{"product_id":"harleydavidson-knucklehead-isbn-9780785837459","title":"Harley-Davidson Knucklehead","description":"\u003cb\u003eCelebrate the engine that changed the motorcycle world. \u003ci\u003eHarley-Davidson Knucklehead \u003c\/i\u003etells the entire Knucklehead story—accompanied by modern and period photography—from the very first overhead-valve V-twin Harley produced for the public through the post-war models, continuing right up until today, when aftermarket manufacturers reproduce complete Knucklehead crate engines because of its continuing popularity.\u003c\/b\u003e\u003cbr\u003e\u003cbr\u003e Motorcycle technology lagged far behind automotive technology since the earliest days of the internal-combustion engine. All that changed in 1936 when Harley-Davidson introduced the Model EL. For the first time ever, a company was manufacturing \u003cb\u003ea high-performance overhead-valve engine for the masses\u003c\/b\u003e.\u003cbr\u003e\u003cbr\u003e And what an engine it was—in addition to bringing \u003cb\u003estate-of-the-art technology\u003c\/b\u003e to the motorcycling world—\u003cb\u003ea work of art\u003c\/b\u003e. Because of the shape of its rocker covers, the engine was given a nickname to match its looks: the Knucklehead. The technology used in this engine was so advanced that it laid the foundation for every future Harley-Davidson motorcycle, including the current models built in the 21st century. To this day, every cruiser-style motorcycle adheres to the shape of that original Knucklehead.","brand":"Crestline Books","offers":[{"title":"Default Title","offer_id":44892748677349,"sku":"NP9780785837459","price":24.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1842\/7735\/files\/O_977b10db-4076-44fe-b393-dfe5b079caa4.jpg?v=1773102541","url":"https:\/\/k12savings.com\/es\/products\/harleydavidson-knucklehead-isbn-9780785837459","provider":"K12savings","version":"1.0","type":"link"}