A plastic or fibreglass shell, known as a "fairing", is placed over the frame on some models to shield the rider from the wind, aid in aerodynamics and protect engine components in an accident. Drag is the major factor that limits motorcycle speed, as it increases at the square of the velocity, with the resultant required power increasing with the cube of velocity. As evident in the streamlined appearance of new performance motorcycles, there is much aerodynamic technology included in the design. Since the 1958 FIM ban on motorcycle designs that cover the wheels or the rider, e.g., "dustbin" fairings, no major manufacturer has provided fairing to overcome the effect of the turbulence caused by the spinning front wheel, which prevents the motorcycle from cutting a clean path through the air. "Dustbin" fairing can improve aerodynamic performance without substantially compromising the rider's ability to control the machine, if the fairing is designed and tested for the effects of side winds.

Screens, also called windshields or windscreens, can be built into a fairing or be attached to an otherwise unfaired bike. They are usually made from transparent high-impact acrylic plastic. They may be shaped specifically to direct air flow over or around the head of the rider even if they are much shorter than the seated rider.

An example of a fairing on a Honda CBR1000F

In the absence of a fairing or screen, a phenomenon known as the windsock effect occurs at speeds above 100 km/h (62 mph), where the rider becomes a major source of drag and is pushed back from the handlebars, tiring the rider.[citation needed] However, these motorcycles still effectively push their way through the atmosphere with brute force. A cabin cycle, which has a hull that wraps around the basic cycle frame, solved the problem of aerodynamics by isolating driver from outside air.

Modern fairings on touring and sport-touring motorcycles dramatically improve a rider's comfort and attention on long rides by reducing the effect of the wind and rain on the body. They also help keep a rider warm in cold weather or high wind chill conditions, reducing hypothermia. Heated hand grips, and even heated seats, also improve rider comfort in cold weather. Motorcycles from a number of manufacturers now have electric screens, introduced on the 1986 BMW K100LT, which raise and lower the screen with the push of a button to the optimum height for conditions.

Craven's Golden Arrow panniers

Saddlebags or panniers

Saddlebags or panniers mount on either side of the rear wheel behind the saddle to carry parts, tools, and/or travel gear. They can be made of fiberglass, ABS, leather, Cordura, or other appropriate sturdy material. They are normally standard items on touring motorcycles, but are usually optional on other types of motorcycles. They can be model-specific and available from a motorcycle's manufacturer, or after-market and designed to fit on numerous models.

Heated handgrips on a BMW

Heated hand grips/seats

As motorcycles lack climate control or proper protection from the wind, some manufacturers offer heated seats or hand grips to relieve the discomfort of low temperatures experienced during night riding or the colder months. They can also be added on as after-market accessories and are powered by the bike's electrical system.

Luggage rack

A common addition to many bikes is an attachment onto which bags or other luggage can be fastened. This removes the need for rider backpacks and is generally a more secure and safe way to add carrying capacity to a motorcycle.

Sidecar