hi every1,
jus wondering, wats "roll out"...ive seen it mentioned a few times in different threads and have no idea of wat it means...seems important though...is this pertaining to both nitro and electric cars?
thanks for any feedback and of any useful explaination!

You use rollout if you run foam tires.

(Tire diameter x 3.14) / (Spur/pinion x internal gear ratio)

It's a calculation that tells you how far the car moves with 1 revolution of the motor. You can also use a tape measure and just turn the motor 6 knotches(1 revolution) and you'll get the same rollout(just take up the slack in the drivetrain when you measure).

check out:
http://www.actmcrc.org.au/technical.htm

also has a roll out calculator, and a print function is ont he way

Its mainly for Electrics I think.