Originally Posted by carpediemracing

There was a kilo bike that had a chain on the left side as well as the right. I think it used a lower gear on the left and wasn't tightened so that as you accelerated it unscrewed. Somehow it worked such that after that the right side chain engaged properly, a higher gear, so the rider could accelerate hard and then finish well. I'm pretty sure it got banned immediately.

There was also a fixed gear road bike (derailleurs above and below the freewheel, apparently that makes a fixed gear derailleur bike work) which drove a BB shaped like a crankshaft. A piston pressurized the three main tubes. An extra shift lever acted as the valve to either store or release energy. When released the pressure drove the piston. The inventor did some nutty 10 mile TT time without really being a cyclist, like 25 min, aka 25 mph. Store on downhills or easy sections, release on hills.