We get asked a lot about why you would move the binding on a skate ski, when it comes to classic it is easy to understand that moving it would affect the amount of kick/glide performance that you get out of a ski. Since you are not compressing a skate ski completely underfoot, adjusting your binding has a greater impact on the gliding performance and feel of the ski.
When looking at a ski from the side you can see that the ski tapers towards the tips and tails, as you move the bindings backward you are moving your weight back on the bridge of the ski and lowering your heel in comparison to your toes. With your heel being lower this gives the skis the feeling as if they are going to squirt out from underneath your feet.
The other piece of this is taking weight out of the tip which allows the skis to float more when conditions get soft and chewed up. Less weight up front means the skis aren't going to plow into the soft snow as much which helps keep acceleration when the skating deck starts to fall apart.
By moving your bindings forward you are moving your weight over the center of the camber and putting more pressure into the front of the ski which is where the steering and handling of the skis come from. This can be helpful when conditions are very firm packed or even icy and allows the ski to have a little more contact patch with the ground. If you can hold your speed better in those conditions, a lot of the time your skis are going to be fast no matter where you put your bindings.
In general we keep the movement of skate bindings minor and float in-between positions of -2 and +1, large adjustments forward often have negative effects on the skis climbing performance and general feel of acceleration. Some brands and some lengths cater to a certain binding position over others. For example: Rossignol and Fischer skis in 186/188 and 191/193cm lengths almost always ski better in a -1 (sometimes -2) position due to the way the camber distributes load.
We can test your skis to see where they will ski best on paper but a lot of the setting comes down to feel underfoot. If you are more comfortable and feel as though your skis are faster it is likely you are going to have a better time and ski faster because of it.
