Rinker and Spittle each shot 5-under-par 67 and joined Calcavecchia, who had a 3-under 69, at 7-under 137.
Mike Harwood and Mark McNulty, who were tied with Calcavecchia after Thursday's play, both were over par Friday. Harwood fell into a tie for 10th after a 2-over 74 left him 2-under for the tournament. McNulty was 6-over in his last six holes and sagged to a 4-over 76 to fall into a tie for 32nd, seven strokes off the lead.
Calcavecchia, who won the British Open in 1989, opened the second round with back-to-back birdies and closed with another while mixing three birdies, three pars and nine pars in between.
Rinker's opening round was marred by two double bogeys and a bogey but he was bogey-free Friday.
Spittle made his move with six birdies in a nine-hole span over Nos. 9-17.