 Poster: A snowHead
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This one will draw Parlor out of the woodwork.
The dangers of using skis that are wider than your skiboots outer dimensions. Descuss. 
Excessive force on bindings and knees. Each mm causing huge amounts of extra torque.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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No, knees are wrecked by narrow-waist skis that carve aggressively when falling, with the skier in the back seat.
Check out the work of Ettlinger, Johnson and Shealy.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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The Abominable snowHead, You're a bright chap try thinking a little for yourself.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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Phew, at first I thought the thread was about me!.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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oh Ski's I thought it said SKiers
I must admit I like a narrower ski, that makes me a bit of a relic nowadays.
Then again I dont do off piste, only when I miss the edge markers 
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You'll need to Register first of course.
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| SMALLZOOKEEPER wrote: |
| The Abominable snowHead, You're a bright chap try thinking a little for yourself. |
Here's a thought, then: if the torque to the knees was increased by a wider ski then the width of the ski would be a factor in calculating the DIN setting of the bindings.
Which it isn't. The length of the boot sole is, though.
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The Abominable snowHead, Exactly my thoughts, it should be. Skis wider thann boots are a fairly new concept. Thankx for staying on track. This is a test easily proved with a packet of cigarettes and a box of matches. Firstly useing the cig box as the boot and the matches to represent the width of the ski. Different combinations of width of boxes on top of each other show my point. Put the cigs box flat on it's back then place the match box sand side down on the middle of the cigs. Place your finger on top of the matches and roll from side to side as if edging, very little effect on the ski? Imagine the torque on the binding if there were one between the two boxes, try using double sided tape between the two boxes. The match box tears away without any effect on the cig box. 
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SMALLZOOKEEPER, AFAIK though that torque that you are talking about (  ) is in the wrong axis for a severe knee injury. The bad torque is one that leads to rotation of the lower leg in comparison to the femur, which I'm not sure will be affected very much by ski width.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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I think Kramer's right: the danger to the knee arises from the lower and upper leg twisting from each other, plus (I think) the support of the back of the boot blocking the natural collapse of the lower leg as the skier falls backwards - so the femur tries to separate from the lower leg.
With a wide ski there's much less turning and carving effect of the ski, so I think the twisting of the leg is reduced rather than increased. Knee injuries have become a modern phenomenon in skiing because of plastic boots and skis that carve better.
SZK, I don't smoke, but if you can lend me the cig box I can do your experiment. Would be more interested in hearing the views of a ski bindings/injuries researcher though.
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Kramer, The Knee thing seems to be very true, those we have whom ski larger than boot width are upping din and suffering lateral knee pain. Geometry seems simple to me and torque tests are proving conclusive. The same tests are being employed as the ones for binding height and ski boot height under FIS regualations.
I think your point about lower leg-femur relations are valid if gait is in effect. As the binding controls lateral force introduced by the knee, resistance within the boot, coller height has a massive effect on lateral forces at knee level
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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My knees have always been a concern to me. I've badly damaged an ACL in one knee (no surgery yet), torn medial ligaments in both knees and have a golf ball size lump of muscle on my inner thigh from having torn several muscles. This winter my knees have been very strong and given me no issues at all. That's after skiing mainly on my Prophets (155/130/148). At this point in the season my whole body aches, least of all, and normally the sorest, are my knees. Perhaps I'm getting more graceful as I get older  I've skied harder this year than ever before. Having hiked the Mont Gele three times yesterday with no trouble, I'm gonna say twaddle to fat skis being unhealthy.
And then I'll think about it for a while.
There's some sense in that there geometry. The Prophets have got quite a shovel on them and there are times (cement / crunchy crud) when the you need to really push that bad boy through the snow, thus increasing the forces on the knees. In truth, I really haven't noticed any additional pain from skiing.
I've been thinking for a while how much easier I find skiing bumps now, in terms of technique and energy expediture. Less knee movement is required for me to swing from the pivot of my mogul turn to find the ski edge as I descend into the trough of the mogul. This makes sense to me, I just wish I could find a better way to describe the action. Perhaps this reduced force is making up for the increased forces on my knees...
I have actually had this discussion this winter with a friend who has pulled the toe piece off Gotamas, twice. He believes that is is increased force from skiing wider skis. I'm not going to deny that there is something in it and be intersting to think / talk some more about it. In the mean time. Snowballs. Fat is beautiful.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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Let's face it, skis wider than your boots are just a generally bad idea. As are skis any shorter than hand above head height. One day normal service will resume.
SZK, I'm sorry, we had a lovely day on Grand Envers yesterday but were hampered by skiing some generally hideous Salomon skis. At some point I will come in for a chat.
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It seems to me, that as the wider ski has more leverage on the binding the ski is going to get pulled off more often when one gets a bit out of shape, especially as the ski is likely to be used in deeper snow. However, the leverage is created by the snow, not the ski, and these skis are more likely to keep a skier near the surface, where snow exerts less force. This means that most of the time the problem is self remedying. (This makes sense to me, but then I have O-levels and A-levels and OLOGIES (albe-em 23 years out of date) coming out of my orifaces .
The problem only becomes a problem when you have a skier regularly getting out of shape, and losing skis. This skier may resort to upping his/her DIN settings, and therefore transferring extra load to the leg, thus resulting in injuries. The skier should not increase DIN because of the extra width, but should work out what he/she was doing wrong in the first place.
My recommendation is that extra width should not be used to calculate an increase in DIN. If the DIN is set the same as for a narrow ski, which comes off without injury, then the wider ski exerting higher leverage will come off quicker, but at the point of breaking free will still be exerting the same force as the narrow ski, required to break free at that DIN setting. Decreasing DIN, to compensate for extra leverage of wide skis, just means the skis will come off even easier, probably at times when a recovery was likely.
Conclusion: extra width changes nothing, unless one tampers with the recommended settings.
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You know it makes sense.
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Imagine a triangle wide at its base, the wider the base the more difficult it would be to topple it over its angle.
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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What about monoskis, or Alpine snowboards?
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Poster: A snowHead
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pam w, Compensated by a single interface and different distribution of lateral force.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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SMALLZOOKEEPER, the pivot is assumed under the centerline of the ski? Underbinding plate height increase proportional to increase in waist dimension. Give the knee a longer lever.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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comprex, Won't get any of the guys out here on a plate, they want to 'on the ski', however, what would be the equasion for finding correct plate height, over boot width, over ski width.
P.S. Still working on your Ad-Ab-ducted boot mod', i'm so tired, lost my wallet, keys and coat all in one week.
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You need to Login to know who's really who.
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| Nick_C wrote: |
I must admit I like a narrower ski, that makes me a bit of a relic nowadays.
Then again I dont do off piste, only when I miss the edge markers :P |
I ski a 65mm waist ski and I only ski "off-piste".
Regarding DIN settings beeryletcher seems to have it about right to me. The DIN setting is the force needed to release a boot from the binding. Obviously the higher the setting the more strain is put onto bones, joints, ligaments etc. That said there are allowances made for fat skiers (etc. to prevent prerelease) so maybe allowances need to be made for fat skis but if that is the case you shouldn't ski a ski fatter than your legs can handle.
Last edited by You need to Login to know who's really who. on Sun 16-04-06 9:33; edited 1 time in total
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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You'll need to Register first of course.
You'll need to Register first of course.
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| slikedges wrote: |
| NB this may be slightly out of context as I orig posted this in another thread :-D |
A bit off topic by I understand that the official scale only goes from 1-10 and that bindings with higher DINS are extrapolations by manufacturers from that scale?
I'm also told that some bindings, if you crank them up to their max DIN, crank them down again they won't ever reach their max DIN (I'm told this is the case for the Naxo NX01 touring binding). However for that to be true it would imply that the springs are being tensioned beyond Young's modulus, which seems like a design error in the binding to me?
Anyway, enough already, there is 30cm of fresh snow above 1900m today.
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As best I can tell ski waist sizes in the US are increasing proportionally to the waist sizes of the skiers. At the rate things are going 100mm skis will be the norm within a decade.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| Rio wrote: |
| As best I can tell ski waist sizes in the US are increasing proportionally to the waist sizes of the skiers. At the rate things are going 100mm skis will be the norm within a decade. |
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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SMALLZOOKEEPER, I ask about the assumed pivot point to slightly elaborate the answer to pam w: if the edge is the assumed pivot point, then a monoskier's bindings might actually be quite close to being just above it.
Edit: whatever happened to offset binding mounts, as in the Powder Plus era?
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PS, forgot to ask whether you'd noticed any problems at the binding screws.
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