Shimano Iron Works was established in 1921 by Shozaburo Shimano in Sakae, near Osaka. In 1951 the company changed its name to Shimano Industrial Co.

Shozaburo Shimano’s first product was the ‘3.3.3.’ single freewheel. In 1956 Shimano produced its first derailleur, also called the ‘3.3.3.’. It was a pull-chain model loosely based on a Cyclo design, with one sprung pivot and one unsprung pivot. However, Shimano’s real interest at this time lay in hub gears. It ceased production of derailleurs in 1958, when it launched its three speed hub gear (inevitably called the ‘3.3.3.’), which was immensely successful. The 3.3.3. hub gear was significant because it established Shimano as more than a freewheel and derailleur company. Shimano has always been more ambitious than its competitors in terms of the scope of its product range.

Shimano re-entered the world of derailleurs in 1965 with its first parallelogram derailleur (called the Shimano 3.3.3.!) and gradually came to dominate the market in following decades.