A disk drive has a spindle motor, a disk mounted for rotation on the spindle motor, and a head for reading from and writing to the disk. The disk includes a recording surface having a track that includes a first full servo wedge and a second full servo wedge, each of the first full and second full servo wedges defining a leading end and a trailing end and having, between leading and trailing ends, a preamble, a servo sync word, a track ID, and a plurality of servo positioning burst fields. The recording surface further includes user addressable data locations and a first partial servo wedge disposed between the trailing end of the first full servo wedge and the leading end of the second full servo wedge. The first partial servo wedge is devoid of preamble, track ID and wedge ID and includes a short servo sync mark that is different from the servo sync word. The servo sync mark defines a predetermined bit pattern that is immediately followed by a plurality of servo bursts.