It's a fair compromise. The 449-cc Unicam single uses a heavier crankshaft (relative to the 450 in the motocross bikes) to make it more tractable, and a wide-ratio six-speed includes a tall top ...

I was trying to ride a dirt bike. And my role model that day was not ... engineers you’ll get a sort-of consensus that the 450 puts out 45 hp. You can’t get a torque figure.