Well, you've gotta realize that they don't plan on knocking off horsepower just for the hell of it. They try to change the power delivery of the engine. Take the Honda 919 (Hornet). They didn't want an engine that's really peaky on horsepower way up in the rpm band. For a mostly "street" bike, they wanted more power and torque down low. Who wants to zing it up every time in commuter traffic?

I think you already know this though. Mainly it's from problems that arise from moving the power lower in the rpm band. Different cams, different intake, different exhaust, different carbs or injection map, etc....

I find it funny that manufacturers and magazines keep referring to parts used from other bikes as "derived". E.g., "R1 derived engine, brakes, forks, etc... However they changed the bore, stroke, pistons, cams, carbs, injection, fork spring and valving, travel length, brake rotor diameter...." Huh? In other words, they have NOTHING in common except maybe an engine casting or overall look or fork tube or something. They're basically completely different components.

Don't think it of as "detuned". Thinkof it more like a completely new design "Based" on something else.

Emrah

 

Plus, manufacturers don't want one of their models completely making another of their models obsolete. Take the R1 and FZ1 as an example. Why would Yamaha make a bike (FZ1) that performs just as well as a more expensive (though not my much) supersport (R1) but is more comfortable and and practical for everyday usability.

Emrah