Hobieboy, this is a great question because balance is such an important skill in skiing. Without an awareness of how we are balanced as we ski, and an ability to manage our state of balance as we choose, we are destined to mediocre skiing at best.
Our skis will perform differently, depending on how we pressure them along their fore/aft plane. To be able to exploit the full range of their performance capabilities we need to learn how to move to different states of fore/aft balance at will, and perform with competence when we get there.
Bob is so correct when he says that the mantra that says a skier should always be forward is on the surface a bit misguided. As I said above, a skier should learn to perform in all fore/aft states. That said, there's a reason that "get and stay forward" advice is so often used by ski instructors. Being aft balanced is a nemesis problem for a large percentage of recreational skiers. It's an innate human reaction to move and stay aft when the skis start to accelerate down the falline, and/or a bit of terrain intimidation sets in. Of course, it's the exact wrong thing to do, but it's a survival instinct we skiers are saddled with, and it takes some training to overcome. Often, telling them to "get and stay forward" can work to take them out of the back seat and least back to fore/aft centered.
Ok, so back to you, hobieboy. That you recognize when you are aft balanced, and then act to correct it, is an indication you have already started to develop your fore/aft awareness and your balance skill base. Terrific! Could your boot set up have something to do with being aft when you don't want to be there? You bet! Both cuff and ramp angle can have a major affect on your ability to get to the front of your foot in a strong and comfortable stance. I would suggest getting to a "GOOD" boot fitter and have him take a look.
Beyond boot setup, get a handle on what Pierre was saying about how joint articulations affect fore/aft balance. Ankles flexed forward move your weight fore, and when extended back move your entire body and your balance point aft.
Knees extended move your hips up and forward, and your balance point fore. This is why instructors will often tell their students to "stand up" when they're trying to get them out of the back seat. When knees are flexed, the hips drop and move behind the feet, and the balance point moves aft.
And finally, flexing forward at the waist moves balance fore, and straightening up at the waist move balance aft. It's the combination of what's happening at those 3 joints that determines our fore/aft state of balance.
Now,,,, how do you know if what you're doing is working? Direct you're attention to what you're feeling on the base of your foot, and in your shin and your calf. Where do you feel pressure on the base of your foot? Is it concentrated on your heels? On the balls of your feet? How about your boot cuff? Do you feel your shin mashing into the front of your boot, or your calf laying into the back of your boot? The combination of what your feel will tell you how you're balanced,,, and your knowledge of how joint articulations affect fore/aft balance will tell you what you need to do if you want to adjust it.
Here are some general landmark guides:
- If you feel only light pressure on your shin, and pressure concentrated on the balls of your feet, you're fore balanced.
- If you feel heavy pressure on your shin, and pressure concentrated on the balls of your feet, you're strongly fore balanced.
- If you feel heavy pressure on your shin, and also on the heels of your feet, you may be bending the front of the boot, but you may not be fore balanced, and may not be directing much pressure to the front of your ski. Fools gold.
- If you feel pressure concentrated on your heels, and light pressure on your calf, you are aft balanced.
- If you feel the back of your boot strongly indenting itself into your calf, regardless where you feel pressure along the base of your foot,,, YOU ARE OFFICIALLY IN THE BACK SEAT.
- If you feel pressure equally distributed across heel and ball, and only light contact of shin or calf to boot cuff, you are center balanced.
So why ski in what state of balance? Fore balanced directs more pressure to the front of the ski, and helps to initiate a fast and powerful direction change at the start of a turn. In the body of the turn, fore pressure can keep those tips digging and turning, and if done strongly enough, can even allow the tails to drift a tad to help tighten the turn even more.
Aft releases the tips from cranking a turn and holding you back, and allows the skis to squirt forward. It works well at the end of a turn, to release the skis and allow them to flow uninhibited out of the prior turn, and into the next.
Center balanced is probably the most relaxing, energy efficient fore/aft balance state to ski in. The foot is loaded across it's entire base, and can operate to it's max capacity as the magnificent balancing instrument it is. The muscles of body can relax and allow a strong and structurally aligned body to assume the responsibility of bearing the forces of a turn. Modern skis (how many more years will we be saying this) allow beautiful arc to arc skiing to happen while in this efficient state of balance. Center balancing loads them equally from tip to tail, which allows them to engage the snow consistently along the length of their edges, and flow smoothly and cleanly through a turn.