i used two of these in my middle weight Wildfire in a four wheel drive setup with 8" wheels and a 1.5-1 additional reduction stage because i didn't need 19Mph but i wanted more pushing power the only thing keeping it from five stars is that the face plate needs to be a little thicker so it comes flush to the bearings as they stick out about .125 and that can be inconvenient when mounting it to something where you want minimal machining, what you can do is just make some spacers and put them in between the face and the mounting point, overall i really like it and the chain reduction system is just plain genius!!!