Sway/set back seatpost - newbie question??

[seadragon]

I have a bike but the fit is a bit tight. I need to need to move my bum so it is less over my feet if you know what I mean, would a set back seatpost do this?

I cant find a clear explanation of what a sway-back setback seatpost is in clear and plain english, any assistance would be greatly appreciated :-) .

I also need a longer stem to increase my reach slightly, but I can resolve that myself

thanks in advance

[aspender]

Yes, a set-back seatpost is going to put your bum further back. This will also increase the reach to the bars so make one change at a time.