The 1900-1920s Harley-Davidson Motorcycles Channel features some of the earliest models around. Check out vintage Harleys at HowStuffWorks.
1915 Harley-Davidson 11F
The 1915 Harley-Davidson 11F motorcycle had an advanced-for-its day 11-horse F-head V-twin engine. A proper three-speed transmission was offered along with a magneto and electric lighting system incorporating a taillight. Read about this historic Harley.