This would be my first bike project, and the first welding I would be doing ever. I started out with the all important research. I spent time online looking for resources. Pictures of bikes from the Netherlands where these are common became an inspiration. I wanted something old looking but at my friends recommendation knew that I would need gears. I found Tom's Cargo Bikes website and used his basic outline to build my own.
Now lets get started!
Note: When I made this bike I did not take nearly enough pictures so I have added some when the bike was finished.
Step 1: Gather Your Parts Bikes
The kids bike was found on Craigslist for $15. It was an inexpensive boys bike made of steel. Since you only use the front wheel and steering tube most bikes will do. I avoided bikes with front suspension because on these small kids bikes it's not worth the weight. I also made sure the bike had a rear coaster brake so I could use the sprocket for my cable steering.
In addition to the two bikes you will need steel tubing in various sizes. Some hardware from a hardware store and time. My finished bike is 7'11" from end to end so your raw material measurements may be different depending on your finished length.
1 Adult donor bike
1 Kids donor bike with 16 inch wheels.
2 ~5 foot lengths of 3/4" tubing.
~5 feet 1/2" tubing for the basket frame and kickstand.
~2 feet for kickstand tube
~5 feet for middle frame.
~2 feet for steering tube extension.
~2 feet for steering shaft extension.
~4 feet bar stock for basket support. 1/2" wide.
~2 feet bar stock for kickstand, approximately 2" wide.
Lengths are estimates. Your's will be different depending on your chosen length, donor bikes, etc.
4 pulleys from the hardware store.
~6 feet of stainless steel airline cable.
8 ferrules to fit the airline cable. 5/16ths I think but buy the thickest that will go through your pulleys and the bike chain.
2 eye-eye turnbuckles.
Length of bike chain from kids donor bike.
2 sprockets from wheels with coaster brakes.
Basket materials? Wood, plastic, old street sign. Whatever you want to work with.
Screen door spring for the kickstand.
Step 2: Where to Start?
Starting with the kids bike I used an angle grinder to cut the front of the bike off. I did this about 5 inches from the neck. Your donor bike geometry will determine where you cut. I left as much as I could on while keeping the curve of the cargo bikes neck intact. At this time I also removed the rear sprocket from the bikes rear wheel, and the chain. Both for use on the steering system. Keep the rest of the bike around until the end of your project, you never know when you will need a little bit of metal.
If your kids bike has a top and bottom tube you will want to notch the underside of the top tube and bend it down parallel to the bottom tube. My donor bike just had a single fat tube so this was not necessary.
On the adult bike I removed the front wheel, forks, steering, cabling, and set them all aside.
I wish I had taken more photos during the build but I did not. I highly recommend you visit Tom's site and check out his step by step guide. It was my starting point and is very will documented. Go check it out now!
First step was to weld the "snorkel" tub onto the main bikes steering tube. After removing the bearing cups you get a piece about 2 feet long that just slips over the head tube. Cut it so it slides right up to where the top tube attaches and weld it on.
Second you can take the 3/4" pipe and bend it to create the main body of the bike extension. The front bend angle will depend on the shape of your kids bike and how much you left on it. My version has two bends instead of the one in Tom's instructions. I did this so I could maximize my cargo space by creating a more vertical transition. Also instead of butting the main tubes against the bottom bracket I mounted them on top of the bracket. This took a little trimming on the tubes so the chain would clear when peddling.
After securing the two main tubes I added one more, larger tube, right down the middle for extra support and to eliminate flexing. This tube got shoved up inside what was left of the kids bike tube and welded in place. The other end butted up against the snorkel. Welding was done to secure the snorkel to all three tubes.
My picture also shows the first steering mechanism in place. The original design called for a tie rod steering system, like the one on Tom's bike and most other cargo bikes. It is easy and trouble free but in my case not easy enough. Mine flopped around and looked bad and after fighting with it for several days I threw it out and made my own design.
Step 3: Time to Make It Stand on Its Own.
For my kickstand I used about 3 feet of the 1/2" pipe for the legs and a short length larger of pipe for the tube. The stop was made from about 1.5' of bar stock, 2 inches wide. You start by bending the 1/2" pipe on one side to create the first leg, then insert the leg pipe into the bigger pipe and bend the second leg. If you bend both legs first you won't be able to put the kickstand into the tube. It would also be a good idea to drill a hole in the kickstand leg and attach an eye bolt. This is for the return spring. I did not do this in advance and have yet to do it so my spring just slides along the stand. It works but in ain't pretty.
Next take the bar stock and weld it to the large tube. The length needs to be longer than the big tube, just enough to keep the kickstand leg from swinging too far. Now with this in place weld the kickstand assembly to the bike frame right in front of the steering tube. It is good to have your steering sprocket in place so you can be sure your kickstand clears it.
For added stability and so the kickstand does not sink into dirt you can add small feet to the bottom of the legs. I just used a few inches of 1/2 inch tube.
In the second picture you can see my return spring. It is just attached with bolts to my basket and loops around the leg of the kickstand. The spring is just a cheap screen door spring.
Step 4: Super Slick Cable Steering Part 1.
To get started you need to extend your existing steering column. Take the front forks that you removed from the big bike and cut them in half between where the threads end and the forks begin. Now cut the forks down so you just have enough of them to weld the small rear sprocket to. Next take your extension pipe and cut it to length. You need to measure your new head tube and do that math so your finished product will fit. I also removed the headset and bearing cups before I did this. In so doing I destroyed one but these are easy to replace and cheap to boot.
After you measure, re-measure, and measure again for good measure assemble the new steering column and weld it together. From top to bottom it will be: Threaded section-->Extension pipe-->Top of forks-->Sprocket. Don't forget to put the bearing guides back on during assembly.
Because of the angle of the head tube the bottom sprocket will be angled up a bit. You may want to compensate by cutting the forks down at an angle. I just eyeballed it and got lucky. I think I only had to fix it once. You want to leave some angle on their because the path to the first pulley is not horizontal.
Step 5: Super Slick Steering Part 2
For the steering cable hardware I went to the local hardware store and for about $20 picked up everything I thought I would need. I found steel braided cable, 4 pulleys, 8 ferrules, and 2 turnbuckles.
I needed to make two 90 degree turns with the cable to get it from the front fork to the bottom of the steering. To do this I used inexpensive pulleys from the hardware store. My pulley wheels were riveted to their covers so I started by drilling out the rivets. I then found bolts long enough to pass through the pulley and through a hole drilled in the 3/4" pipe. I attached two at the top turn and two at the bottom. I used nuts with built in lock washers because I did not have much space to work with. Don't tighten too tight or your pulley won't spin.
I then assembled the cable assembly in two pieces, a front and a back. Both consisted of a length of bike chain in the middle where it would pass around the sprocket. Attached to the chain was steel cable. I just put a ferrule on the cable, passed it through the last link, folded it over and passed it back through the ferrule. I then beat the ferrule flat to hold it all together.
To the other end of the cable I attached an eye bolt that fit the turnbuckle. Using the turnbuckle allows me to tighten the cable assembly on both sides. If it was not there I would have to get the cable length exactly right and for me that is impossible. After finishing this and tightening it up I found that the front wheel and the handle bars did not line up. The easiest thing for me to do was to loosen the stem and adjust the handle bars so everything lines up.
Congratulations! You have super slick steering that elicits endless double takes from people that see you go by.
Step 6: Building the Basket Support Frame
I bent two pieces of 1/2" pipe and made my rough rectangle with the front narrower than the rear. Simply weld this in place and then add bar stock for supports. The important thing is to provide a stable platform to build on later. In most cases this frame will be covered later so it need not be pretty.
Step 7: Final Bits and Paint
This part sucks but it makes the most difference in how your final bike looks so take your time. I had been using a wire wheel on my angel grinder to remove paint from most of the components so there was not much left at this point. Any parts small enough went into the sand blaster. Lots and lots for grinding on my welds made them look smoother. On the neck of the bike I then used Bondo filler to really smooth things out. When I was satisfied I washed and dried it really good and moved it into the paint booth.
I then sprayed it with a gray primer. I think I used 2 cans on it for several coats. The final color was dark green and I gave it as many coats as I could with the 2-3 cans of paint I had. Follow the instructions for drying for best results. Also don't buy the cheapest spray paint you can buy, it sucks. Good spray paint covers well and dries fast. The cheap stuff will run easy and make more work for you in the end. The fenders got several coats of a lighter green and the steering components got a nice gloss black.
Step 8: Reassembly
I then added the single most expensive part of this project, the front white wall tire. $32. When I put the crank back on I quickly found that my chain was hitting the extension tubes so I needed to take it back apart and cut a slot in it. The picture is shown earlier on. The last pick is at the bike shop using their crank wrench to remove the cranks. I still need bike tools but having a shop across the street was really handy.
Next one I make will have disk brakes. My bike has cantilever brakes on the rear that work OK and nothing on the front. I originally tried to use the U brakes from the kids bike but they hit the fender and no amount of bending would help. Style won out over safety and the front brakes were removed and replaced with a spelling B trophy I found at a yard sale.
The last touch was a vintage headlight that I retrofitted with an LED flashlight and painted to match the bike. Batteries for the lights are hidden in the basket.
Step 9: The Temporary Basket Becomes Not So Temporary.
I had in my possession collapsible plastic crates for carrying artichokes. I got these for $1 each at a yard sale and figured I could use them for under bed storage of shoes. Instead they would become my "temporary" bike basket. I took two of them and cut one of the long sides off each. I then fitted them together, cutting more as needed to make my basket. U bolts held them to the support frame and water heater strap was used to hold the sides together. Presto! instant basket and the sides could still fold down to make a flatbed.
Step 10: Finished!
Eventually I made the cover for the basket. Another yard sale delivered a bunch of valence trim pieces. I was able to cut these down and make a cover that buttons in the back. It goes on quick and has the reinforced corners, flaps overlap in the basket to cover the seating area and it looks great. My temporary basket became officially permanent.
I have been using this bike several times a week for the last 3 years now and it is still my favorite. I can load it down with everything I need and get where I need to go. I recently upgraded the cable on the steering to thicker airline cable. The old stuff has started to fray but never failed. Riding the bike is easy and fun and always gets positive comments.
Total cost was about $125. The cost was kept down by using recycled metal, and cheap or free donor bikes. As for the time it took I would have to say lots. It was a learning process the whole way through and so I think every weld got re welded at least once. It was a wonderful experience to build and that makes it more satisfying to ride.
Thank you for checking out my bike and please vote for me so I can get my own bike tools.