It's possible to solve this with math. Multiply your gear ratio (2.94) x 262 and divide by the tire diameter in inches (33). 262x2.94/33=23 teeth, which sounds about right with that tall a tire and those gears. You'll really want some 4.10-4.56 gears for it with that tire. The equation is very precise and you can find your exact diameter by measuring the circumference and dividing by 3.1416 (aka: pi) to make it even more accurate.