Motorcycles are powered by internal combustion engines that use pistons to convert gas into rotary motion. This rotary motion powers the back wheel, which in turn drives the rider forward. Motorcycles can be used for sport, utility, or passenger transport. They can have a variety of suspension types, engine sizes, and gearing ratios. Almost all motorcycles have headlights, taillights, and turn signals. Most have a speedometer, odometer, and tachometer. Some have a reserve tank feature that uses the petcock to switch from the regular fuel supply to a shorter pipe in the case of an emergency.

In the United States, the most popular motorcycle brands include Honda, Harley-Davidson, Yamaha, Kawasaki, Suzuki, and Polaris. When shopping for a motorcycle it is important to try out several different models to find the right fit. A test ride will let the rider experience the feel of the bike in a controlled environment. After the test ride the rider should be comfortable operating the motorcycle in traffic and under varying conditions.

Riders should avoid alcohol and drugs before riding a motorcycle. These substances impair judgment, balance, and throttle control. They also reduce the rider’s reaction time. In addition, high speeds cause a rider to become a significant source of drag, tiring the rider and increasing wind resistance.

Compared to cars, motorcycles have a much higher rate of crippling and fatal accidents per unit of distance traveled. This is primarily due to the lack of protection and the rider’s exposed body. To minimize this risk, all motorcyclists should wear helmets and protective clothing.