A bicycle component position correcting device comprising: a first sensor (64; 74) configured and arranged to detect a current absolute value of a positioning angle of a movable part (16d; 18d) of a bicycle derailleur a second sensor (66; 76) configured and arranged to detect both a movement direction of the movable part (16d; 18d) and an amount of movement of the movable part (16d; 18d); a comparison unit configured and arranged to compare the current absolute value of the positioning angle of the movable part (16d; 18d) to a prestored reference value of the positioning angle of the movable part (16d; 18d) in response to a component operation command; and a position adjuster configured and arranged to selectively output an adjustment command to the movable part (16d; 18d) that adjusts the absolute value of the positioning angle of the movable part (16d; 18d) in accordance with both detected results of the first and second sensors (64, 74; 66; 76), characterized in that the component operation command is a gear shift command, and in response to each gear shift command, the position adjuster is configured and arranged to selectively operate the movable part (16d; 18d) to adjust the current absolute value of the positioning angle of the movable part (16d; 18d) before shifting to the prestored reference value of the selected gear position before shifting based on a detected result of the first sensor (64, 74) upon determining that the current absolute value of the positioning angle of the movable part (16d; 18d) before shifting does not match the prestored reference value of the selected gear position before shifting; and the position adjuster is further configured and arranged after adjustment of the absolute value of the positioning angle of the movable part (16d; 18d) before shifting to operate the movable part (16d; 18d) to perform the shifting operation, and to position the movable part (16d; 18d) based on the detected results of the second sensor (66; 76) in response to the gear shift command; and the position adjuster is configured and arranged to selectively operate the movable part (16d; 18d) to adjust the absolute value of the positioning angle of the movable part (16d; 18d) after shifting to the prestored reference value of the targeted gear position from the gear shift command based on a detected result of the first sensor (64, 74) upon determining that the absolute value of the positioning angle of the movable part (16d; 18d) after shifting does not match the prestored reference value of the targeted gear position from the gear shift command. a first sensor (64; 74) configured and arranged to detect a current absolute value of a positioning angle of a movable part (16d; 18d) of a bicycle derailleur a second sensor (66; 76) configured and arranged to detect both a movement direction of the movable part (16d; 18d) and an amount of movement of the movable part (16d; 18d); a comparison unit configured and arranged to compare the current absolute value of the positioning angle of the movable part (16d; 18d) to a prestored reference value of the positioning angle of the movable part (16d; 18d) in response to a component operation command; and a position adjuster configured and arranged to selectively output an adjustment command to the movable part (16d; 18d) that adjusts the absolute value of the positioning angle of the movable part (16d; 18d) in accordance with both detected results of the first and second sensors (64, 74; 66; 76), characterized in that the component operation command is a gear shift command, and in response to each gear shift command, the position adjuster is configured and arranged to selectively operate the movable part (16d; 18d) to adjust the current absolute value of the positioning angle of the movable part (16d; 18d) before shifting to the prestored reference value of the selected gear position before shifting based on a detected result of the first sensor (64, 74) upon determining that the current absolute value of the positioning angle of the movable part (16d; 18d) before shifting does not match the prestored reference value of the selected gear position before shifting; and the position adjuster is further configured and arranged after adjustment of the absolute value of the positioning angle of the movable part (16d; 18d) before shifting to operate the movable part (16d; 18d) to perform the shifting operation, and to position the movable part (16d; 18d) based on the detected results of the second sensor (66; 76) in response to the gear shift command; and the position adjuster is configured and arranged to selectively operate the movable part (16d; 18d) to adjust the absolute value of the positioning angle of the movable part (16d; 18d) after shifting to the prestored reference value of the targeted gear position from the gear shift command based on a detected result of the first sensor (64, 74) upon determining that the absolute value of the positioning angle of the movable part (16d; 18d) after shifting does not match the prestored reference value of the targeted gear position from the gear shift command.