[johnrobholmes]

You can also figure rollout in relation to the tire. Just figure out the circumference of the tire, then you know that it takes 28 motor rotations to travel 17.27" on 5.5" tires. We can assume no ballooning for now.

Said another way, it takes 19.44 revolutions of the motor to roll one foot.

So assuming 4v/cell under load we have 2716 feet/ minute speed. Close to 1/2 mile per minute or 30mph. Seems very reasonable gearing to me.


Running 40 series tires with 7" od we can just take that 30mph and multiply by (7"/5.5") to get 38mph. Still very reasonable.