According to Cycle World, the R6 has a top speed of 164. I had it up to 169 today, and i think it still had a little more in her, though not much. I was tucked as far as humanly possible under that screen, helmet resting on the tank. Whats the fastest you've ever gone? Next time I have the opportunity, I'm gonna try folding the rear view mirrors back for less wind resistance. If the Cycle World test is accurate, I'm guessing the mud flap causes a lot of wind resistance in back. My bike is stock aside from the fender eliminator.