hey thanks so much for the explanation BrianG. Kinda hard to swallow all that. So ur saying with my setup of the mm and 9XL ill be needing a UBEC to be safe? But I think all ill be using will be a 7.2v 2s 4000mah batt's Anyway wats the diff with the Feigao 540C 9XL Brushless Motors & a Feigao/Nemesis/Wanderer "9XL" Brushless Motor? And i should get a gearing of 17/66 32 pitch ?