The brakes are the most important cause of friction on a bike, especially to the rider. The sole purpose of the braking mechanism on a bike is to increase the overall frictional force acting on the wheel to such an extent that the bike is forced to slow or stop.

There are many different braking systems out on the market today that offer varying resistive abilities. The most preferred being disk brakes; these however are not the most common. The majority of bikes today are equipped with caliper brakes or V-brakes both of which are made up of two cable actuated brake arms that press a rubber brake pad against the side of the rim. This creates a frictional force between the two objects that opposes the direction of motion causing the bicycle to slow.