Originally Posted by
the incubus
rcman,
Depends on the spur you're running, which depends on the track you're driving on. I've found an 81 spur with a 25 pinion works well for most applications. If I need more low end bite I go up a tooth or 2 on my pinion, more high end, go down 1 or 2 teeth on my pinion.
won't know what spur I have until its in hand, track is an outdoor mid-sized (big enough for 1/8, but still manageable for 1/10) tire of choice is SS AKA Impacts