The Difference Between Low Gear Ratio & High Gear Ratioby Sam Grover
Gears are used in a number of different machines, from cars to factory equipment to pedal-powered pushbikes. They all follow the same principles, though, using one toothed wheel to move another toothed wheel.
The main function of gears is to provide torque. Torque is a turning motion; when you open a doorknob, you are applying torque to it. Gears use torque by transferring a larger gear's speed into a smaller gear's torque or vice versa.
Low ratio gears are gears where the pinion gear (attached to the motor) has fewer teeth than the ring gear (the gear it turns). So if the pinion gear has 10 teeth and the ring gear has 30 teeth, the ratio is 1:3. The pinion gear has to spin three times to make the ring gear spin once. This is good for torque but not speed.
High ratio gears are the opposite; the pinion has more teeth than the ring gear. So if the ring gear has five teeth while the pinion has 10, the ratio is now 2:1. For every one time the pinion spins, the ring gear spins twice to keep up, which is good for speed but not power.