Even though it’s DC, this generator can be used to power AC appliances such as compact fluorescent lamps, tube fluorescent lamps, sewing machines, blenders, coffee grinders, food processors, juicers etc.
The appliances can be found at resale shops for less than $10. If it works it will not damage the appliance (famous last words). We caution not to try any AC appliance that is worth more than $10. You can put a fuse on the appliance to protect it. The only appliance destroyed so far was a small coffee grinder. We were pedaling very fast (producing around 200 volts DC) when we turned on the grinder. The lesson learned was to turn on the load (the appliance) before starting to pedal.
We use McMillan Motors but from Delta broken treadmills but they are increasingly hard to find. Try your local scrapyard for generators. You will recognize the a DC permanent magnet motor because a paper clip will be attracted to it and there are usually only two wires coming from it as opposed to several for an AC motor.
The V-belt and sheave (pulley) are from Grainger. You may need to wrap aluminum flashing on the shaft for a tighter fit. Take the generator with you when you go to Grainger to fit the sheave and pulley.
Use a small V-belt sheave. The smaller the sheave the higher the rpm and voltage. In either case you will need to flatten the shaft slightly with a file or grinder for the sheave set screw.
The v-belt should be around 88″ to go around a 26″ wheel and the pulley. The formula is pi times the wheel diameter or about 3.2 x 26 = 83″ plus room for the sheave (88″ or more).
An inexpensive bike trainer is used to get the bike off the ground. There are bike trainers for as little as $50 available.