Yang Daming, an engineer of a bicycle factory, and his wife Liu Yun, a textile factory worker, both find themselves laid off. Daming hides his situation from his family and secretly starts wiping bicycles in the street. As Yun decides to stay at home to take care of her family, their two children, Xiaohong and Xiaogang discover their father's secret and share their parents' sorrow in different ways. While cleaning bicycles, Daming observes and studies the various bicycles and he starts working on a new bicycle derailleur.