Stacking is like falling with the bike. Sorry don't know how to explain it.
The gears inside the motor. I don't have a pic. The motor is enclosed.
Its just a theory....there are so many possibilities about this....the weight of the batteries is one of them :0)
The setup as far as how the batteries are connected to each other is better than the previous set up. TI had them sitting in a bag that a photo was taken of in this thread i think. They sit on a trailor. Don't know how to describe in more detail i am afraid.
So are you saying that the speed would be reduced with one battery or the lasting power? Like how far i would be able to go?