well the reason the moby takes hill is because the CVT, or variator, it has which is the belt that you see on the left side. variator engines pull a lot better and put power to the ground more efficiently over your standard chain driven motor. Gearing on variators, moby's in particular is not going to be anywhere the same as your puch, they opperate on different principles, honestly, unless anyones knows what they are doing you should not really alter the gearing on a moby. All peds follow the same principle of the fact that bigger in front, smaller in back=more top end speed
vice versa=more lowend. If you wanted more pull on your mag you should switch to like a 14/40 or like 16/45, but it wont be that fast on the flats.