Finally Beijing is stocking up with a system of bike rentals. The bikes come in 3 colors: Blue, red and yellow. They have advertisements in the wheels so that you easily recognize them. There are various bicycle rental stands all across the city and you can rent them per hour or per day or even for weeks. Most of the rental stations are conveniently located near subway stations or major bus stations or where many people are. It is a great idea, not only for visitors.
Also just to let you know: You can get a bicycle repaired in almost any place in the city. There are bike repair guys at many street corners. Well… not in the newly constructed fancy areas like Central Business District (CBD) or Financial Street (Jinrong Jie) but everywhere else.