The UTB-0 is one of the most unnecessary but also most important utensils for living in cities. The UTB-0 is a primitive bicycle that strips away all the functions and equipment that have been developed until now, to just the wheels and the frame. What is important to us today, as we enjoy more than adequate conveniences, is not convenience or a wealth of equipment. Rather, what we need is to return to the physical sensations that have worn out and become dulled as we have ceaselessly pursued convenience. Also, we need to return to the sense of time that has been lost through a focus on efficiency. The UTB-0, which has purely expanded physical functions through focusing on riding, should enable riders to enjoy the time they spend in transit, which has been disregarded in the name of efficiency.