On Harley-Davidson motorcycles, "FL" is an abbreviation used to denote a specific series or model of motorcycles. It stands for "F" meaning "Big Twin engine" and "L" indicating a "Wide Glide front end." The FL series is known for its larger engine displacement and classic touring design.
Harley-Davidson has used various FL models over the years, such as the FLSTF Fat Boy, FLHR Road King, and FLHT Electra Glide. These motorcycles typically have a heavier and more substantial frame, larger engines, and a distinct front end design with a wider front fork and larger headlight. FL models are often associated with long-distance cruising and touring, offering a comfortable riding experience for extended journeys.