Binding Placement

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Cadman
Posts: 58
Joined: Tue Apr 06, 2010 9:50 am
Location: Crystal Mountain, Washington

Binding Placement

Post by Cadman » Sat Jan 13, 2018 11:56 am

I have been mounting all the skis that I have with demo bindings so I can move both heels and toes forward and aft. I am amazed at how much different the skis perform with just a few millimeters difference. I mounted a pair of 176 skis at the recommended mount point and I have an average foot size. (9.5US). They skied ok but after moving them 5mm forward, the ski became "alive". It tracked better and stayed right in the turn. I never use the mounting marks on the skis. I find what the suggested mounting point is and measure from the tail. I have found skis that the top sheet and side mounting lines to be inaccurate so I never rely on graphics.

I have been a proponent of moveable bindings for years. I have made a lot of believers out of the doubters by letting them ski my skis and adjust the position of the boot on the ski.
It is too bad that the binding manufacturers have not spent anytime educating people on how important binding placement is. I heard that Marker is discontinuing the Skizo binding that has infinite adjustment forwward and aft. They said that it did not sell. I believe that they just weren't very good at educating the public and marketing the binding correctly.

What are your thoughts on this?

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Akiwi
Posts: 370
Joined: Thu Jan 15, 2015 7:48 am
Location: Olching (Near Munich) Germany

Post by Akiwi » Mon Jan 22, 2018 8:37 am

I agree and disagree with you. I use the schizo bindings too, as I am never exactly sure what the ideal binding placement point on my home made skis is, so I like the flexibility of being able to adjust the bindings.

However I find it takes quite a large movement of a couple of CM or so before I realy notice the difference. Maybe I automatically adjust my weight distribution according to the binding position.

I am a little worried as I am building a pair of touring skis at the moment where I can't use the Schizo's.

How do you calculate the boot midpoint?
I am nobody. Nobody's perfect, so I must be perfect.

kit
Posts: 19
Joined: Fri Aug 07, 2015 3:37 am

Post by kit » Tue Jan 23, 2018 1:18 pm

FWIW, when I was getting started, I gleaned this from the site here that has served well:

"As a general rule of thumb, the ball of the foot goes at the mid running surface (MRS) and the center line of the boot goes to the waist, so for general design guidelines, the waist is usually back about 2.5-2.75 inches" since that is the distance from the ball of the foot to the center line on a size 27.5 size boot which is the average foot size."

I don't alter waist location in ski builds for different size skiers and boots within a model design, but do locate the "waist" or center of sidecut differently for different length skis on the assumption (so far reasonably accurate) that mostly shorter boots end up on shorter skis and vice versa. I do make slight changes to the setback to boot center from center of running surface for larger and smaller boots - that is, identifying boot center mark on the ski for binding mount. So I'll mount a boot with a 55 mm setback on a ski with a 50 mm setback without any noticeable effect. I'm religious about keeping the ball of the foot over the center of running surface (which I also unify in design with the maximum height of camber).

I have a pair of race stock Atomic GS skis that have slip and lock bindings adjustable fore and aft several centimeters on the slope - moving them off center doesn't seem to make much difference and for sure doesn't improve them as far as I can tell.

Cadman
Posts: 58
Joined: Tue Apr 06, 2010 9:50 am
Location: Crystal Mountain, Washington

Post by Cadman » Wed Jun 27, 2018 8:39 am

We have been testing skis all winter long on some all mountain skis and found the as little as 5mm change made a difference in the way the ski initiated. I even did some blind changes to the position without telling them what I did and let them ski a couple of runs on the same terrain.
If I made more than a couple runs, I noticed that I ended up adjusting my technique to compensate for the different position.
In my opinion, it makes the most difference on groomed runs.
As far as designing the ski, I measured feet with a Brannock devise like you find in a shoe store and found that between size 5 and size 12 the difference between the ball of the foot and the center of the foot was around 1 cm. That was interesting to me.
I think binding placement is pretty important since everyone skis a bit different and I have skied on skis in the past that in my opinion were designed with the waist in the wrong spot. Moving the binding made a big difference in finding the sweet spot on that particular ski.

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