An image forming apparatus including a housing, a sheet cassette, a second roller, a gear train, a pendulum gear, and a stop member. The gear train includes a gear rotatable together with the second roller. The pendulum gear is movable between a meshing position where the pendulum gear is in meshing engagement with the gear train and a separated position where the pendulum gear is separated away from the gear train. The stop member allows the pendulum gear to move from the separated position to the meshing position. In the state where the sheet cassette is at an internal position and the stop member is at the second position, the stop member is out of contact with a part of the sheet cassette in a first direction but contacts the part of the sheet cassette in a second direction.