A sprocket[1] or sprocket-wheel[2] is a profiled wheel with teeth, or cogs,[3][4] that mesh with a chain, track or other perforated or indented material.[5][6] The name ‘sprocket’ applies generally to any wheel upon which radial projections engage a chain moving over it. It really is distinguished from a gear in that sprockets are never meshed together directly, and differs from a pulley for the reason that sprockets have tooth and pulleys are smooth.

Sprockets are used in bicycles, motorcycles, vehicles, tracked vehicles, and other machinery either to transmit rotary motion between two shafts where gears are unsuitable or even to impart linear motion to a track, tape etc. Probably the most typical form of sprocket could be found in the bicycle, where the pedal shaft bears a huge sprocket-wheel, which drives a chain, which, in turn, drives a little sprocket on the axle of the trunk wheel. Early automobiles had been also largely powered by sprocket and chain system, a practice generally copied from bicycles.

Sprockets are of various designs, no more than efficiency becoming claimed for each by its originator. Sprockets typically don’t have a flange. Some sprockets used with timing belts have flanges to keep carefully the timing belt centered. Sprockets and chains are also used for power transmission from one shaft to another where slippage is not admissible, sprocket chains getting used rather than belts or ropes and sprocket-wheels instead of pulleys. They could be operate at high speed plus some types of chain are so built concerning be noiseless also at high speed.