HOW the Spur Gear and the Bell Gear work
You divide the spur gear, into the bell gear like this, 52 Divide by 13 = 4 turns for the Bell gear and 1 for the Spur
52/13= 4 Low End Power / Hill Climbing
52/15= 3.46
52/18= 2.88
49/13= 3.76
49/15= 3.26
49/18= 2.72
47/13= 3.61
47/15= 3.13
47/18= 2.61 Top End Power / SPEED
Robinson racing Comb 48/16 = 3