Harley-Davidson's Knucklehead engine released back in 1936, and despite its age, models with the engine can sell for over $200,000 even today.

If classic motorcycles had a royal family, the Knucklehead would be one of those grand uncles everyone points at and says, “There! That’s the reason motorcycling looks the way it does!” It is bulbous, ...

Harley-Davidson is famous among motorcycle brands for more than a few things: its muscular chopper motorcycles, long-standing history of innovation, and in-your-face road warrior attitude, to name a ...