This instructable is on how to make suspenders of the traditional type (using buttons to attach them to your pants instead of clips) out of old bike tubes, using a minimum of tools or fancy supplies. It's kind of a quick-n-dirty approach emphasizing simplicity rather than craftsmanship but they end up looking pretty cool and I've gotten lots of compliments on them. If you don't have buttons on your pants for attaching suspenders they're pretty easy to add and I personally prefer suspenders to belts.
Step 1: What You Need
In order to make your exciting new suspenders you will need:
Two old bike tubes
A pair of scissors
A bike tube repair kit (or rather the glue in it)
Sandpaper (optional but highly recommended)
Opening up the tube repair kit you will most likely find one or two tire levers, a few rubber patches, a tube buffer (either a little metal grater thingy or a tiny patch of sandpaper) and, more importantly, a tube of glue. The glue is what we're looking for. You can use the tube buffer to rough up the tubes but it's going to be a pain so I would suggest using a larger piece of sandpaper.
Step 2: Cutting and Glueing Part 1
Cut one of your tubes into two pieces of equal length, make sure to cut off the part with the valve. Out of the other tube, cut three pieces about 16cm (6 1/2") long. Cut a sixth piece shorter than your long ones but longer than your short ones. You're probably going to cut off most of this piece in the next step so exact length isn't very important but it's better to be safe than sorry so don't cut it too short!
Next, cut up your short pieces lengthwise (see picture #2) and rough 'em up on the inside using the sandpaper. You will want to rough up more or less the entire surface so here's where it's going to be painful if you chose to stick with the little metal grater. Goo 'em up with glue (make sure to read the safety instructions first!), fold them over so that they make little squares (see picture #3) and put them under something heavy. If you're doing this in your living room you might want to protect your floor with some newspapers, just in case you got a little carried away with the goo part.
Step 3: Cutting and Glueing Part 2
Rough up one of the ends on each of your two long pieces (all the way around) and glue them together as shown in picture #1. Place under something heavy while the glue hardens. Pull one end of your shorter piece inside out in order to rough up the inside of the tube (see picture #2). When your first assembly has hardened, put a bit of glue in the shorter tube (you can spread the glue around the inside of the tube by pinching and rolling the tube between your fingers) and glue the whole thing together as shown in picture #3, don't forget to weigh it down.
Step 4: Some More Cutting...
While you're waiting for your joint to harden, retrieve your little squares and cut them to shape. The general shape you're going for is bulb/garlic. You can get just as fancy as you want to here, just make sure to leave a piece at the top that can go into your tubes and leave some room around the button slits so that they don't tear. And yes, cut slits for the buttons. While you're at it, rough up the tops (both sides) with sandpaper as shown in picture #2.
Step 5: Fitting and Final Assembly!
Now, you will need to cut down the tubes to proper length. This is a whole lot easier if you have someone to help you as you will need to determine at what height you want your pants to be, where on your back you want the joint and how much you will have to compensate for the overlap between your tubes and your "bulbs" (the tops of the bulbs go into the tubes), all at the same time. My recommendation is to put everything on (by that I mean wearing it) and then have someone to help you with keeping everything in place and cutting the tubes. Once you have your tubes cut, rough up the insides of the ends as shown in step 3 and glue your flappy bulb thingies into your tubes. As before, put the whole thing under something heavy while the glue hardens. Done! Wear it!