Keep Us Awake
"Converting mechanical motion from pedaling into electricity and then converting that electricity back to mechanical motion isn't always efficient," says Alex Roth, owner of a bicycle-powered coffee roaster and distributor in Davis, Calif. "However, with anything that works in a circular or repetitive motion, it's a great way to do things."
In the bike-centric town of Davis (home to the U.S. Bicycling Hall of Fame), Roth has devised a way to roast coffee using only human power and propane for heat. Every Tuesday night he sits on an old Schwinn that he welded into a stationary frame, and starts pedaling. The bike's fixed-gear chain is attached to an axle, which turns another fixed gear chain that goes up to a large drum located above the unit's burners and a heat shield. The drum then spins in place, tumbling the beans around the same way a clothes dryer does. "It's direct mechanical motion," says Roth.
One roast takes about 20 minutes, followed by 5 to 10 minutes of cooling. With help from friends, he usually makes about six roasts a week. "Coffee's a really dirty, ugly industry," says Roth, "and so I figure, since it doesn't grow here and we have to get it from somewhere else, once it gets here, let's try and close up as many loopholes of inefficiency and waste as possible."