Binding mounting position question

[Stephen*]

Is there any consensus on binding mounting position?
I’m guessing it’s one of those “it depends” sort of questions.
specifics in this case are:
Voile Hyper V6 BC 183
Meidjo 3
TX Pro, MP 30
6’ 3” / 190 all up weight
All around skiing, no target or main application, any conditions. Average ability.
I’m hearing some like 1 - 2cm back from recommended on this ski.
I have no opinion, or experience to draw on.
would love to hear any thoughts / theories / beliefs / preferences and rational for.
thanks

[TomH]

I just go boot center on mid-sole line, and have never had an issue. I think with NTN gear, starting at mid-sole is the way to go.

[Stephen*]

So, for example, Voile has directions for finding boot center, and measurements for all their skis in relation to mounting bindings, such that boot center is located per their recommended location.
And this is what you do, TomH ?

I’m still interested to know if others have different ideas on this, and what the thinking is on that.

Voile chart found here: https://www.voile.com/Voile_Ski_Boot_Center_Chart.pdf
Voile_Ski_Boot_Center_Chart.pdf

[TomH]

Pretty much. I'm surprised Voile doesn't just have the topsheets marked for boot center (maybe they do). Boot center on NTN boots is generally marked, but is actual middle of the boot sole (toe to heel), as opposed to 75 mm boots, where you'd measure from heel to pin-line and split the difference.

The rationale for 2-cm back or so, is that when you're in a tele turn, the pressure is driving down closer to the toe for the rear foot, so by moving the mount point back, you're theoretically applying pressure closer to the boot center point for an alpine mount. This was more common in 75mm than it is with NTN boots.

[jtb]

I also do boot center on the line on the ski. From memory, Voile's graphics put the "Made in Utah" shield at boot center, but they make you measure from the tip to find the exact point. I wonder if there's some variability in where the graphics land, so measuring from the tip is more precise?

[Pherick]

Most skis do great at manufacturer's BC.

I think it's worth being familiar with the concept of CBF-CRS (Center Ball of Foot Center Running Surface) for edge cases like older skis or modern nonstandard skis.

The goal of the method is to place your uphill/rear foot's pressure at a position on the ski where the opposing forces from the snow are balanced. Boot too far forward/backward and the back/front of the ski "wins" and you're fighting the ski with poor control. In this method your heels-down performance is considered secondary as it's so much easier to control..

For example I have a pair of fully symmetrical, fully rockered skis. Boot center is the exact middle of the ski. Dry-fitting everything it seemed like there was going to be a lot of ski behind my foot with a dropped knee and I wouldn't be near enough to the center of the sidecut to carve my turns well with my uphill ski. I used CBF-CRS to guide moving the binding backward. I didn't go all the way to CBF-CRS, but in this and a few other cases CBF/CRS and manufacturer BC lay out good max forward/backward boundaries within which I make a compromise that seems right for the ski given my experience on others.

Maybe another way to think about it is BC is heel-down ideal and CBF-CRS is heel-up ideal. Since you're doing both at the same time there's a trade off, as well as a magic foot size for some skis that hits both marks at the same time.

BUT- all of this is nerdery and a remnant from pre-computerized ski designs where it seems there was a little more alchemy involved in finding where to put the boot.

The bottom line is that you can't go horribly wrong following the manufacturer's recommendation.

I have found Voile's mount points to be great on the hypercharger and objective BC, fwiw, with a 291mm TXComp/Pro.

[dschane]

I don't think there's consensus. IMO, for Voile skis, their recommendations for boot center are perfect. There are other brands where I move my mount back 2 cm because their recommendation consistently feels more forward than I prefer. But, I will always start with the suggested mount point and go from there. AT/tele makes no difference to me.

My recollection for Voile is that, with new skis, there's a sticker for the mount location. I could be wrong. Regardless, I would always double check their spec. sheet.

[Stephen*]

Thanks for all the input. Pretty much lines up with my interpretation of all I have heard / read regarding the subject.
Makes sense, from a liability perspective, for Voile to not mark the ski and make the installer responsible for measuring to Voile’s specified location.
I received a set of Objectives direct from Voile that used damaged top sheet paper material as packing for the skis.
Made me realize how the top sheet is applied (and now, that there could easily be small variability in placement of the top sheet on the ski during manufacture).
Talked to a very knowledgeable shop manager today who said, in his experience, all the skiers he knows who mounted back were of a generation, and also aggressive skiers. Kind of ties into what Pherick said about skis of the past.
I sometimes (I’m being generous) overthink things — this is probably one of those times…
I’m fine with recommended binding location.
If anything, with a size 30 boot on a 183 ski, I may end up slightly behind designed anyway?

[bobbytooslow]

I think it's worth being familiar with the concept of CBF-CRS (Center Ball of Foot Center Running Surface) for edge cases like older skis or modern nonstandard skis.

The goal of the method is to place your uphill/rear foot's pressure at a position on the ski where the opposing forces from the snow are balanced. Boot too far forward/backward and the back/front of the ski "wins" and you're fighting the ski with poor control. In this method your heels-down performance is considered secondary as it's so much easier to control..

For example I have a pair of fully symmetrical, fully rockered skis. Boot center is the exact middle of the ski. Dry-fitting everything it seemed like there was going to be a lot of ski behind my foot with a dropped knee and I wouldn't be near enough to the center of the sidecut to carve my turns well with my uphill ski. I used CBF-CRS to guide moving the binding backward. I didn't go all the way to CBF-CRS, but in this and a few other cases CBF/CRS and manufacturer BC lay out good max forward/backward boundaries within which I make a compromise that seems right for the ski given my experience on others.

This is great. I love the logic that for tele skiing, the priority should be optimal control of the rear ski with the ball of the foot (and that the heel-down front ski is easy enough to control no matter what). Mount enough tele skis, and you get a sense of where a binding should be relative to the ski's shape just by looking at it. This is a much more clinical description of how to get there.

[Stephen*]

Thanks a lot bobbytooslow!
Now I’m questioning my earlier resolve to go with recommended …
🤔 🙂

[dschane]

Now I’m questioning my earlier resolve to go with recommended

Knock that thought right out of your head.

[Stephen*]

Talked about this with a very knowledgeable ski tech today who said, among other things, that when he was doing ski testing for Karhu, back in the day, it took a 4cm move for him to really feel a difference in the ski. He knew just one tester who could tell a 2cm move. That person wasn’t me, so I’m gonna just let it go and move on… 👉
Now, maybe he was just tying to calm me down, but makes a good story.

[Paul Lutes]

Always start with the manufacturer's recommendation, but never accept it as gospel. There are few joys greater than moving bindings off the recommended mount point and having the skis suddenly come alive.

[mo pow]

I monted Lynx on Voile V8 at recommended position and was a little disappointed in how they skied in powder. They were capable but not as fun as I hoped. Last season I moved them back one hole set (3.8cm) and love them now.

[jasonq]

i think everything said above is right. it depends, and i think the answer is usually 0-2.5cm behind the AT/Alpine boot center mark.

I think the reason for that is four-fold.

1) as mentioned above, the rear ski the center of pressure is more forward due to raising the heel, dropping the knee, however you think of it. the vertical component of force is at the toe (exactly at the pins for TTN or TTS).

2) And you can't just look at the vertical component of force. there is also a moment applied (exactly around the pins for TTN or TTS) by the binding's activity. This moment will weight the tip more and tail less than it would be by just the vertical component. Said another way, the more active the binding the more the tip is weighted by the rear ski.

3) even the front ski can have the weight more forward than a typical AT/Alpine turn. this is style dependent. But going back to the roots of the tele turn, the boots had zero forward or rearward stability. The tele turn was the solution to having forward and rearward stability in the turn without the equipment providing it. to have an adaptable dynamically stabile position, both the front and rear foot have the weight on the ball, or at least towards the ball. That allow fluid weight adjustment forward and backwards, especially in the case of slowing down. stand in your favored tele stance and weight you balls on both feet and shift weight as far forward and backward as you can. Now do the same but with the weight on the heel of your front foot. extreme, and unrealistic, but demonstrates the original intent. As equipment has improved, this has become less important, which is why it is now style dependent. But in general, the front foot weight is more towards the front than center of the arch, especially finishing the turn vs AT/alpine.

4) the intangibles, what you just happen to like. unfortunately, this might be the largest factor.

for me, my style, and likes, it all adds up to -2cm.