A bike or motorcycle is a motor vehicle with a strong frame and two wheels. Various types of bikes are available, such as sport bikes, cruisers, motorcycles, scooters, touring motorcycles, dirt bikes, and mopeds. Dirt bikes are also known as off-road bikes. These motorcycles are designed for use in mud and rough terrain such as dirt roads. Small and light, trial bikes are special dirt bikes used for motorcycle trials. Some people ride off-road bikes simply for pleasure.

Dirt bikes can be identified from their basic features, such as huge wheels with tires that knobble, no street equipment, and an engine which is small and light. The construction is simple but rugged. These bikes have little body work although they feature long suspension travel. Off-road motorbikes have two-stroke or four-stroke engines which could be either air-cooled or water-cooled. Young riders generally purchase dirt bikes with engine sizes from 50 cc to 150 cc, whereas older ones tend to purchase 250 cc, 450 cc and 650 cc bikes.

Most of the 125cc dirt bikes which are sold have a four-stroke, air-cooled engine with a single cylinder. These really powerful bikes are definitely meant for younger riders. In fact, the 125cc four-stroke engine is known as a racing motor since dirt bikes possessing this engine are common in the lineup for motorcycle races. They are very good on rough and difficult tracks due to their body framework and control. Dirt bikes with 125cc engines are much in demand.