So many terms...
Biker to me says harley dude.
Squid...dumb kid who cant ride the over powered bike he has chosen and does so without gear."Wife Beater"... mandatory.
Motorcyclist...those weird BMW guys.
Crotch rocket guys...all those guys on Gixxer's and Ninja's who seem more concerned with appearances than riding abilty.
1% er's...those guys that just refuse to grow up.Serious hard-core killers,drug dealers and extortionists.(most have jobs now and answer to the man like the rest of us).

very few TRUE 1% er's left.
Newbie...self explanantory.
RUB... rich urban biker.

See also: Poser.
Iron Butt...guys who put down some serious miliage. I think its a genetic thing. No nerve endings or pain receptors present in gluteus maximus.
Clubber...more interest in looking good/getting drunk/gettin' laid....not bad work if you can get it.
Poser...sweet azz ride...no real riding skills...uses sand paper to remove chicken strips and to scuff up knee pucks.
Bambi or Mid-Life'r...never rode before.Gets sudden urge at age 45. Drops bike first day.Posts for sale ad the following day.
Organ donors...see "Squid".
And what every motorcycle guy wants:
A Pillion,a Seat-Warmer,a Back-Warmer,a Seat Cover,etc....some hot chick in LuLu lemons,flips flops,white tube top with her pink thong poking out.
Tons more...yer Belly Shovers,Gearheads,Geritol boys.
I call myself a rider.Used to be a biker.
RSD.