The clamp makes life easier, not harder.
One screw to remove the whole motor for maintenance etc and you don't loose your meshing for it. You do not need to remove the undertray really, just unhook it from rear bumper and it will flex easily giving you access to the screws.
I can't see how often you need to change pinions, especially when you run brushless and you are gearing only for speed. Either way it takes no time to change a pinion. Firstly you don't need to remove the motor. So all you have to do is undo the pinion and take off, push the undertray back and loosen the two meshing screws, put new pinion on, mesh and tighten up two screws again. It takes 30 seconds max.
__________________
Jason Moller
|