Introduction: Sprocket & Innertube Belt
Comfortable, functional, and entirely badass belt made from recycled bike parts.
The original belt in these photos was made by my friend Fjord, and he deserves credit for the idea and for making a number of these belts. He used thin strips of innertube rubber to attach the pieces of chain to the belt, though, and after a year of heavy wear those started to give out -- hence the repair work I'm doing now, and the photos for this instructable. The punched holes for fastening the belt are also starting to show wear, but I haven't figured out how to fix that yet. Let me know if you have any ideas!
Step 1: Gather Supplies.
What you need:
- old bike innertube(s)
- clean bike chain & chainbreaker tool
- old bike sprocket, ~2" ID
- 4 small flathead screws, with matching tiny nuts
- ~2 yd thin elastic cord (I had a fair bit left over.)
- heavy-duty holepunch
- measuring tape
Step 2: Break Down Your Bike Parts.
For the base of the belt, take one innertube and cut it 2-3" past the valve stem. You should now have a long strip of tubing with the valve stem close to one end. Measure around your waist where the belt will sit, then add 8-10" to that measurement for the tail of the belt -- this measurement is the total desired length for the belt. On mine, the total belt length is 36", with an extra 2" of tubing past the valve stem to fold over for the belt buckle.
Lay your proto-belt out flat, then measure out the length you just calculated, starting at the valve stem. Mark and cut the tubing to that length. (Note: You're ignoring the 2-3" of tubing on the other side of the valve stem because that's going to be folded over later.)
From the tubing you have left-over, cut a 1"-wide section. This will be the...um...the little loop that you thread the tail of the belt through after it goes through the buckle. (Is there a word for that? If I poked the internet to dig up the proper word for that, would anyone know what I was talking about?)
For the sprocket, you may be able to find a lone sprocket wandering around, or you may have to detach it from a cassette and clean it up. You want one where the inner diameter is slightly smaller than the length of the valve stem.
For the bike chain bits, you can start with an old, worn, greasy chain and clean it up, or just buy a length of new chain -- less cleaning, more shiny! Since Fjord did all this work long before these pictures were taken, I don't have photos of the process. The idea is to take the chainbreaker tool, disassemble the chain, and separate out the flat top & bottom pieces of the chain. You'll then stitch the flat top & bottom pieces onto the belt with strips of rubber or elastic cord. Design your pattern first to figure out how many chain-bits you need; my belt has two rows with 22 chain-bits in each row, so 44 flat figure-8 chain-bits in total.
Step 3: Make the Belt Buckle.
The belt buckle consists of the valve stem and sprocket, as shown. The 1"-wide section of tubing is attached close to the buckle, using the same bolts that fasten down the end of the overlapped tubing.
First, decide which side of the sprocket should be the front of the belt buckle. Next, take the valve-stem end of the tube, thread the short end through your sprocket from front-side to back-side, and fold the short end over so that it overlaps the longer end. The overlap should be on the back of the belt, and the valve stem should lay across the front side of the sprocket.
Mark four points on the overlap for the tiny bolts that will fasten the sprocket in place, hold down the overlapped section of tubing, and attach the loop that holds the tail of the belt. Mark the first two points at the edges of the tubing close to the sprocket, so that it will be held tightly; mark the next two at the edges of the tubing close to the end of the overlap.
Using the heavy-duty punch, punch four small holes (diameter slightly smaller than that of your tiny, tiny bolts) at the points you've marked. Also mark & punch two holes through one side of the 1"-wide capture loop.
Push the first two bolts through the holes closest to the sprocket, from the front to the back of the belt, then thread on the nuts and tighten down. (If you had a riveting tool, I'll bet you could substitute little rivets for these nuts & bolts. Personally, I like the tiny tiny bolts.) Push the second two bolts through the holes in the capture loop and the matching holes in the overlapped section of the belt, thread on the nuts, tighten down. Wheeee belt buckle!
Step 4: Punch More Holes.
You now have an almost-wearable belt; it's time to size it properly. Put the belt on as you're going to wear it normally, then thread the tail of the belt through the buckle. Tighten it enough that it'll hold your pants up while still being comfortable, then mark the point on the tail of the belt where it overlaps the base of the valve stem.
Flatten the tubing out so that it's all in line with the flattened fold at the belt buckle; remember, you want the holes on your belt to line up with the valve stem without twisting the innertube around. Punch a hole (diameter slightly larger than the diameter of the valve stem) at the point you've marked. Since people tend to change circumference sometimes, mark out a few more holes, with 1" spacing between each hole and the next. Mine's got eight holes, which leaves me a 5-6" tail on the end of the belt most of the time.
Your belt should now be entirely wearable, if not quite as awesome as it could be. (I'm getting to that part.) Try it on, dance around, show it off, make sure it's comfortable.
Step 5: Yet More Hole-punching!
You've now got a long strip of bike innertube with a row of holes at one end and a badass belt buckle at the other. The middle part, however, is plain. Boring. The double row of bike-chain bits keeps the tubing flat (like a regular belt) and adds subtle shiny recycled awesomeness.
Flatten out the tubing again. Mark two parallel lines down the length of the belt, with whatever spacing you want between rows of bike-chain bits. On my belt, there are 22 pieces of chain-bits in each row. The holes in each figure-8-shaped chain-bit are 0.5" apart on center, and they're spaced so that there's 0.5" from the center of a hole in one chain-bit to the center of the hole in the next one over. The chain-bits alternate between the flat (shiny) side and the not-flat (grungier) side, and are laid out end-to-end.
You could use this same pattern, or lay the chain-bits vertically or diagonally instead of horizontally, use different spacing, or stitch on entirely different beads/hardware/etc for decoration. Get creative with it, make it your own thing. Remember, though, if you're stitching chain-bits on, you'll need to punch a hole directly underneath each of the two holes on the figure-8 chain-bit, so your pattern will be made up of pairs of holes set a fixed width (0.5", in this case) apart.
Step 6: Stitch on the Bike-chain Bits.
This belt was originally made using strips of innertube rubber for the stitching. To use that method, slice two ~3' x 1/8" strips from another innertube and substitute that for the elastic cord in these instructions. Be aware that it's likely to wear out a good deal faster.
When repairing my belt, I pulled out the broken pieces of the rubber strips and replaced it with bright-blue elastic cord. I improvised a "needle" by attaching a short bit of twisted wire to the end of the cord. To start stitching, tie a knot in one end of the cord and pull it through the first hole in the belt-rubber such that the knot stays on the back side of the belt. Then thread it through the first hole in your figure-8 chain bit, through the second hole on the chain bit, and through the second hole in the belt-rubber. Repeat for all of the chain bits in that row of the pattern you've designed.
For each row, I started out leaving the stitching a little loose, with an extra length of elastic cord after the last hole. After finishing the stitching on both rows, I went back through and tightened it down, making sure that the cord lay as flat as possible without bunching up the belt-rubber. Once the stitching is adjusted, I pulled the unknotted end through a little bit (just enough to tie the knot in the right place, so the knot holds the cord without causing the belt to bunch up) and tied a tight knot. Repeat that to tie off your other rows / cords.
Finally, my belt has a couple of large stitches closing the tube at the tail end of the belt. You could do this with a short length of the cut-rubber strip, a bit of elastic cord, or you could stitch it down with a needle & thread.
Step 7: Done!
The one tricky bit with the belt I've got is that the teeth on the sprocket are a bit sharp and pokey sometimes; that should be fixable with a little judicious filing & smoothing. Other than that, it's comfortable, strong, stretchy. Plus it's got shiny bits, it gets double-takes and comments, and it holds my pants up. Win!
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