A crown portion for bicycles includes a first tube through which the steerer tube of a front fork extends, and two arms which are connected to the first tube and two second tubes are respectively connected to two distal ends of the two arms so that two leg portions of the front fork extend through the second tubes. Two passages are defined through each of the two arms and a separation ridge is located between the two passages to maintain the structural strength of the arms. The two passages communicate with the first tube so as to define two openings in an inner periphery of the first tube, and communicating with the second tubes so as to define two openings in an inner periphery of the second tubes at the conjunction of the second tubes and the arms.