A motorcycle in which a shaft is used to transfer the power to the back wheel (as opposed to chain or belt).

The main benefit of shaft drive is low maintenance and high durability; it is thus used on many touring motorcycles. The disadvantages of shaft drive are extra weight, extra complexity, and inability to change final drive gear ratios. Thus, most sports/racing motorcycles use chain drive.

A swimmer

A shaftie is a motorcycle that is so incredibly rubbish it is physically incapable of wheeling. Weighing more than Russel Grant on his way home from doing a big shop in an armoured car, riding a bike without a chain is like anal sex without lube. Unnecessary and quite unpleasant.