Just kind of brainstorming recently and wondered how possible it would be to create some type of an overdrive gear. For instance, I've downloaded the plans for the Marauder and an going to build it as my first project. But something that I thought that would be interesting to add would be a really big, oversized gear to use when going down moderate hills. Think of it.....head down a hill and when you hit your last gear (typical 21 speed setup), then throw it into the overdrive gear and really pull some speed out of it. Of course it would be useless going uphill and probably on flats. Still, I wonder how this could be accomplished?