Introduction: How to Build a Longtail Cargo Bike

Picture of 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.

Step 1: Find a Bike

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

Step 2: Find Some Metal

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

Step 3: Lay It Out

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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.

Step 4: Build a Jig

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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.

Step 5: Wire It Up

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

Step 6: Measure

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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.

Step 7: Measure More

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Measure some more and cross your fingers.

Step 8: Find a Welder

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

Step 9: Weld

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

Step 10: Weld

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Weld some more.  

Step 11: Paint It and Name It

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

Step 12: Admire It

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Our western style font is awesome. 

Step 13: Make a Head-badge

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Every bicycle needs a head-badge.

Step 14: The Whole Thing

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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.

Step 15: Ride It

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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.

Comments

MadsA2 (author)2015-10-12

Great instructions and a big inspiration! I can't weld so I extended a mountainbike frame with wood, epoxy and carbon fiber tow. You can watch a short video of how I made it here https://www.youtube.com/watch?v=_gss4TuZqr8 or by serching for "DIY longtail cargobike mads" on youtube.

kermitg made it! (author)2015-02-12

Having done this my self I would recommend extending the seat stays and chain stays, as with this method you can use thinner tubing and avoid welding on the seat tube, which if a melt through occurs will cause problems fitting the saddle.

I used this (above) method, inserting thicker tubes, and it works fine. I enjoying riding the bikes and it a very useful thing to have.

If you would like to read about my experience then Google:

"dorky thorpy longtail cargo bike"

MountainMommaC (author)2012-07-16

Hey, thanks for the design!

I want to pick your brain a little bit--I pretty much need this bike, plus platforms and a heavy-duty kickstand so it won't be exactly the same...

First, do you have any concept of how much extra weight this put on the bike? i.e. are we talking five pounds or fifteen?

Second, have you tried making a sturdy kickstand for it? and if you have, what are the chances of you putting THOSE plans up too?

Thanks again :-)

depp.ben (author)MountainMommaC2012-08-09

Hi, I didn't add a kickstand. I don't have this bike anymore so I can't weigh the bike but I'm guessing this modification added 10 pounds to the bike. Goodluck.

harknirf (author)2009-12-31

 just built a bike like this based on this instructable, even used the same welding machine.  turned out great!  Thanks for the write-up/inspiration.

depp.ben (author)harknirf2010-05-07

That's awesome, I'm happy to hear it.

laughingcoyote (author)2010-03-18

Don't let that 'chicken' into my coop! The cox comb doesn't fool me: the beak and head belong to a raptor. A great bike!

milly0345 (author)2009-12-20

cover those legs and arms not only against the sparks.I have the scars to prove that but the UV light  and use a mask

stephenniall (author)milly03452010-02-15

i was reading about a guy who was restoring his car and used a welder for prolonged periods (a few minutes at a time within like a few hours) he ended with a tan with tan lines the size of his goggles!

chadeau (author)2009-12-01

He said 'hole' ! lol

Koosie (author)2009-12-01

Awesome, that's like a pick-up-bike!

gmoon (author)2009-11-30

Great build--nice chickenhead welding mask, too.

About This Instructable

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Bio: I'm working in Haiti and living in the lovely city of Port Au Prince.
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