What is sprocket on a bicycle?

A sprocket, also known as a cog, is a component of the bicycle drivetrain that is responsible for transmitting power from the pedals to the rear wheel. It is typically made of metal and is attached to the rear wheel hub or cassette.

The number and size of the sprockets on a bicycle's rear wheel determine the range of gears available to the rider. A larger sprocket will result in a higher gear ratio, which is more difficult to pedal but allows for greater speed, while a smaller sprocket will result in a lower gear ratio, which is easier to pedal but slower.

Modern bicycles typically have anywhere from 7 to 12 sprockets on the rear wheel, with the ability to shift between them using a derailleur or internally geared hub. The front chainring(s) also contain(s) sprockets, which can similarly affect the gear ratio and overall performance of the bike.

Maintenance of the sprockets is critical to ensuring a smooth and efficient ride. Over time, the teeth of the sprockets can become worn or damaged, which can affect the bike's shifting and overall performance. It is important to regularly clean and lubricate the drivetrain, and replace any worn or damaged sprockets or chainrings as necessary.