As one of the university which applies Green Campus in Indonesia, Sebelas Maret University Surakarta keeps on developing the management of an eco friendly campus. In a bid to decrease the impact of environment polution, UNS is planning to add free bike as transportation for their students and academic staffs in campus. This research is aimed to find the probability of user demand of free bike. The data was collected by interviews with the variables are waiting time, travel time, and the bike comfortness. It is found that the best scenario for choosing bike as a media transportation (90,37%) is when waiting time of bus campus is long (more than 22 minutes), bus travel time is normal and cycling comfort is good. Waiting time, travel time, and cycling comfort condition are variables that have a big influence on probability of potential demand.