# Help me buy men's skis...



## MRGisevil (Nov 27, 2007)

Please won't you help me pick out skis for my husband???






Took Tim out to a couple of ski shops in our area to look at leftovers tonight and found a couple within budget (which is around $400) that he seems to like... was wondering if you gents might tell me what you think.






Found these at our LSS for $350






.

These were on sale at the same store for $399.

Tim is a high intermediate/low advanced skier who likes skiing bumps but not necessarily tight moguls. Likes groomers, doesn't do much out-of-bounding. Wants to go with a shorter ski because his knees have been bugging him over the past few years (Is 6'0/ 185 and looking at 160s).

Do you think this'd fit him well or am I going in entirely the wrong direction here? Any advice would be greatly appreciated.

Thanks guys


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## bvibert (Nov 27, 2007)

160 sounds awfully short for a guy his size to me.  Other than that I have no idea...


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## severine (Nov 27, 2007)

I have no idea how accurate this is, but food for thought... this is a chart with recommendations for length of ski based on weight.  As Trekchick will say, a ski doesn't know how tall you are...only your weight.  But based on the info you've given, I think 160 is too short.
http://www.alpineskicenter.com/skisizes.htm

ETA:  Here's another chart:
http://www.backcountry.com/store/newsletter/s100000025/a232/What-size-ski.html


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## Greg (Nov 27, 2007)

I'm 6'1", 165 lbs., probably middle advanced skier, and I would never go below 170 cm. At 20 lbs. heavier than me I also think 160 cm is way too short. I don't know much about those particular skis but they look pretty radically shaped and probably would hook too much in the bumps. What are the tip/waist/tail dimensions?

You should have him demo skis before committing, although I've bought skis without demoing based on reviews and such and have not been disappointed. Tough to demo the exact ski you want in all conditions you might ever encounter anyway.

What's he skiing on now?


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## MRGisevil (Nov 27, 2007)

Well, the guy at the ski shop told him 170s would be better for his height, but 160s would be much easier on his knees, so that's why we're looking at the shorter ones...any input?

Demoing's a great idea, but don't have the dough to pony out for a new pair this year, so even if he found something he really liked we wouldn't be able to pick them up... or are there sales I just don't know about.

His old skis...I know they are Atomics, but they're also 8 years old and on their way out. 180s and have been giving his knees a hard time... so if anything, probably wouldn't want to go any higher than 170 tops depending on what we do.

Also, the Contact 8 are 123-71-105 but I can't find the dimensions for the Blizzards.


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## Greg (Nov 27, 2007)

Aim for 170-175, more based on his weight than height. He'll be happier on a ski more suited for his size than one he probably will end up over-skiing. At those dimensions, the Contacts are going to be way too hooky in the bumps, but if his knees are hurting him, he probably won't be spending too much time there anyway.

Might sound like a silly question, but what kind of turner is he, mostly? Short quick turns, medium sized turns or fast big turns? It sounds like his preference is mostly groomed trail skiing?


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## skidbump (Nov 27, 2007)

Ok here we go,
230 5'8" ski average 75 days a yr
162 metron b5
167 k2 phat luv
169 movement kamasutra's
176 line prophet 80's


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## Beetlenut (Nov 27, 2007)

MRGisevil said:


> His old skis...I know they are Atomics, but they're also 8 years old and on their way out. 180s and have been giving his knees a hard time... so if anything, probably wouldn't want to go any higher than 170 tops depending on what we do.


 
My two cents...
Two things, Shaped skis have come a long way in eight years, specifically in length. I had a pair of Atomics from 2000 in a 180cm and man were they heavy compaired to the newer models of the past year or two. I think a 170 or maybe a 168 would be as short as he might want to go. 

Width of the ski is another factor, a shorter but fatter ski would distribute his weight better IMO. Also a fatter ski 80mm-90mm in the middle, wouldn't be so squirrely if skiied shorter.

Is Matts Ski Shop still around down on Route 20?

Bill


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## Marc (Nov 27, 2007)

MRGisevil said:


> Well, the guy at the ski shop told him 170s would be better for his height, but 160s would be much easier on his knees, so that's why we're looking at the shorter ones...any input?
> 
> Demoing's a great idea, but don't have the dough to pony out for a new pair this year, so even if he found something he really liked we wouldn't be able to pick them up... or are there sales I just don't know about.
> 
> ...



Right away you can go ahead and disregard what the shop guy told you then.  Ski length should be based only on weight.  The flexed ski is basically a big spring.  The more weight you have, the bigger spring you need.  Just like leaf springs on a truck.... the size of the leaf spring has nothing to do with length or height of the truck, only the weight of the load, right?  Naturally one should fine tune length choice based on the type of ski being bought and the intended use, but weight gives you a good ball park.  I'd go 175-185 cm for his weight, on average.

I tend to question whether the swing weight of the ski is what is putting stress on his knees or if it's his technique.  Perhaps it would be a good idea to find a sports doctor with experience working with ski teams, or an athletic trainer maybe.

In any case, I'd be more concerned with the radius of the ski.  A shorter radius ski requires less torque input from the skier to turn, as it tends to turn on its own when put on edge and flexed.  My advice would be to look for a relatively lightweight ski and keep it to a 15 m sidecut or less.


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## Greg (Nov 27, 2007)

Marc said:


> Ski length should be based only on weight.



I don't know about that. I do agree that weight is most important and any shop that makes a ski length suggestion based solely on height should be questioned. Still, doesn't it seem like a taller skier may be able to leverage a ski more than a similar weighted shorter skier?


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## prisnah (Nov 27, 2007)

He shouldn't be looking at anything under 170 at that weight. He'll outski his gear. When buying skis, always try and buy something that you can progress into a bit. Staying that small is gonna severely limit any progress he might make and completely prevent him from  maintaining any kind of stability at any kind of speed.

Now, I know next to nothing about the types of skis it seems he likes nor have I seen him ski so I wouldn't feel comfortable recommending specific skis. Since it seems neither you nor he really has a definitive feeling about what kind of or size ski suits him I would say he should demo for a bit.

Not only will this allow him to find a ski he likes in a length that works for him, you should also be able to get a MUCH better deal later in the season on newer skis. Or you can  save even more by finding a 06/07 in the same ski on the interwebs. 


And get the hell away from any shop guy who recommends a ski based strictly on height....skis can't feel height, just weight. Which is why I ended up with 165 Blends, but that's a story for another day....although they did work out alright.


Just for reference I'm 5' 7 170lbs and will be skiing on:

179 K2 PE's
179 Bro Models
176 Armada Ar6
165 Line Chronic Blend (rock/urban ski)


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## prisnah (Nov 27, 2007)

Greg said:


> I don't know about that. I do agree that weight is most important and any shop that makes a ski length suggestion based solely on height should be questioned. Still, doesn't it seem like a taller skier may be able to leverage a ski more than a similar weighted shorter skier?



100% on the money IMO. 

Ideally it should be based purely on weight, but if you got a person with an abnormal height/weight ratio you hafta compensate for that.


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## Marc (Nov 27, 2007)

Greg said:


> I don't know about that. I do agree that weight is most important and any shop that makes a ski length suggestion based solely on height should be questioned. Still, doesn't it seem like a taller skier may be able to leverage a ski more than a similar weighted shorter skier?



When do you mean?  And what's the lever arm and pivot point we're talking about?


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## Greg (Nov 27, 2007)

Marc said:


> When do you mean?  And what's the lever arm and pivot point we're talking about?



Don't go getting all technical on me now. I barely passed Physics in college. Just explain it to me. Does height play absolutely no part?

For example, I'm 6'1" and 165 lbs; pretty light for my height. Should a 5'7", 165 lb. skier be on the same length as me?


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## Marc (Nov 27, 2007)

Greg said:


> Don't go getting all technical on me now. I barely passed Physics in college. Just explain it to me. Does height play absolutely no part?
> 
> For example, I'm 6'1" and 165 lbs; pretty light for my height. Should a 5'7", 165 lb. skier be on the same length as me?



From everything anyone's ever told me, and from the simple analysis of forces acting on a skier in my head, 1) no and 2) yes.

And congrats on passing physics, that's a lot more than can be said for a lot of people.  The concepts involved require a lot of effort to understand, especially if you didn't inherit a more analytically oriented mind.

As far as the forces involved in a turn go, height will affect the placement of the center of mass of the skier, and where the skier can move his CM to his advantage to balance the forces induced by the angular acceleration of a turn.  Remember, any time you change velocity, you accelerate, so when you arc through a turn, you're experiencing acceleration.

The force placed on the skier through a turn of like radii is shown by Newton's 2nd law, force is equal to mass times acceleration.  For the same skier making a turn of the same radius, the mass of the skier is accelerated by the same amount, so the skier with the greater mass will experience a greater force, which he will exert back on the snow through his skies (3rd law).

Since it is force on the ski that causes it to deform (deflect), it is only the mass of the skier and the radius of your turn that affects the force on the ski.  In general, a longer ski of the same model is not only scaled up to provide a bigger spring for the bigger force, but also gives more surface edge area that the heavier skier needs to maintain the no slip edge condition.

I think I can make it less technical than that if I need to, but if you passed physics it should make sense, yes?


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## Greg (Nov 27, 2007)

Marc said:


> And congrats on passing physics, that's a lot more than can be said for a lot of people.  The concepts involved require a lot of effort to understand, especially if you didn't inherit a more analytically oriented mind.



Thanks. As a requirement for my Biology degree, passing that class was quite an accomplishment, I guess.



Marc said:


> I think I can make it less technical than that if I need to, but if you passed physics it should make sense, yes?



I did say I barely passed, as in a D. It was also an 8 am class and as a hungover college student that can be brutal. It was also almost 12 years ago and anything I "learned" left this brain within seconds of finishing the final.

Thanks for the explanation though. Some of it might register after I read it about a half dozen more times... :lol:


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## Marc (Nov 27, 2007)

Well, here's another instance that's easier to understand.  Think of skidding down hill, as one often would do skiing moguls.  Assuming that the skier isn't accelerating downhill, merely skidding down hill with constant velocity.  To maintain a steady skidding velocity, the force of gravity pulling the skier down the hill must be balanced by the force of friction generated by the ski edge pushing the skier "up" the hill (in reality just acting against the direction of travel).  Heavier skier means bigger force of gravity, which means he requires a bigger opposing frictional force.  A bigger opposing frictional force can be accomplished by having more ski edge length in contact with the snow, i.e., a longer ski.  Again, height never comes into play here.


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## MRGisevil (Nov 28, 2007)

Well, while my head is still spinning somewhat, I do appreciate all the advice and it makes some good sense. I'm not sure it's bad technique, because up until he took a few years off he was a much better skier than he is today and his knees were bugging him back then too. I think it has to do more with 10++ years of skiing, mountain biking, soccer & mixed martial arts that just took a toll on the poor guy.

I'd say he's a medium turner right now, nothing too wide, but nothing short and fast either at this point. Likes places like Magic where it gets naturally bumped out, but also likes his fair shair of groomers. I'm sure I'm selling him short though, I'm probably not one who should be judging other peoples' techniques. 

I think after hearing this from you all, I'm going to take him out to some demo days (think there's 1 @ Hunter on the 8th?) and then if he finds something he likes try to search for an older model of it. I'd wait until end of season to grab a deal on this year's skis, however, I'd find it a miracle should his current skis happen to wait that long. If I'm going to be taking him out every weekend with me (which is my grand scheme, and he also seems to be ok with this for the time being) I'd like to have him in something a bit more reliable sooner rather than later.

I don't know about any places on Rte 20, so I don't think it's around anymore. There's a place in West Springfield & another in Holyoke but to tell you the truth, I'm not such a fan of either. The owners of both places have used car salesman syndrome and seem to want to stick you on whatever you're willing to pay the most money for (when I was searching for skis I told one of them I had a budget of $400-500 and he immediately redirected me to a group of skis in the 1000 range).

Thanks for the input, everyone  I will throw both of those skis back into the perhaps pile and continue my search.


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## Marc (Nov 28, 2007)

Well, I didn't mean to imply that he had bad technique.  Good carving technique can put a big strain on one's knees.  I just wanted to point out that knee pain, in my opinion, will probably not be alleviated by skiing a shorter ski rather than one that's the correct length for him.


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## SKIQUATTRO (Nov 28, 2007)

i'm 5'10" 180lbs and was fitted on Atomics Metrons at 157cm (upper advanced/exp level).....i demod all the other lengths and the 157 just 'worked'


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## jack97 (Nov 28, 2007)

Marc said:


> As far as the forces involved in a turn go, height will affect the placement of the center of mass of the skier, and where the skier can move his CM to his advantage to balance the forces induced by the angular acceleration of a turn.  Remember, any time you change velocity, you accelerate, so when you arc through a turn, you're experiencing acceleration.
> 
> The force placed on the skier through a turn of like radii is shown by Newton's 2nd law, force is equal to mass times acceleration.  For the same skier making a turn of the same radius, the mass of the skier is accelerated by the same amount, so the skier with the greater mass will experience a greater force, which he will exert back on the snow through his skies (3rd law).
> 
> Since it is force on the ski that causes it to deform (deflect), it is only the mass of the skier and the radius of your turn that affects the force on the ski.  In general, a longer ski of the same model is not only scaled up to provide a bigger spring for the bigger force, but also gives more surface edge area that the heavier skier needs to maintain the no slip edge condition.



Hmm interesting conversation.... from the top of my head, for the same weight, a skier height does come into play. The com is higher but when he/she moves laterally to make a turn, the axis of rotation is further away from the ski. IIRC, the angular forces generated would be greater b/c of the difference in com location, again assume same weight, same speed going into turn, same snow conditions and so on. Thus it would be relatively easier to deform (reverse camber) the ski due to the extra force generated.


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## Marc (Nov 28, 2007)

jack97 said:


> Hmm interesting conversation.... from the top of my head, for the same weight, a skier height does come into play. The com is higher but when he/she moves laterally to make a turn, the axis of rotation is further away from the ski. IIRC, the angular forces generated would be greater b/c of the difference in com location, again assume same weight, same speed going into turn, same snow conditions and so on. Thus it would be relatively easier to deform (reverse camber) the ski due to the extra force generated.



Well, the problem is a lot more detailed then my inital response to Greg would lead on.  Height does play a factor in the placement of a skier's CM, which certainly has the potential to affect the force on the ski, but in my estimation, does not make enough of a difference (or any at all) to matter when choosing the length of a ski.  I'll draw it out so it's easier to discuss...


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## Marc (Nov 28, 2007)

Above we have a crude drawing of the forces acting on a skier, let's say, mid way through a carved turn.

The blue angled line represents the outside ski, inside ski not shown for simplicity's sake and the fact that much more force is typically applied to the outside ski during a turn.

CM1 represents center mass for a tall skier, CM2 represent center mass from a shorter skier, both of the same mass.  The blue line marked AOR is the axis of rotation of the carved turn (approximating a circular radius if viewed from above).

Now the forces- the horizontal green arrow represents the centripetal force applied by the snow on the skier accelerating him through the turn.  The vertical green arrow represents the reaction force of the ground pushing against the skiers weight, which is the same in both instances.  The two black vertical arrows represent the force of gravity acting on the skiers' respective center masses.  The horizontal black arrows represent the reaction force, "centrifugal" force, to the centripetal acceleration, which act on the skiers' respective center masses.  The black angled force pointing on the ski is the result of the vector sum of the forces acting on the skier's CM and applied at this point.  This is the force that loads the ski.

Now for torques acting on the skier, which must balance, otherwise the skier goes tumbling off tangential to the turn.  All moment arms are represented by the double ended red arrows.  Negative (counterclockwise) torque is generated by the centrifugal force acting on a moment arm that has a length equal to the height of the skier's CM from the ground.  This torque is balanced by the skier bringing his CM closer to the AOR, and creating a moment arm on which the weight of the skier acts (lateral distance from the dashed red line to the CM of the skier).  This generates postivie torque, to balance the negative.

The last element of the equation - the limit of adhesion of the ski.  This is generated by the frictional force of the ski digging into the snow, which is proportional to the weight of the skier, which in this case, is the same.

Now let's assume they are tracking through a turn of the same radius (meaning ski to AOR).  They both lean over to get the ski on edge to generate frictional force and to generate that positive torque.   The centripetal force generated is proportional to lateral distance from CM to AOR.  It first glance, it looks like the taller skier can keep his mass closer to the AOR and thereforce reduce the centripital force generated and therefore the force on the ski.

However, if you'll look at the diagram, there's an imbalance on torque on the taller skier.  As he leans over moving his CM closer to the AOR, the centripital force is less, however it is acting on a larger moment arm due to his height.  The shorter skier generates more centripital force, however this has a smaller moment arm to act on due to the height of the skier.  So the two "centripital torques" are close to equal (not everything scales linearly, but pretty close).  This means the taller skier of the same weight, by leaning over to generate less centripetal force ends up giving more moment arm to his weight, which means he is generating more positive torque than the shorter skier.  To compensate, and to keep from falling over, the taller skier must bend his legs, and reduce that moment arm.  To balance, he then moves his center of mass to where the shorter skier's is, and thus the applied force on the ski is still about the same.

This would only increase or decrease significantly if you changed the weight of the skier.


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## Greg (Nov 28, 2007)

My head just exploded. I'm outta this one... :blink:


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## severine (Nov 28, 2007)

OMG, it's just like talking to my cousin.  Who was an engineer (although he recently switched professions to becoming a patent lawyer).  I could totally see him diagram his argument in a discussion.


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## Greg (Nov 28, 2007)

Marc - I have to know. Is all this stuff off the top of your head, or do you have Wikipedia or something fired up in another browser? If the former, then I think it's quite possible you are an alien.


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## Marc (Nov 28, 2007)

Greg said:


> Marc - I have to know. Is all this stuff off the top of your head, or do you have Wikipedia or something fired up in another browser? If the former, then I think it's quite possible you are an alien.



Nope, that's all in my head.  It's easy, just identify and balances the forces and torques


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## MRGisevil (Nov 28, 2007)

Marc said:


> Nope, that's all in my head.  It's easy, just identify and balances the forces and torques



I work with Engineers all day. I can vouch for all of that being as common knowledge to him as shoe tieing is to the rest of us.


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## Marc (Nov 28, 2007)

MRGisevil said:


> I work with Engineers all day. I can vouch for all of that being as common knowledge to him as shoe tieing is to the rest of us.



Oh man, and you shoulda seen the last time I tried to tie my shoes on my own.  What a disaster.


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## jack97 (Nov 28, 2007)

Marc said:


> Now for torques acting on the skier, which must balance, otherwise the skier goes tumbling off tangential to the turn.



I have thinks about this one, I would agree that there is a critical angle that the ski edge has to take else one would tumble over. I think there are more parameters to this. 



Marc said:


> However, if you'll look at the diagram, there's an imbalance on torque on the taller skier.  As he leans over moving his CM closer to the AOR, the centripital force is less, however it is acting on a larger moment arm due to his height.




Hmm, ok I got it, the centripital force would be lower for the taller skier since there is less mass at the radius of rotation. And it would be roughly the same for the tall and short skier. 

But I beleive that the conservation of angular momentum does favors the taller skier.... still have to think one through.


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## Marc (Nov 28, 2007)

jack97 said:


> I have thinks about this one, I would agree that there is a critical angle that the ski edge has to take else one would tumble over. I think there are more parameters to this.



It's simplified, but a decently accurate representation of the forces involved in a carved turn.  One could look a little closer at the geometry of the ski but it wouldn't tell you anything about the input force from the skier, which is based on the centripetal force generated and the weight of the skier.



jack97 said:


> Hmm, ok I got it, the centripital force would be lower for the taller skier since there is less mass at the radius of rotation. And it would be roughly the same for the tall and short skier.
> 
> But I beleive that the conservation of angular momentum does favors the taller skier.... still have to think one through.



Well, the point I was trying to make is that the CM is not a static location for either skier.  It could potentially be closer to the axis of rotation for a taller skier resulting in a smaller radius to the CM and smaller centripetal force, but to do so he would require some aid to keep him from rotating down to the snow, otherwise he must flex his legs and bring his weight closer to his skis to balance the torques acting on him.


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## Grassi21 (Nov 28, 2007)

Marc scares me.....  All those deviate behaviors and he is smart.  Lethal combo.  

Back on topic and sorry to hijack MRGs thread...  This short stocky italian is looking at some AC 30s at 170 in length.  I'm just under 5'8" and tipping the scales at 200 lbs (desperately fighting to get down between 185 and 190).  Would these work out for me?


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## jack97 (Nov 28, 2007)

Marc said:


> It's simplified, but a decently accurate representation of the forces involved in a carved turn.  One could look a little closer at the geometry of the ski but it wouldn't tell you anything about the input force from the skier, which is based on the centripetal force generated and the weight of the skier.
> 
> 
> 
> Well, the point I was trying to make is that the CM is not a static location for either skier.  It could potentially be closer to the axis of rotation for a taller skier resulting in a smaller radius to the CM and smaller centripetal force, but to do so he would require some aid to keep him from rotating down to the snow, otherwise he must flex his legs and bring his weight closer to his skis to balance the torques acting on him.




OK, say the critical angle, centripedal force is a wash for both tall and short skier. However, one still has to take into account that angular velocity does change as the com moves along the radius from the axis of rotation. Only way you can explain "pumping" in any angular movement to increase speed. The taller skier will have this advantage since he/she has more range.


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## Greg (Nov 28, 2007)

Grassi21 said:


> Back on topic and sorry to hijack MRGs thread...  This short stocky italian is looking at some AC 30s at 170 in length.  I'm just under 5'8" and tipping the scales at 200 lbs (desperately fighting to get down between 185 and 190).  Would these work out for me?



I would say it's a good length. I haven't skied the AC30, but the 2005 AC3 is a lot of ski. Knowing your ability, it might be a tad too demanding (keeping it real). With my AC3, you can't be passive when skiing it; you need to be actively riding the ski or it's going to throw you. An AC20 might be a more appropriate next step? In fact the AC20 dimensions are closer to the old AC3 so it's probably still a lot of ski and something that you can grow into.

http://www.volkl.com/ski/unlimited_ac20.html


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## Grassi21 (Nov 28, 2007)

Greg said:


> I would say it's a good length. I haven't skied the AC30, but the 2005 AC3 is a lot of ski. Knowing your ability, it might be a tad too demanding (keeping it real). With my AC3, you can't be passive when skiing it; you need to be actively riding the ski or it's going to throw you. An AC20 might be a more appropriate next step? In fact the AC20 dimensions are closer to the old AC3 so it's probably still a lot of ski and something that you can grow into.
> 
> http://www.volkl.com/ski/unlimited_ac20.html



I'm all about keeping it real.  

The rep at my local shop has been steering me towards the AC30.  Maybe because they don't have any AC 20s in stock.  ;-)  I would lean towards your assessment since you have skied with me while the rep has not.  The 30s are 80 something underfoot which is why I was leaning towards them.  The 20s as you know from that link you posted are 74 underfoot.  I'm going to do my best to find a place to demo them.  Not pulling the trigger until after the X-Mas.  I love gift cards.


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## wa-loaf (Nov 28, 2007)

Grassi21 said:


> I'm all about keeping it real.
> 
> The rep at my local shop has been steering me towards the AC30.  Maybe because they don't have any AC 20s in stock.  ;-)  I would lean towards your assessment since you have skied with me while the rep has not.  The 30s are 80 something underfoot which is why I was leaning towards them.  The 20s as you know from that link you posted are 74 underfoot.  I'm going to do my best to find a place to demo them.  Not pulling the trigger until after the X-Mas.  I love gift cards.



Do you guys have similar boot soles? Maybe you can test drive Gregs AC3s?


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## Grassi21 (Nov 28, 2007)

Grassi21 said:


> I'm all about keeping it real.
> 
> The rep at my local shop has been steering me towards the AC30.  Maybe because they don't have any AC 20s in stock.  ;-)  I would lean towards your assessment since you have skied with me while the rep has not.  The 30s are 80 something underfoot which is why I was leaning towards them.  The 20s as you know from that link you posted are 74 underfoot.  I'm going to do my best to find a place to demo them.  Not pulling the trigger until after the X-Mas.  I love gift cards.



Scratch that.  The difference underfoot is just 2.


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## Greg (Nov 28, 2007)

Grassi21 said:


> I'm all about keeping it real.
> 
> The rep at my local shop has been steering me towards the AC30.  Maybe because they don't have any AC 20s in stock.  ;-)  I would lean towards your assessment since you have skied with me while the rep has not.  The 30s are 80 something underfoot which is why I was leaning towards them.  The 20s as you know from that link you posted are 74 underfoot.  I'm going to do my best to find a place to demo them.  Not pulling the trigger until after the X-Mas.  I love gift cards.



The AC30 is 76mm at the waist, I believe. If you're looking for something a bit wider under foot but still forgiving, maybe think about a Rossi B2? I've never ridden one, but it seems like it's the generic mid-fat for the upper intermediate skier. Probably a good one to consider for MRG's husband as well.


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## Grassi21 (Nov 28, 2007)

Greg said:


> The AC30 is 76mm at the waist, I believe. If you're looking for something a bit wider under foot but still forgiving, maybe think about a Rossi B2? I've never ridden one, but it seems like it's the generic mid-fat for the upper intermediate skier. Probably a good one to consider for MRG's husband as well.



I like how your brought things right back on topic.  ;-)  This guy is good.


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## Greg (Nov 28, 2007)

Grassi21 said:


> I like how your brought things right back on topic.  ;-)  This guy is good.



Years of experience... :razz:


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## campgottagopee (Nov 28, 2007)

Holly crap---a lot of mumble jumble in this thread---here's my .02 simply put.....
Buy him something that is in the "all mountain cruiser" catagory. You can't go wrong, I promise. These types of skis are just what the claim to be---good at everything. You can ski bumps, groomers, hard-n-soft snow, trees, steeps etc.
As for height, weight vs. length of ski, well, that's all crap. Just look at World Cup skiers. You've have some seriously big/strong dudes rippin it on 160's, why, well because of how stiff the ski is torsionally. That's what will allow someone who's bigger ski a shorter ski. I'm 6'4", 250 lbs and ski 178's (nordica top-fuel) thats 123-78-108 w/r18. I've skied the nordica world cup doberman slalom ski at 155. Very, very, very stable but you needed to be on edge at all times---not the type of skiing I like to do.
Anyway, hope that helps. Remeber, just look for all-mountain cruiser/expert catagory and you'll be good.


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## jack97 (Nov 28, 2007)

damn that was fun. I don't get a chance to talk physical mechanics all the time. It's mostly electro mechanics and statistical analysis.....


Yeah, they got the big boys on short skis, but thats for slalom events. IIRC they will start enforcing a minimum length rule along with sidecut restrictions for that event. For the GS and down hill events they have them longer.


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## campgottagopee (Nov 28, 2007)

jack97 said:


> damn that was fun. I don't get a chance to talk physical mechanics all the time. It's mostly electro mechanics and statistical analysis.....
> 
> 
> Yeah, they got the big boys on short skis, but thats for slalom events. IIRC they will start enforcing a minimum length rule along with sidecut restrictions for that event. For the GS and down hill events they have them longer.



Glad you guys were having fun...you guys share slide rules or do each of you have you own:razz:

Yes, for GS & DH the skis are much longer because you want them flat and not on edge. Speed baby---it's all about the speed


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## jack97 (Nov 28, 2007)

campgottagopee said:


> Glad you guys were having fun...you guys share slide rules or do each of you have you own:razz:



Sliderules????   It's PCs nowadays, last person who I share my files with.... I ended up marrying her :blink:


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## campgottagopee (Nov 28, 2007)

jack97 said:


> Sliderules????   It's PCs nowadays, last person who I share my files with.... I ended up marrying her :blink:



My bad---I should've known:-o


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## Marc (Nov 29, 2007)

jack97 said:


> damn that was fun. I don't get a chance to talk physical mechanics all the time. It's mostly electro mechanics and statistical analysis.....



:beer:

Anytime you're game I am.  It's good to have someone to bounce ideas off of when you're figuring this stuff out.


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## awf170 (Nov 29, 2007)

Back to dork conversation:

Marc, how about forward and backwards motion of the skier? (Skiing too far in the backseat or too far forward)  If I get way in the backseat my CM is going to be way further back then a skier of the same weight but different height.  Thus causing me to have more torque on the ski.  Also, when leaning forward, it will make it easier to over-flex the ski.  (Though that probably means you would need a stiffer, not longer ski)


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## Greg (Nov 29, 2007)

awf170 said:


> Back to dork conversation:
> 
> Marc, how about forward and backwards motion of the skier? (Skiing too far in the backseat or too far forward)  If I get way in the backseat my CM is going to be way further back then a skier of the same weight but different height.  Thus causing me to have more torque on the ski.  Also, when leaning forward, it will make it easier to over-flex the ski.  (Though that probably means you would need a stiffer, not longer ski)



I was going to bring up fore/aft movement of the skier, but this thread sorta has me frightened.


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## MRGisevil (Nov 29, 2007)

Greg said:


> I was going to bring up fore/aft movement of the skier, but this thread sorta has me frightened.



word x.x


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## Paul (Nov 29, 2007)

MRGisevil said:


> word x.x



Jeez, Randi, something about the threads you start that turn into....um....well, they're different....


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## Greg (Nov 29, 2007)

Paul said:


> Jeez, Randi, something about the threads you start that turn into....um....well, they're different....



Ironically it started shortly after she posted her profile picture a few weeks ago...


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## MRGisevil (Nov 29, 2007)

Paul said:


> Jeez, Randi, something about the threads you start that turn into....um....well, they're different....




ya rly....

But on a serious note, Tim did go through this post and read everyone's responses and it answered a lot of his questions for him, so thanks for being so crazy guys :razz:


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## Paul (Nov 29, 2007)

MRGisevil said:


> ya rly....
> 
> But on a serious note, Tim did go through this post and read everyone's responses and it answered a lot of his questions for him, so thanks for being so crazy guys :razz:



Oh sh*t.... he reads posts here?



Jeebus, I hope my wife doesn't. :-o:lol:


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## Grassi21 (Nov 29, 2007)

Paul said:


> Oh sh*t.... he reads posts here?
> 
> 
> 
> Jeebus, I hope my wife doesn't. :-o:lol:



Forget the wife.  I hope my boss doesn't.  I've sent her a few links about Mt Snow related stuff.  Her fiance has a house up there.


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## bvibert (Nov 29, 2007)

Grassi21 said:


> Forget the wife.  I hope my boss doesn't.  I've sent her a few links about Mt Snow related stuff.  Her fiance has a house up there.



I've been very careful to never mention AZ anywhere near the vicinity of anyone I work with...


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## Paul (Nov 29, 2007)

bvibert said:


> I've been very careful to never mention AZ anywhere near the vicinity of anyone I work with...



Totally, its bad enough having to work with the effers...


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## Marc (Nov 29, 2007)

awf170 said:


> Back to dork conversation:
> 
> Marc, how about forward and backwards motion of the skier? (Skiing too far in the backseat or too far forward)  If I get way in the backseat my CM is going to be way further back then a skier of the same weight but different height.  Thus causing me to have more torque on the ski.  Also, when leaning forward, it will make it easier to over-flex the ski.  (Though that probably means you would need a stiffer, not longer ski)



No, all it means is you need to ski balanced.

That's actually a good point, one I hadn't considered... but just running some quick numbers here-

Even if you have an entire foot on someone that weighs the same as you... your CM is only about 2/3 of your height.  So you're down to an 8" difference.  The perpendicular distance of the effective moment arm in a fore/aft imbalance.... we're talking a lean of maybe 60 degrees... 55 at the most under normal skiing conditions.... about a 4" difference.  If you're 6 feet tall, then your lever arm in such an instance would be three feet.  That means taking off a foot of someone's height only changes the lever arm a little more than 10%.  Said another way, this would be the difference in exerted torque of someone the same height as you that weighed 120 lbs instead of 135.  Considering this a less than desirable instance, and the striking similarity of force exerted through a turn of skiers the same weight and different height, I'll stick with my original position that there's no need to factor height in when selecting ski length.


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