Seoul Public Bike is an unmanned rental system which can be used anywhere, anytime and by anyone, and which is run by the City of Seoul. In order to revitalise the public bike service and secure operational cost via sponsorship, a flexible brand identity was created. The logo with its two circles was applied to the bicycle design while the graphic elem-ents create a unified identity. The basic design elements are a combination of white and green, communicating a clean and eco-friendly image. The graphics on the bicycles can easily be changed to match sponsors’ advertising requirements.