After WWII, the company was facing stiff competition from European manufacturers. Motorcycles produced by Europeans were smaller, lighter, and very powerful. As they gained popularity, the company began to develop a new motorcycle in response. In 1952, Harley-Davidson introduced the K model. The K models were 750cc side-valve, V-twin driven motorcycles that retained plenty of power. They did well in competition and dominated with racers like Charles Carey. Harley-Davidson racers would go on to win several championships throughout the fifties, including seven straight victories at the Dakota 200. In 1957, the K model was replaced by the Sportster.