[JesseK]

Thanks for the data Richard!

4"x1:1 versus 3"x1:2

(4"x1:1 is a 4" wheel with a 1:1 ratio, direct driven; 3"x1:2 is a 3" wheel with a 80T gear on the motor and a 40T gear on the wheel)

Since mass will affect every race, is the added mass to get a 1:2 gearing on a 3" wheel worth the complexity versus a direct drive 4" wheel? I don't think so. My charts show that a 3"x1:2 is only 0.1 seconds faster than a 4"x1:1 since adding gears adds weight (gear mounting, extra axle primarily). I'd suggest trying it with both and seeing what you gain from the flexibility in the design from 4"x1:1.

Edit -- Whoops -- the calculator didn't factor in another efficiency drop due to the extra gears -- so now 3"x2:1 is just on par with 4"x1:1.