I am back on the idea engineering. My goal is to have an auxiliary engine to help on the hills started by engaging it like the mopeds with the engine that dropped down on the front tire. I am thinking of a pulley on the shaft connecting to a rotating abrasive rod that connects to the tire. The engine would pivot on the handlebars with a lever to disengage it from the tire. The weight of the engine should be enough with a spring to keep the abrasive rod on the tire. Of course the engine would race when you went over a bump.