The gearing will affect voltage sag, since you will pull more amps, which in turn, is the batteries performance. If a battery sags too much, you will either over discharge your battery frequently and shorten your range. A big factor on SAG is amp draw, especially in amp draw in relation to the max continuous amps a cell can take. You will sag will grow exponentially as you approach and surpass the max continuous amps the cell can take. One of the simplest solutions to SAG is lipos. They are more dangerous, but they usually handle far more amps and as a result, sag much less. Since evolve went to li-ion, which is the safer direction, they will have to deal with sag, especially in the small configuration they use in the GT.
Basically, you can ignore those motor ratings for the most part. Your main concern in a motor should be stator size, magnet fill, and copper fill. Since nobody likes to hand these numbers out freely (beside hummie), it’s anyones guess as to whose motor is more powerful. I would say based on what I know about the 2 motors, I believe the r-spec is a far superior motor in terms of power.
I run 4 motors, and I have yet to pull more than 1000 watts on the entire system… I ride up hills well over 20% at speeds about 18 mph, and I still can’t pull more than 1000 watts. And theres no standard for getting these numbers, just like there’s no standard for battery range. Everybody says they get 20, 25, 30, or even 35 miles in range. But what they don’t tell you is that’s going down hill and flats with wind pushing your back, and you must weight 120 pounds. You also like to ride at 12 mph with weak acceleration.
From the testing I have done so far, the biggest factors I’ve found weight and environment, but especially weight.
If your new to electric skateboards, I would recommend building your own, and over specing everything. Vendors often exaggerate numbers to compete.
Currently, there’s no board on the market that met my need for both speed and torque, so I built my own. Now I have more power than the GT, Raptor, or any other board on the market for under 2k. And soon, I’ll have hopefully at least twice the power and an even higher top speed.