City 2 Rochdale 0
Michael Boulding opened his account for the Bantams as City made it three wins out of three.
The new signing from Mansfield got in front of his marker to head home a superb cross from Peter Thorne after 20 minutes.
City's leading scorer put the hosts further in front on 36 minutes when he found himself unmarked in the six-yard box and he nodded home his fifth goal of the season from a Paul McLaren free-kick.
The 2-0 lead perhaps flattered the Bantams against an impressive Rochdale side who had more of the ball but lacked City's cutting edge.
Adam Le Fondre hit the cross bar in the second half and Paul Arnison had to clear off the line as the Bantams defended well.
At the other end, Boulding almost got his second when he hit the inside of the post and the ball rolled across the line before being cleared.
Victory puts Stuart McCall's men in second place on goal difference behind Shrewsbury.