my new attempt

[suicideneil]

Not exactly. Basically, if you just have a spur & pinion, the smaller the pinion/bigger the spur, the more torque but less speed is generated. With a bigger pinion/smaller spur, more speed & less torque is generated. The torque of the motor remains the same either way, but altering the gear ratios can generate more torque or speed, depending on the application. Few motors have enough torque to directly drive the diffs and wheels of a vehicle, except for some outrunners (see Sike's projects for that stuff). The reason why some motors dont like being over geared, such as the Hvmaxx motors, is because they are to weedy, so more torque is required to turn the wheels = large gear reduction of about 25:1 or more. Some powerful motors like neus are so strong they like to be over geared abit, or at least run a smaller reduction ratio, since if they are 'under worked', they tend to over rev and heat up. Its all good fun it is...