Stock gearing is 24/39 and as far as I am concerned, its a pretty good setup for all around purposes. Being the XCR8 motor already has tons of power and torque, dropping gearing down lower would only makes u get less mpg, more track spins. Unless youre running 136 long track version or longer and plenty of tractions, then I can see you might wanna playing with the gearing. Like others above, depending on your riding style and what you want your sled to do. WL
The AFTERBURNER!!!