The idea of a two speed is nice, but you really don't need it with an electric motor. The motor is going to put out more than enough torque to drive second gear from a standstill. I didn't do a traxxas vehicle, but I did do a Monster GT and I had a similar dilemma. I acutally wound up locking the tranny into first gear. By going with a large pinion and the smallest spur, I actually get a respectable top end out of it, but it is crazy wild on the bottom. Doing back flips off of walls and trees is really easy. It suppose it gets to about 30 mph, but it gets there in a couple of seconds. I considered opening up the tranny and going with second gear, but I like it the way it is.

Another thing that concerned me was the OWB. I didn't want to have to worry about it. I drilled right through it and locked the whole up. Now I do have motor breaking and reverse. I don't worry too much about the braking heating the motor up. You'd be surprised at how little braking it is that you need to stop the truck. I think I have mine set at 20 or 30%. Really, if I had it any higher, the truck would flip over.