Well check this:
You've got the 2002 FZ1 which uses a motor based on the engine from the R1
Quoted from Yamaha's Page:
"The FZ1 is fitted with an engine based on the R1. With redesigned cylinder head, the compact 998cc liquid-cooled beast is fed by four side-draft 37mm carbs. The crankshaft, 10% heavier than the R1, increases inertial mass, which improves the around-town ridability. "
Then you've got your R6 which is based on the engine from the R1.
Everybody say hmmmm.
Plus Richard hit the nail on the head. The R6 is the number 1 selling street bike ever made.