An assisting apparatus for using power from a moving member to assist the operation of a bicycle transmission comprises a power transfer mechanism, a drive coupling mechanism, and a position maintaining mechanism. The power transfer mechanism moves in one of a first direction and a second direction to upshift the bicycle transmission, and the power transfer mechanism moves in the other one of the first direction and the second direction to downshift the bicycle transmission. The drive coupling mechanism couples the power transfer mechanism to the moving member to move the power transfer mechanism in one of the first direction and the second direction, and the position maintaining mechanism prevents the power transfer mechanism from moving in the other one of the first direction and the second direction.