Hitman shimano gear shifter 7*3=21speed Bicycle Brake Disk

A bicycle brake is a device that slows or stops a bicycle when it is moving. There are three types of brakes, namely cycle rim brakes, cycle disc brakes, and drum brakes. Most bicycles are equipped with either rim or disc brakes. Other than appearances, the important difference between traditional rim and disc brakes is where the force is applied. With a rim brake, callipers apply braking power to the rim's outside edge. The braking surface of disc brakes, on the other hand, is transferred from the rim to the rotor. Bicycle brakes operate by pushing a resistive brake pad onto the braking surface of the rotating wheel. The friction force increases when the brake lever pressure is raised. The bicycle slows down as a result of this, as well as the tyre's grip. Disc brakes produce a tremendous amount of force, frequently considerably more than is required to stop a road bicycle safely. The resultant braking power is significantly more constant when you pull on a disc brake-equipped lever.