My $30 clone of a $2388 clock. http://www.wired.com/gadgetlab/2009/11/confusing-bike-chain-clock-runs-backwards-and-forwards/ Mine is bigger (it is 3 feet long) and it reads more intuitively. I don't like the numbers. They are fat and wooden, but I couldn't find a source for ~3" cheap metal numbers. * 1rph motor: $6 * 6' #40 chain: $10 (with 4' to spare) * Sprockets: $8 * Numbers: $6
