Chris, I have had onside troubles for going on three years. I have started free skiing again some to try to figure it out. I seemingly can get around the offside no matter what. The free skiing helped isolate what I feel in the course. I do not feel where to turn onside. I do not have a sense of an apex. I feel as if I begin to parallel the boat but never feel when to turn. In the course, I am using the buoy to tell me when to turn. Because I just don't have an innate sense or feel through the ski when to turn, my reliance on the buoy to dictate the turn often results in being back and inside a bit. Like oh sh*t there goes the buoy got to go NOW. Offside, I feel where to turn. Some offside turns are up course some down course. I really don't care where the buoy is offside because I feel a distinct apex and I can feel the right place to turn.
The best onside I have had was when the water heated up from 50 to 87 and to correct the tail dragging I added 100/1000 tip, shallowed 20, and went back 30. The reason this seemed to help was that onside the ski would turn itself back toward the wakes before the boat picked me up. I am not sure about how lack of tip pressure factors in to the onside as it is most often discussed as an offside issue. My offside really does not like tip and I always seem to run less than most people do.
From the boat, observer said that I was trying to turn too early onside, before the apex, but when I try to wait on it, there I go down the lake paralleling the boat never feeling this mythical onside apex that the observer talks about.
Binding position: Most measurements are given with one boot or the other and assumes, apparently, everybody has the same spacing. Is one more critical than the other? Split the difference? For example, if the recommended is 29.25 and 17, would you expect 29 and 17.25 to be th right starting point?
I love this post because you have put some time into this one. First off, what bindings are you using? What is your spacing? How much pivot do you run in your boots? Also, what is your distance from tail of each of the heels of your boots? I measure both from my front heel and rear heel. In my case on a 66 MPD I run 28 5/8 & 16 5/8. For people who have small feet, I recommend having the rear heel measurement more accurate to start. If someone had size 8's and jumped on the 66 MPD, I would start them at 16 5/8, irregardless of where that put their front boot. That is just how I tend to do it and not everyone would agree with me on this topic. I just know that for me, if my rear heel is too far forward, no fin change can make the ski feel better. Post your ski, size, boots, location of each one, fin measurements, and wing angle and we can talk about what is going on. it sounds like to me that we have a boot issue, but I can't be sure without more info.
First, I have had enough different fin and binding settings over the three year onside slump that one would think that I would have hit upon something that worked merely by accident.
I skied well on the Monza. Still had onside issue but skied it to personal bests. On the MPD now 67, HO fin.
I use a FM front hardshell set dead center. I can rotate it any way you say. The rear is a wiley's tight at the forefoot and loose around the ankle such that I don't need soap to put it on. It is rotated toe out one hole which on the HO plate is quite a bit. Size 10 feet holding up a 6'0" 180 pound 55k skier.
I rode the MPD for a while with front boot at 28 5/8 rear 17 1/16. This was the spacing I had skied for 2.5 years. I can move the front FM in infinite increments. The rear in 3/8 bites. .725, 2.475, 6.795 tips
I then tried some numbers I saw posted by RINI. 29.25 17 1/16 2.485 .745 6.845 tips.
I am on your numbers now. 29.25 17 1/16 2.50 .770 6.845. Here, I do have to guard against tip rise toe side.
I can ski all of em. They merely feel different to me not better. They must all be in the ball park. I would, like to get my feet back closer together. In bad conditions, closer lets me rotate easier if I need to ...less of a long arc which for me is tougher to do in the rough stuff. I did like the fin forward setups better because the ski felt more free. Coming off a Monza, I am accustomed to feeling free before the buoy. MPD is running the show now before the buoy and when it works, the cross course tracking is amazing.
My best full pass is 35 which I have run with all the setups mentioned above. However, all I hope for out of my heel side is to be on my feet at the wakes. I do have some good heel side turns but my consistency over there is really raining on my confidence.
Maybe I need a shrink more than a ski coach. lol
Man this post is so long. I could go on and on. I really am trying to think my way out of this one. You are mighty gracious to help.