Okay, first off somewhere I read that the planetary reduction on this kit had a 4.91-to-1 gear down ratio. This did not sound right to me. Picture on the first page of this thread shows a simple single stage planetary reduction unit with an input sun gear will 11-teeth and three planet gears with 22-teeth each. Its difficult to count the ring gears teeth but careful scrutiny of the image and counting gives me a 55-teeth ring gear which mathematically makes sense, because on a simple planetary gearing system without complex two stage planets the following formula is used:
(sun gear teeth count) + 2 x (planet gear teeth count) = (ring gear teeth count)
Thus with the input being the sun gear and the output being the planet carrier and the ring gear being fixed the reduction ratio must be 6-to-1
(ring gear teeth count) / (sun gear teeth count) + 1 = (reduction ratio)
I think someone made two mistakes in their math. First they forgot that with a planetary reduction gear box with a sun gear input and planetary carrier output and fixed ring gear you get a full extra rotation of "bonus" reduction due to the over-running orbits the planets make. Accounting for an incorrect 5-to-1 vs. correct 6-to-1 calculation. And then by miscounting the ring gear teeth by one less, AKA counting 54 rather then 55 teeth on the ring gear that would give them an incorrect reduction of 4.909090909090909---> repeating pattern which rounds down to a two decimal (incorrect) result of a 4.91-to-1 reduction ratio:
Long story short we have exactly a 6-to-1 reduction ratio in the planetary gear box on the motor. Which considering the motors free spinning no-load output after the gear box is specified as follows on the Sick Bike Parts (.com) (a U.S. seller offering just the motor itself domestically for those so desiring):
36v e-bike pack = 450-rpm
48v e-bike pack = 600-rpm
60v e-bike pack = 750-rpm
72v e-bike pack = 900-rpm
Well depending on exactly what was the actual pack voltage they used the Kv of the motor itself is going to be somewhere around 75-Kv. The "small block" motor the the Lightening Rods Kit uses and which is used on the GNG kits is fairly well established to be around 67-Kv or so. Might be the exact same motor assuming someone slighlty inflated their output RPMs by running the motor using a pack that was hot off the charger and at higher then rated nominal voltage. Or it could be a similar motor that has just a very slightly higher Kv rating maybe just one turn less on its windings or such.
For those not convinced that you get an extra full turn of gear reduction then would be initially assumed out of a planetary gear reduction box like this motor uses I threw together some simplified 2D-CAD model frames and assembled them into animated .gif files to demonstrate. Continuous running version first and then slow motion version so you can more easily count the rotations by the timing marks with a couple second pause at TDC when all the timing marks line up. As you can see it takes 6 full turns of the 11-t sun gear that is the input from the motor to get a single full rotation output from the planet gear carrier (represented by the purple triangle). I used lobe cog gears simply because they are quicker and easier to draw then toothed gears but the principle holds true regardless:
So I hate them and put them in a corner 8) 
