The primary distinctions between dual sport and supermoto are as follows: A dual-sport has a front tire that is 21 inches in diameter and a rear tire that is 19 inches in diameter, whereas a supermoto has a front and rear tire that is 17 inches in diameter. A dual-purpose bike has somewhat more ground clearance, but a supermoto has a few inches less. The mass of a dual-sport is about 50 percent more than that of a supermoto. All-terrain vehicles (ATVs) are large, four-wheeled vehicles with high centers and large tires designed for on-road and off-road use. They are built for a variety of tasks including utility work, travel over rugged terrain, and recreation. Some models can be converted to multiuse machines by removing one or more of their seats. Dirt bikes are small, two-wheel motorcycles used for riding around dirt tracks or trails. They are not meant for road use and cannot be ridden on paved roads. Dirt bikes are easy to ride and fun for all ages; however, like any other motorcycle activity, they can be dangerous if done improperly. Mopeds are small, two-wheel motorized vehicles designed for easy transportation around town. They are not meant for long trips or difficult terrain and only come in one size - 16 inches wide. Mopeds are popular among young people because of their lightweight design and ease of driving. However, many states have laws restricting their use because of their low speed limits.