The single speed Allen Urban model incorporates a 6061 aluminum frame, high performance 451 MM wheels, a patented folding stem and delivers a smooth, responsive ride. As a single speed model, the Urban is best suited for flat terrain or small hills. The key benefit of this model is that the 451 MM wheels deliver an exceptionally comfortable ride. With the exception of our Downtown model, all Allen folding bicycles use 451 MM wheels, which are slightly larger than standard 20″ wheels and deliver an exceptionally comfortable ride. The Urban uses a patented press-linkage folding design on the frame and headset which makes folding and storing this bicycle quick and easy. A patented rear wheel lock system allow the bicycle to be rolled like a cart when in a folded position for easy transport. Rider size range: 4’8″ to 6’5″/Max rider weight: 230 LB. Bike ships 100% assembled – unfold and go.