I did the first (miserable) year on 42x15 which was higher than my commute gear and it sucked balls.
Lowering the gear to something closer to my commute gear (more like 42x16) and probably the dry weather made for a much nicer ride. Spin to win. It might be flat but it's still a long way and you'll appreciate the easier gearing, especially if there's a wind, or some rain, etc.
I did the first (miserable) year on 42x15 which was higher than my commute gear and it sucked balls.
Lowering the gear to something closer to my commute gear (more like 42x16) and probably the dry weather made for a much nicer ride. Spin to win. It might be flat but it's still a long way and you'll appreciate the easier gearing, especially if there's a wind, or some rain, etc.