When you use a gear with a small diameter to drive a gear with a large diameter what is increased speed or torque?

User Avatar
Wiki User
December 15, 2008 9:07PM

Torque is increased on the larger, driven gear. The increase can be calculated as the ratio of the radii of the two gears. For example, if the small gear has a radius of 2 cm and the larger gear has a radius of 10 cm, the torque ratio is 10/2 (ten to two), or 5/1 (five to one). So the driven gear is producing 5 times the torque of the driving gear. The speed ratio is the reverse; the driven gear is rotating at 1/5 the speed of the driving gear.