Hey, anyone ahd luck with these motors for MTB's? It seems the only place I can find them is on ebay, and i'm super sketchy about it. I was reading the feedback on the two biggest sellers, the negatives are pretty bad. I'm really interested in these for the days when i'm tired, or just lazy Anyone bought one? And for the record, I want one of the motrs that mount inside the front triangle, with the gas tank on the top tube.