The History Of Harley-Davidson's V-Twin (And All The Nicknames, Too) - Jalopnik

Harley-Davidson’s V-twin is at the center of the brand’s motorcycle identity, shaping the characteristic sound and engineering direction since the company’s first V-twin in 1909. The article traces how the 1909 atmospheric-valve Model 5-D set the pattern for later refinements, even as the company faced wars, financial crises, and changing rider preferences. Over time, Harley engines picked up widely used nicknames tied to visible design traits, including the Knucklehead, Panhead, and Shovelhead. It also describes how both fans and engineers drove iteration, correcting flaws from one model generation to the next. Despite setbacks, including tensions during the Great Depression and the AMF era of the 1970s and 1980s, the V-twin story is framed as repeated resilience.