ORIGINAL: gs-stormracer
dont you mean 12 t spure gear? not 122t!
No, spur gears are the big gear on the tranny. The pinion gear is the one on the motor's shaft.
As far as a recommendation, do you happen to have the manual that came with the Pro 2? Do you have a LHS? If neither of those, you can probably get an answer out of the guys in the on-road forum, since they're bound to have a Pro 2.