See
Figure 1. Some motorcycles have a heel-toe shifter lever. With this shift lever, upshifts can be made with the heel of the left foot. Downshifts can be made with the toe.
Pushing heel-toe foot shift lever all the way down (full stroke) shifts the transmission to the next lower gear.
Lifting the foot shift lever all the way up (full stroke) shifts the transmission into the next higher gear.
Release the foot shift lever after each gear change. This allows the lever to return to its central position before another gear change can be made.
Figure 1. Heel-Toe Foot Shift Lever