In the early 1970s, demand created by the bike boom in the United States exceeded the capacity of European manufacturers. SunTour and Shimano filled the vacuum. SunTour focused on refining existing systems and designs for mid-level and high-end products. Like Shimano, SunTour initially did not sell complete group-sets, so it teamed with other parts makers, such as Sugino for cranksets and Dia-Compe for brakes, so it could sell a complete line of SunTour branded components. Under these types of production agreements, companies did not have design control; if a cooperating component manufacturer decided not to upgrade or redesign its products, SunTour could do little about it. Shimano decided to greatly expand its research and development staff to 200 employees, enabling the company to end its component marketing agreements in order to produce hubs, pedals, brakes, and other components on its own in competition with its former partners. In comparison, SunTour chose to continue with its existing research and development staff of some 20 persons, and remained primarily a bicycle gear and shifter manufacturer.