A crank assembly comprises a crank arm, a front sprocket unit, and a plurality of chain-drop control protrusions. The plurality of chain-drop control protrusions is configured to inhibit a drive chain from getting into a space provided radially inwardly from the plurality of chain-drop control protrusions and between the crank arm and the front sprocket unit in an axial direction. The plurality of chain-drop control protrusions is configured to be provided to at least one of an axially inwardly facing crank-surface of the crank arm and an axially outwardly facing sprocket-surface of the front sprocket unit. The plurality of chain-drop control protrusions is spaced apart from each other in a circumferential direction with respect to the rotational center axis.