How does a chain and sprocket work?

Answer 1

To see how a chain in sprocket works in action, you can turn a bicycle upside down and turn the pedals.

But here are the particulars:

A sprocket is a type of gear, or "Cog-Wheel". Its teeth slot into the gaps in a chain, hence gripping it. The chain then essentially becomes an extension of the circumference of the sprocket. This circumference can be made to form irregular shapes such as an oval. It can even be serpentine if redirected by additional sprockets or guides (maybe shaped like the letter S for example). The chain on your bicycle is actuated (moved) by the forward Sprocket, which is known as a Pinion. Your legs power the pedals, which turn the pinion. The teeth on the Pinion grip the chain and the chain rotates about it, transferring the movement energy of the pinion to that of the Sprocket (the gear/s on the back wheel). If the Pinion is small in comparison to the sprocket you will have to pedal faster and you will travel slower. The effort to move the pedals, however, is reduced. If the Pinion is comparitively large to the Sprocket then you will pedal slower and travel faster. Additionally the effort required to move the pedals will increase. The size ratio of Pinion to sprocket is altered by a system of gears. On a bicycle this is usually some kind of derailer, which displaces the chain from one sprocket, forcing it to catch on another. On bicycles with more than 7 gears there is normally a similar derailer to move the chain at the Pinion end. Both a chain and its driving gears are prone to wear over time. This is due to the frictional forces acting between the two. Such a systems' life span can be extended by regular lubrication. The correct chain tension is also important to minimise wear. Sometimes it is sufficient to simply remove a Sprocket and turn it round, as the teeth tend to wear more on the "pulling" side than on the "pushing" side. It should be noted, however that eventually both components will require replacement.