If you don't want to guess about the actual reach of the stem, use this cool online stem calculator. http://www.brightspoke.com/t/bike-stem-calculator.html

The angle of the stem in relation to your head tube angle will determine how much reach a stem really is.

Looks like it is made for threadless stems though, not sure if that will help you out.

You should find out the exact reach of your handlebar too.