[SpudRider]

You might now ask, what makes the shift drum move when I tap the shift lever with my foot? Inside the orange oval of the photograph below, you can see how the gears, shift forks, and shift drum are installed in the crankcase.



The top of the shift drum extends into the right crankcase cover, where it is capped with the shift star. When your foot taps the shift lever, it actuates the shift pawl. The shift pawl engages, and rotates the shift star, which actuates the shift drum. The shift pawl and shift star are located inside the red oval in the photograph below.