Bikes are categorized depending on function, number of riders, construction, gearing or by propulsion. The most common bikes known are utility bikes, mountain bikes, hybrid bikes, racing bikes, cruiser bikes and BMX bike parts. Bikes move by being steered by the rider. They can also be classified as men's bikes, women's bikes and kids' bikes to fit the different needs. Women's bikes usually have a lower standover height. This design is called a step-though frame which allows women to mount and dismount even when wearing a skirt or dress. Other types of bicycles called recumbent bikes are more aerodynamic and allow the rider to lean forward onto a support while operating pedals.

Mountain bikes

Mountain bikes are created for off-road cycling. They are created to traverse rocks, washouts, steep declines, dirt trails, logging roads and other environments that are not paved. Mountain bikes are designed to withstand stresses of rough terrain, which has obstacles like logs and rocks. These types of bikes have wheels that have rims 559mm or 26 inches. They have wide wheels and knobby tires to help in traction on uneven roads and absorb shock. On the handlers, Mountain bikes can also be fitted with bar ends to help in giving extra leverage when climbing hills. Because of their strength, mountain bikes can be used in all day endurance, cross-country biking, free-ride biking down the hills and other competitions. Mountain bikes can come in different designs such as fully rigid, hardtail, soft tail, and dual or full suspension. Modern designs have been incorporated into mountain bikes and they are also available in tandem configuration.

Road bikes

Road bikes are designed to be used on pavements, for racing, recreation or for both. These are the bikes that are used in racing, sporting, triathlons, cyclocross, touring, fitness or tracking. They are also known as racing bicycles. Therefore, road bicycles usually have more gear combinations and less hi-tech features. Road bikes are different to other cycles in that they have narrow tires, a high pressure and the rolling resistance is smooth to decrease. Their gears are usually multiple derailleur or with single-speed and fixed gear also in existence. Road bikes are lightweight in construction. Variations of road bikes include touring bicycles, hybrids, vintage road bicycles, utility and recumbent bicycles. Fitness road bikes are made to be comfortable, versatile and with speed.

Kids' bikes

Kids' bikes are designed to be used by kids as from the ages of as early as 2 years. Kids' bikes vary in sizes. These sizes are determined by the wheel diameter. In adults the sizes are determined by the seat height and frame. These bikes have coater brakes which tend to be easier to young kids to use. With hundreds of kids bikes in the market, when picking them the first thing to consider is size so that the bike fits the intended child. Sizes are 12", 16", 20" and 24". Design is another factor to consider. Dangerous designs should be avoided. Price is also considered, with the heavy bikes being cheaper than the lighter ones.