap stick welder and used 50-75 amps for all of the welding.

Weld

tack weld then measure/eyeball everything for alignment and weld some more.

Weld

Weld some more.

Paint It and Name It

We chose the name Cheval which means horse in Haitian Creole. Choose a font, make a stencil and paint it on.

Admire It

Our western style font is awesome.

Make a Head-badge

Every bicycle needs a head-badge.

The Whole Thing

We left out a lot of small steps because we used mostly found items and we lack some basic tools but hopefully this is enough information to get you started. A few things not previously mentioned are the board above the back wheel. To attach the board we pre-drilled holes through the wood and metal and then put nails through which we bent over underneath. We used fork blades welded to a metal tube as a support going from the end of the board to the rear axle. We added an extra chain to make it long enough but we are not using the large chain ring on the front of the bike so we made the chain long enough for the middle chain ring. We also welded foot pegs on the rear chain stays.
Most new rear derailleur cables should be long enough to reach, I didn't buy a new one but used a small bolt and nut to join a scrap of cable to the original to make it long enough. I did buy a new brake cable and it also works fine.

Ride It

We are in Haiti so for $2.50 we bought the woven pannier which are made for a horse or mule. It looks great and works. The bike still needs a good kickstand.