A gear changer of a power transmitting device includes an input shaft to which a rotational force is inputted from an engine, an output shaft for outputting the rotational force to a rear wheel, and a plurality of speed change gear pairs for transmitting the rotational force from the input shaft to the output shaft. A slider member for selecting one of the speed change gear pairs to transmit the rotational force from the input shaft to the output shaft is supported by the output shaft. Selection of one of the speed change gear pairs is accomplished by moving the slider member in an axial direction by means of a shifter mechanism. A pump rotary shaft, to which the rotation is transmitted from the input shaft, is disposed at a location between the input shaft and the shifter mechanism in a circumferential direction of the output shaft.