donorcycle
n. A motorcycle, particularly one that is extremely powerful and fast.
Also Seen As
donor-cycledonor cycle
Other Forms
donorcyclist n.
Etymology
organ donor + motorcycle
Examples
2003
I'm told that ER doctors refer to powerful, zippy motorbikes as "donorcycles," as in organ donations from brain-dead riders after accidents.
—Carlos Alcala, “Tough riders have to prove they can take mountain terrain,” Sacramento Bee (California), July 20, 2003
2003
Of course, the risk is not equally divided. Inexperienced riders, especially those who have not taken training courses, are more likely to die. Sport bikes, which emergency-room doctors call "donorcycles," as in organ donation, are more dangerous than their less powerful counterparts.
—Alex Berenson, “Born to Be Wild, but at a Cost,” The New York Times, July 06, 2003
1987 (earliest)
Organ donors are not just people who die. They are young, healthy people who die unexpectedly — usually from a violent accident, suicide or crime, such as a motorcycle crash or a gunshot wound to the head. Transplant surgeons sometimes refer to motorcycles as "donorcycles."
—Don Colburn, “Transplants: Who Lives? Who Decides?,” The Washington Post, January 20, 1987
Notes
As the first example citation says, this bit of medical slang is based on the grisly fact that a disproportionate number of fatal traffic accidents happen to those who ride "sport bikes," those sleek and colorful machines that are really not much more than an absurdly powerful engine bolted to a couple of wheels. (The high accident rate of these bikes has spawned another name for them: suicycles.) Most of those who ride such bikes are young and healthy, which, if their time comes, makes them ideal organ donor candidates.

A reader named "ZenMan" passed along the following tidbit:
With Donorcycles (the movement), bikers have organ donor cards that say their organs can only be donated to states without helmet laws.
Posted: July 08, 2003