Maybe u picked the wrong moped to do with a rear hub motor. Hobbits as well as vespas have a "subframe" and not a rear swingarm. The fulcrum is either above the engine as in a Vespa or part of the case of the engine ,Hobbit. So now you gotta add something to the sub that defines the pivot and has strengthened the sub like the Hobbit sub does. I think a Puch would be immensely easier to make which is why guys post e mopeds that look like a magnum. But good luck.