The Harley Davidson logo is one of the most well known logo’s around the world both within the biking community and without. Being that the Harley Davidson company itself predates the use of computers for design work, as does it’s well known logo. Though hand designed originally, several fonts that resemble the font in the logo are available.
Users in the MyFonts.com community have identified Compacta as closely resembling the Harley Davidson logo font.
If you would like some background about the Harley Davidson company and the history of it’s logo, you can check out this article.