My buddy and I found directions for something like this back in the late 80’s in popular mechanics...Ours was much more crude, but only cost us for extra cable and 2 pieces of electrical conduit...basically flip the bike upside down...flip fork 180 degrees, flip entire crank unit, add conduit for seat post and steering extensions and then figure out how to ride it...easy to have front wheel come up, so beware if you get energetic about building one..lol