A Bikie is somebody who rides a Harley Davidson or a Cruiser style Bike. Bikies are Generally members of a Bikie Gang.
A Bikie is different from a Biker who is someone who rides any kind of bike. Also termed as a motorcyclist but such a name is generally thought of as uncool.
Hey Jane did you know that John is a bikie.
"really I would have never known, I have never seen him riding a Harley"