A folding bicycle is a bicycle that can be broken down into a more compact size. These bicycles are convenient for traveling or commuting on public transportation. They consist of different pieces and hinges that can be easily removed or shaped to collapse the bicycle into a smaller size.
The folding bicycle is popular in cities where cars are impractical, expensive, or where traffic is too busy to permit them, such as New York City, Beijing, Tokyo, or other major urban metropolises. They can be used to dock on a bus, subway car or airplane while traveling longer distances. Many bus lines now carry racks for the bicycle or the folding bicycle.
The folding bicycle can also simply be for the family with too much junk and not enough garage space. It is commonly used on vacations when space again does not allow the bulk of a full-sized bicycle with luggage carriers or in a hotel room.
The different types of the folding bicycle have many different kinds of hinges and joints at which they fold. Different joints result in different sizes and different shapes, as well as varying difficulties in folding and unfolding. The steering column on the folding bicycle is often shortened with a hinge at the bottom and folded inward toward the body of the bike. The rear and front wheels can be moved in toward the body, and the seat is pushed lower into the frame on many varieties.
Some types of bikes allow for the middle frame to be removed, collapsing the folding bicycle from the ends, leaving the wheels and steering and seating columns as they are. Another popular method allows all of the tubes and gears of the bike essential to control, steering, and pedaling to remain intact, conserving the balance and structural integrity of the bike.
The folding bicycle, as an athletic bike, is not as effective as a regular bicycle. With the folding frames, they are geared toward comfort and convenience over the strength, stability, and speed of a regular bicycle, although there are expensive folding bicycles made for speed. A fold in the middle of the frame of many of these bikes absorbs energy and result in a slower ride. These, along with smaller wheels, translate into a rougher ride. Add more pieces, with more opportunities to break or fail, and the folding bicycle presents some challenges and discomforts over the normal bicycle.