The single-speed Allen Sports Urban model contains a 6061 aluminum frame, superior rolling 451 mm wheels, a patented folding stem and delivers a smooth, responsive ride. As a single-speed model, the Urban is most suitable for flat terrain or small hills. 451 millimeter Wheels deliver improved performance and handling over the usual 20 or 16 inches found on so much folding bicycles. The Urban uses a patented press-linkage folding design at the frame and headset, which makes folding and storing this bicycle fast and simple. A patented rear wheel lock system allow the bicycle to be rolled like a cart when in a folded position for simple transport.