1) Certain exerciser 2) Certain gang member 3) Chopper rider 4) Cycle enthusiast 5) Cyclist 6) Fonda was this in Easy Rider 7) Gang member 8) Harley owner 9) Harley rider 10) Harley-Davidson rider 11) He only has two wheels 12) Hog enthusiast 13) Hog lover 14) Hog owner 15) Hog rider 16) Just one of the gang Found on https://www.crosswordclues.com/clue/biker
a person who rides a bicycle, motorcycle, or motorbike, esp. in competition or as a hobby. · a member of a motorcycle gang. Found on https://www.infoplease.com/dictionary/biker