ZipZap® Gear Ratios

Introduction

Radio Shack makes available several different gear sets for the ZipZaps and ZipZap Monster Trucks.  Various combinations permit tuning the vehicle for speed, torque, or a combination of both.  Listed below are those gears and the computations for the resulting gear ratios.

ZipZap and ZipZap SE car and truck gears        ZipZap Monster Truck gears

Computations

ZipZaps and ZipZap SE Gears

gear set color     transfer gear     axle gear   blue 18 / 6 teeth 24 teeth green 18 / 7 teeth 23 teeth red 18 / 8 teeth 22 teeth

color set     pinion gear     first gear set     ratio     second gear set     ratio     total gear train ratio   blue 6-tooth 18 / 6 = 3.00 24 / 6 = 4.00 3.00 x 4.00 = 12.00:1 green 6-tooth 18 / 6 = 3.00 23 / 7 = 3.28 3.00 x 3.28 = 9.86:1 red 6-tooth 18 / 6 = 3.00 22 / 8 = 2.75 3.00 x 2.75 = 8.25:1

ZipZap Monster Truck Gears

gear set color     transfer gear     axle gear   green 32 / 8 teeth 42 teeth red 32 / 9 teeth 41 teeth yellow 32 / 10 teeth 40 teeth orange 32 / 11 teeth 39 teeth

The motors for ZipZap Monster Trucks may be modified by replacing the 7-tooth pinion gear with the 6-tooth motor pinion gear from a ZipZap or ZipZap SE car or truck.  It is necessary to enlarge the hole in the 6-tooth gear--use a no. 62 (0.038-in dia) drill.  Then press-fit the gear onto the motor shaft.  Computations for both 6- and 7-tooth pinion gears are listed below.

color set     pinion gear     first gear set     ratio     second gear set     ratio     total gear train ratio   green 6-tooth 32 / 6 = 5.33 42 / 8 = 5.25 5.33 x 5.25 = 27.98:1 7-tooth 32 / 7 = 4.57 42 / 8 = 5.25 4.57 x 5.25 = 23.99:1 red 6-tooth 32 / 6 = 5.33 41 / 9 = 4.56 5.33 x 4.56 = 24.28:1 7-tooth 32 / 7 = 4.57 41 / 9 = 4.56 4.57 x 4.56 = 20.85:1 yellow 6-tooth 32 / 6 = 5.33 40 / 10 = 4.00 5.33 x 4.00 = 21.32:1 7-tooth 32 / 7 = 4.57 40 / 10 = 4.00 4.57 x 4.00 = 18.28:1 orange 6-tooth 32 / 6 = 5.33 39 / 11 = 3.55 5.33 x 3.55 = 18.92:1 7-tooth 32 / 7 = 4.57 39 / 11 = 3.55 4.57 x 3.55 = 16.22:1