How does bar position affect handling?

The fore and aft movement of the bar is essentially just for rider preference and comfort in ergonomics. It essentially allows you to increase or decrease the size of the "riding compartment" . Some riders feel too cramped with the bars in the rear position and others feel to spread out in the forward position, basically it is what feels best for you. The handlebar position should not affect the handling of the bike as long as it is in a comfortable position for you. If you change the height of the fork tubes in the clamps this will affect the handling but the handlebar position wont unless it affects your ability to turn because you are uncomfortable with its location.

Moving the bars forward or back will also change YOUR centre of gravity on the bike so it will affect handling in some situations. Just imagine more weight onthe forks (with bars forward) coming into a corner and you 'll get a steeper head angle, and quicker turn in, but it will aslo mean the forks will be working harder and will partially unweight the rear end, making it ride (slightly) higher.... opposite if the bars are to far back. Some bikes are sensitive to this, others aren't... one of the magazines did a piece on it.... sorry can;t remember which one!!!!! duh...

If the bar is higher it will make you want to stand more if it is lower it will make you want to sit down so you might want somewhere in the middle. But it also decides on how tall you are the taller you are you might want it higher. The reverse for if you are short