A method of writing product servo sectors to a disk of a disk drive is disclosed. The disk comprises a plurality of spiral tracks, wherein each spiral track comprises a high frequency signal interrupted by a sync mark at a sync mark interval. The sync marks in the spiral tracks are detected to synchronize a servo write clock used to open a demodulation window during which the high frequency signal in the spiral tracks is demodulated to generate a position error signal for maintaining the head along a first servo track while writing product servo sectors along the first servo track. The demodulation window is then shifted by an integer number of sync mark intervals to initiate a seek to a second servo track. The head is then used to write product servo sectors along the second servo track.