Gearing an 8XL
 

I have the Robinson Racing Double Disc set-up that came with a 72 tooth spur. My E-Maxx weighs about 12 pounds and I am using 7 cell IB 4200 batteries. Is there a low enough pinion that can be used to run an 8XL and 9920 and not get hot? I want to stay in the 40 mph range.

I would try a 18 tooth for the 14 cells if you running that count.