A transfer assembly, comprising: a counter member, disposed opposite an image carrying face of an image carrying member, the counter member having a contact face to contact to a recording medium; an engagement/disengagement unit to engage and disengage the image carrying face of the image carrying member and the contact face of the counter member, the engagement/disengagement unit including a cam and a cam driver to drive and rotate the cam; a pressure device to apply a force to a transfer nip defined between the image carrying face of the image carrying member and the contact face of the counter member in a state in which the image carrying face of the image carrying member engages the contact face of the counter member; a recording medium feed device to feed the recording medium to the transfer nip; and a transfer device to transfer an image from the image carrying member to the recording medium sandwiched at the transfer nip, wherein the cam has an outer face having a given shape so that when the cam is at a first rotation position, the image carrying face of the image carrying member and the contact face of the counter member are separated, and when the cam is at a second rotation position, the image carrying face of the image carrying member and the contact face of the counter member contact each other, characterized in that before the recording medium, fed from the recording medium feed device, enters the transfer nip, the cam is started to rotate from the first rotation position toward the second rotation position at a given speed while increasing a rotation speed of the cam, wherein at a timing after the recording medium reaches the transfer nip and at which the cam is at the second rotation position to press the image carrying face of the image carrying member with the contact face of the counter member, the force of the pressure device applied to the recording medium at the transfer nip is increased to a level of a transfer performance. a counter member, disposed opposite an image carrying face of an image carrying member, the counter member having a contact face to contact to a recording medium; an engagement/disengagement unit to engage and disengage the image carrying face of the image carrying member and the contact face of the counter member, the engagement/disengagement unit including a cam and a cam driver to drive and rotate the cam; a pressure device to apply a force to a transfer nip defined between the image carrying face of the image carrying member and the contact face of the counter member in a state in which the image carrying face of the image carrying member engages the contact face of the counter member; a recording medium feed device to feed the recording medium to the transfer nip; and a transfer device to transfer an image from the image carrying member to the recording medium sandwiched at the transfer nip, wherein the cam has an outer face having a given shape so that when the cam is at a first rotation position, the image carrying face of the image carrying member and the contact face of the counter member are separated, and when the cam is at a second rotation position, the image carrying face of the image carrying member and the contact face of the counter member contact each other, characterized in that before the recording medium, fed from the recording medium feed device, enters the transfer nip, the cam is started to rotate from the first rotation position toward the second rotation position at a given speed while increasing a rotation speed of the cam, wherein at a timing after the recording medium reaches the transfer nip and at which the cam is at the second rotation position to press the image carrying face of the image carrying member with the contact face of the counter member, the force of the pressure device applied to the recording medium at the transfer nip is increased to a level of a transfer performance.