Just in case any info that develops here is helpful to others, I've had a consistant issue with fore to aft balance. Jay stayed with me Sun night and rode to the airport with me so we had a lot of time to discuss this. At that time I decided since I had a witness, I'd rank my skis subjectively to Jay as to which were more or less comfortable for me in terms of fore/aft balance as I have felt big differences between the worse and best. Then when I got home, see if that ranking correlated to my ski's ramp angles. (some of this is repetitive as I started to hijack another thread. My apologies.)
Ends up they correlated perfectly.
I marked a spot on both ends of the boot then measured from the bottom of the boots to the bottom of the skis. All 3 pairs of skis have a positive delta angle (ramp is the forward tipping built into the base of the boot, while delta angle is the total forward tipping built into the ski/binding - not sure if there is a name for the total combined forward tilt).
Head I75m's - - 3mm
Head 1100 xrc's sw - - 5mm
6 Stars - - 6mm
(this is not in degrees, just height differences from the mark on the front toe piece compared to the mark on the tail piece.)
This is also the ranking of worse to better for me in terms of fore/aft balance management. The 6 stars are much easier for me to stay out of the back seat than the I75m's.
So, for me, my body seems to like ramp. Yet, this is all different for different people. Jay noticed that my hip to knee length is quite long while my knee to ankle is short. This ratio is probably but one of many components that go into what if any ramp angle helps a particullar person balance fore/aft. Some people need to remove ramp angle to get comfortable.
Paul (instructor at the camp from vail) and I were talking about this and he has a discontinued Dalbello boot that has the allen wrench ramp angle adjustment. He told me how even a quarter turn either direction made very noticible differences in his skiing. He also told me that the first time he got himself dialed in perfectly it was just shocking how his fore/aft balance problems went away. (anyone know how Paul is doing- he got injured the last day of the camp?)
Witherall in his book believes most of the population benefits from greater ramp angle. Yet, there are also people, a smaller percentage, that are the oppisite in that ramp angles need to be less for them to manage fore/aft balance. Bottom line seems to be that individual skeletal angles and lengths determine this and are very different from person to person. Witherall has a process to zero in on cant amounts and then to on-slope adjustment. HH as an even more detailed process (just look at the forms and measurements both parties use - HH's is much more complete).
Yet, witherall and HH both do not seem to have a systematic initial measurement system for an initial ramp/delta angle for a particullar individual. It's all trial and error. SI came up with a dual scale setup to see how much weight was on the front vs back of the boots. He tried this with 4 individuals. 2 guys and 2 females. He measured all four then increased the ramp the same for all four and re-measured. In 2 of the 4 cases this improved the balance and in 2 of the 4 cases the balance became worse. This shows two things.
1. what helps one person may make another person worse
2. SI may be onto a process that could add objectivity into initial ramp angle assessment.
Interestingly, and maybe someone can help me with this, at the whole camp everyone told me to hold my hands out in front of me, and not let them drop. But, moving my hands in front of me and holding them, for balance to be maintained, causes my body to shift more to my heels. I can feel this just standing and raising my arms forward. On the other hand, putting something to raise my heels makes it all work playing around on the wobble board. My normal weight just standing around is on my heels and it's quickly worse as any flexion is done. (probably due to my long upper leg relative to my lower leg)
Anyone have any leg ratio data - ankle to knee / knee to hip vs ramp angle? The literature seems barren other than trial and error. Perhaps SI's little test could be expanded with a set of test students and developed into a real process. I can't wait to get down to the ramp angle I need and to ski again. The difference for me skiing the I75M's with its slight delta angle vs my 6 stars which have 2 times the delta angle of the I75m's is dramatic. Yet I believe in my case even more angle will help.