When I first came to Shenzhen, bikes were so common it took me a while to notice them. However, by the time I did notice them, they (the bikes) were actually being pushed off the streets in favor of cars and the emergent commuter economy, which did not yet have a metro and so relied on cars. In turn, the number of motorized and electric bikes became prevalent, with motorbike taxis a common form of transport in parts of the city with inconvenient or no public transportation.
In November, the city (or at least the inner districts) went full on bike and now these rentals can be found throughout the city. Rental bikes are provided by at least four different private companies and for 1 rmb per half hour, one can pedal from subway station to home, or take a leisurely ride. These new bikes have disrupted two businesses that were once controlled by private entrepreneurs: site-seeing bikes in Mangrove Park and motorbike taxis. The most recent massive removal of motorbike taxies from the urban environment that took place in April of this year. Nevertheless, banning motorbikes and electric bikes has actually been an ongoing, decade-long project. See reports here (2003), here (2007), here (2009), and here (2011).