Has anybody selected underfoot size based on foot width instead of resort conditions?

[LiquidFeet]

Can you say that in English?

You need to study the video in order to learn the terms used in simple foot/ankle biomechanics of alpine skiing.

Sounds like the answer is "no".

 

[mdf]

the only thing that increased area does is make you go faster, by decreasing how much snow your leg shafts push out of the way (by floating you higher).]

It also averages over more samples in variable snow, reducing the sensed variation.

 

[James]

Interesting vid.
The thing that’s new to me is the blocking of pronation shifting the center of pressure line. I’d like to hear more about this.

I get the sense when skiing wider skis on hard snow you want to throw lower leg inclination at it initially. Can’t just tip the foot and off we go. But that’s playing with 95-100mm. Don’t know foot width, but 27 mondo in narrow last. (Roughly 94mm in 26)
So there’s another question. If your in a wider last comfy wide boot does it influence things over a narrow last, or is it truly just the foot width? Or theoretically, you add 2cm of plastic to the width. Does it change things?

My point is that all the "width" does is change the area underneath the ski, and the only thing that increased area does is make you go faster, by decreasing how much snow your leg shafts push out of the way (by floating you higher).]

Well it also makes possible, do to that float and the ability to go sideways, many more types of maneuvers. You would not do say a slash turn on narrow skis in pow. Or it would be different anyway.

 

[Marker]

My answer is "no" to the OP, but the recent discussion again makes me wonder if height can still play a role as does weight in selecting ski width and length for resort conditions. At 6'6", I have a naturally wider foot (~112 mm) even though I'm in a narrow lasted boot (Lange RS 130 in 30.5) simply because my foot is longer. So I have a wider foot platform to pronate into a turn, and then a longer lever "arm" (femur) to more easily further tip the skis. In the past when I've asked whether this means I can naturally ski wider skis without less stress on my knees, I was told "no", but this thread makes me wonder. I don't ski my Ranger 115's on hardpack, so let's get that out of the way. If I think back to last season, I think I would agree that these skis being wider than my feet "block" their pronation, but I'll have to pay fresh attention this season when I get the opportunity to ski them. I have 88 mm daily drivers and 69 mm cheater GS skis for firm days. Yes, the cheaters are faster to tip, but my 112 mm foot is much wider than the 88 daily drivers, so should I expect them to fatigue my knees less than they would a shorter skier? The answer would seem to be "yes".

 

[Noodler]

My answer is "no" to the OP, but the recent discussion again makes me wonder if height can still play a role as does weight in selecting ski width and length for resort conditions. At 6'6", I have a naturally wider foot (~112 mm) even though I'm in a narrow lasted boot (Lange RS 130 in 30.5) simply because my foot is longer. So I have a wider foot platform to pronate into a turn, and then a longer lever "arm" (femur) to more easily further tip the skis. In the past when I've asked whether this means I can naturally ski wider skis without less stress on my knees, I was told "no", but this thread makes me wonder. I don't ski my Ranger 115's on hardpack, so let's get that out of the way. If I think back to last season, I think I would agree that these skis being wider than my feet "block" their pronation, but I'll have to pay fresh attention this season when I get the opportunity to ski them. I have 88 mm daily drivers and 69 mm cheater GS skis for firm days. Yes, the cheaters are faster to tip, but my 112 mm foot is much wider than the 88 daily drivers, so should I expect them to fatigue my knees less than they would a shorter skier? The answer would seem to be "yes".

Whenever considering questions like these I always find it valuable to inject "extremes" into the scenario to help see the truth. So if we consider the extreme of an extremely big boot on a much larger than average person (almost to the point where the ski is practically a toothpick in comparison), I would hope that everyone would agree that size would indeed change the amount of physical leverage you would have over the ski (both laterally and longitudinally). So my answer would be that you probably do have some advantage at your size to tip and flex the same ski than a much smaller person.

 

[David]

I'm 6' in a 27.5 boot with 118 width feet before adding the liner & shell to that. I ski on 77's, 88's & 104's so all my skis are narrower than my feet. I've had these feet my entire life so I have no idea how their width effects all of this other than I can boot out on every ski I've ever had but I do it a lot less than I did in the 90's.

 

[Seldomski]

The width of the boot doesn't matter (unless it is so large that it is touching the snow). The torque your knee feels is still the same for a particular edge angle and ski width.

Now if your knee itself is really wide, then you would be seeing lower contact stresses in the knee joint in the cartilage - the force couple would be acting on a larger spacing. So maybe with really big, wide knees you can tolerate wider skis better.

 

[Noodler]

The width of the boot doesn't matter (unless it is so large that it is touching the snow). The torque your knee feels is still the same for a particular edge angle and ski width.

Now if your knee itself is really wide, then you would be seeing lower contact stresses in the knee joint in the cartilage - the force couple would be acting on a larger spacing. So maybe with really big, wide knees you can tolerate wider skis better.

You're not fully digesting what considering an extreme provides. If the extreme case provides a change, then any increase/decrease in the amount/level of the variables in question, that are in the range of values moving to that extreme, will also most likely result in a change. If there's no change in the extreme scenario, then you can be assured that there's probably no change, no matter what.

Bigger people, have bigger body parts. So in your example, any increase in knee size would equate to a change in the forces/stresses experienced.

 

[no edge]

My skills fall off on wider skis. Leg alignment and the abiity to use a wider stance creates trouble. 94 is the widest I have enjoyed and the ski was a pretty good one. Kastle FX 94. But, soft snow lessens the problem.

 

[cantunamunch]

My skills fall off on wider skis. Leg alignment and the abiity to use a wider stance creates trouble. 94 is the widest I have enjoyed and the ski was a pretty good one. Kastle FX 94. But, soft snow lessens the problem.

Have you ever tried lifters on 95-100 mm skis?

 

[Doug Briggs]

My skills fall off on wider skis. Leg alignment and the abiity to use a wider stance creates trouble. 94 is the widest I have enjoyed and the ski was a pretty good one. Kastle FX 94. But, soft snow lessens the problem.

A lot.

 

[Doug Briggs]

Have you ever tried lifters on 95-100 mm skis?

My boss at the ski shop, a racer forever, uses lifts on ALL his skis. His widest, I think, are about 95 - 100 mm. Some Kastle FXs IIRC.

 

[no edge]

Have you ever tried lifters on 95-100 mm skis?

I have not, but wouldn't that increase stress at point of contact?

 

[cantunamunch]

I have not, but wouldn't that increase stress at point of contact?

Not sure what you mean by that - sure it could increase the lever arm and increase the torque at the ski - but the premise is that you would be putting the same force on it at your knee as ever.

The major line of argument against lifters on wider skis has been that they decrease sensitivity to tipping the ski. Which, if it's painful for you, you might actually be OK with, no?

Now, if your boot balance is off or if you're trying to twist-steer the ski, or if you have trouble disengaging the turn, then, yes, I can see it being a problem.

 

[no edge]

Not sure. I could see how it could work. Seems like I have to use more force to get the ski on edge, but I am not certain. Also I get the feeling that I am much closer to the snow than with narrower skis. I could try it.

 

[cantunamunch]

Not sure. I could see how it could work. Seems like I have to use more force to get the ski on edge, but I am not certain. Also I get the feeling that I am much closer to the snow than with narrower skis. I could try it.

I think of it as same angle - bigger sweep - same force - longer lever arm. But as Von Braun said, one good test is worth a thousand expert opinions.

 

[no edge]

I think I could try that.

 

[markojp]

Personally, I'd be way more worried about boot fit than foot width, and that's pretty much all I have to say about that.

 

[Henry]

My question is about boot fit, also.

I agree with the observations made in the video, and with most of the conclusions. His diagram at the 1:51 point is clear and to the point. I differ with him on the effect of the sole of the foot on the tilting of the ski. My well fitted boots tilt the skis when I move my leg to an angle. I don't have room to move my foot inside the boot except for some slight flexibility in the footbed to allow for some pronation as the weight progresses from more on the toes at the beginning of the turn to about equal at the end of the turn. I don't tilt my skis with my 1st metatarsal joint--I tilt my skis my the movements of my legs.

If one's boots do not fit like an exoskeleton, if there is slop in them either from a loose fit or from soft shells, then yes, where the 1st met is located relative to the ski's edge may make a difference.

Here is more published by the National Institutes of Health detailing why wide skis on hard snow cause pain: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4541126/

 

[Henry]

I wonder if the creator of the video thinks one edges the outside ski by everting the outside foot? That would lead to what he describes, especially if the boots aren't fitted just right. Don't evert that foot...roll it up on its inside edge. Instead lighten and invert the inside foot (roll it to its outside edge). Keep the outside leg and ankle straight and strong. Tilt the lower body to get the skis up on edge.

Here's Stefano Gross showing how it's done.