In 1920, the production of fabric drive belts, typical for that time, was replaced with rubber belts at the Mitsuboshi Shokai factory, which had been established a year earlier. The rapidly growing company first expanded its product range to include transmission belts and then a wider array of automotive components, such as V-belts, multi-ribbed belts, and timing belt kits. Mitsuboshi also refined its rubber production technologies through experience gained in manufacturing bicycle tyres and inner tubes. Today, Mitsuboshi drive belts, perfected over decades, are highly regarded in the independent aftermarket for their superior quality and durability.