Lawnmower derbies. Devon, Penn., is where youll find the home of this exclusive event. Kids forced to mow lawns struck out against the tedium by organizing speed contests. They set up various classes to equalize the competition among the various sizes and types of mowers. Each year, at the starting signal, operators dash to their mowers, start them and pilot the spluttering machines full speed down a paved street lined with cheering spectators.