Shamelessly stolen from GarryH's Kiwibiker thread...
Accident waiting to happen - Getting wiped out while sitting stationary.
Adventure Tourist - One who leaves the road and ends up deep in the bush.
Agricultural incident - When a Harley is involved.
Arsewipe - The guy that falls off in jeans or other inapproriate clothes and looses large amounts of skin off his arse.
Crotch Sniffer- Biker who follows too closely then finally runs into the back of someone.
Double Act - Rider and Pillion crashing.
Kamakazi - Bike tries to take a car out.
Out for a Duck- Crash on first ride on a new bike.
Sliced Cheese - (enough said)
Taking a U-Turn - (enough said)
Smashing Pumpkin - Not be wearing a helmet.
Tree-hugger - wrapped around a tree