History of Winter Tires in Japan

Abstract
The history of winter tire development in Japan is described. Studless tires (tires without stud pins) have been developed to replace studded tires whose use has been prohibited due to the dust problem caused by stud pins scraping the road surface. With the spread of studless tires, the icy road surface was polished by the tires and changed to a very slippery and smooth icy road surface. Therefore, the history of development of studless tires is the history of improvement of performance on ice. In order to improve the frictional force of the tire on the icy road surface, it is necessary for the rubber to adhere to the icy surface. For that purpose, adhesive friction, edge effect, and water film removal effect are important as friction mechanisms.