Fairing makes motorcycles more aerodynamic. Fairing components swoop backward from the front of the motorcycle and direct air in a streamlined manner off the top and bottom, rather than allowing air to hit the front, which will cause the motorcycle to act like a parachute and slow down in the face of wind resistance. Fairing comes in full, half and quarter varieties. These designations describe how much aerodynamic advantage they add.
Quarter fairing allows motorcycles to go faster. By deflecting the air off the front of the bike, they reduce resistance, which in turn allows the bike to move forward at a quicker rate. To imagine how it accomplishes this task, try putting your hand out a car window while driving on the highway. When you hold your palm parallel to the ground, it moves through the air easily; when you hold it perpendicular to the ground, you feel a lot of resistance. The size of your hand hasn’t changed, but its arrangement in relation to the oncoming wind has.
Quarter fairing also increases fuel efficiency. By decreasing wind resistance, the engine does not have to work as hard to go a particular speed. Since it doesn’t have to work as hard, it doesn’t burn as much fuel, which means you don’t have to fill it up as often.
Quarter fairing provides a cheaper option than full fairing or even half fairing but, for the casual motorcycle rider, has essentially the same effect. Full and half fairing are designed for high speeds, such as racing motorcycles and police motorcycles; cruisers on which riders usually use quarter fairing, do not require this kind of speed. Rather, they just need to reach a standard highway speed while conserving fuel. Quarter fairing provides an acceptable degree of aerodynamics without the fuss and hassle of a bulky, more expensive fairing.