Road King's Timeline! Harley Davidson Road King is one of the iconic motorcycles in the world! Its story started from HD's FL series in 1941 with a 1210cc (74 cu in) Knucklehead engine! Harley Davidson factory has always loved these FL, EL, UL, ULH, FLT, FLH, FLHR, and so on for one reason or the other. I believe that the most hardcore Harley fans understand them but for most of us, they are just Klingon.
 However, before (FL) Road King was called Road King it was Hydra Glide from 1949 to 1958. From -58 to -65 it was Duo-Glide. From -65 to -79 a Tour Glide and then Electra Glide from 1979 to 1994 when it finally came Road King! Confused? Read from here more... HD FL in Wikipedia!