Bicycle design involves creating a two-wheeled vehicle that is efficient, comfortable, and safe for riders. Key components include the frame, wheels, handlebars, and seat. The frame can be made from materials like aluminum, carbon fiber, or steel, each offering different benefits in terms of weight and durability. Aerodynamics and ergonomics are crucial in bicycle design to enhance performance and rider comfort. Features such as gear systems, brakes, and suspension systems are also considered to improve functionality. Designers often focus on specific types of bicycles, such as mountain bikes, road bikes, or hybrid bikes, to meet various riding needs.