Disk drive biasing timing recovery measurements for spiral tracks based on radial location of head

In an embodiment of the present invention, a disk drive comprises a head actuated over a disk including a plurality of spiral tracks, wherein each spiral track comprises a high frequency signal interrupted at a predetermined interval by a sync mark. The read signal from the head is processed to detect a plurality of the sync marks in spiral track crossings. A plurality of timing recovery measurements are generated corresponding to the detected sync marks, and the timing recovery measurements are biased based on a radial location of the head. A servo write clock is generated in response to the biased timing recovery measurements, and the servo write clock is used to write product servo sectors to the disk.