I'm still thinking a three wheeled bike like the following is the best solution:




Now try to imagine some type of "can crushing" gizmo added to this bike. I'm wondering how much power it would take to crush a can. Actually, IdahoScrapper, you might be onto something. Let's say that we carry a few large capacitors on the bike and as you pedal, you generate "charging" voltage\current that is stored in the large capacitors. Then when it reaches a certain stored energy level, it triggers the release thru a crushing motion.