Budd–Michelin rubber-tired rail cars remained obscure in comparison with other competitors for the title, such as the "Pioneer Zephyr" and Union Pacific's M-10000. Rubber-tired rail cars achieved greater success in France, and similar rubber-tired subway cars have been adopted in Canada and Mexico as well as on numerous systems in Europe. During the 1920s, the American Budd Company, at the time a relatively obscure auto-frame supplier, developed an extensive working relationship with the French firm Michelin, which was best known for its tires. In 1929, Michelin built its first rail car, and by 1932 nine of its cars were in operating service, all of
Synthetic rubber Synthetic rubber A synthetic rubber is any artificial elastomer. These are mainly polymers synthesized from petroleum byproducts. About of rubbers are produced annually, and of that amount two thirds are synthetic. Global revenues generated with synthetic rubbers are likely to rise to approximately US$56 billion in 2020. Synthetic rubber, like natural rubber, has uses in the automotive industry for tires, door and window profiles, hoses, belts, matting, and flooring. The expanded use of bicycles, and particularly their pneumatic tires, starting in the 1890s, created increased demand for rubber. In 1909, a team headed by Fritz Hofmann, working at the Bayer