Perfect New England tree ski

[bobbutts]

Good advice. Honestly I'm really not. I just find the discussion interesting. The reality is that I don't believe that any of these things make a whole lot of difference. It boils down to the skier much more than the skis. Guys were skiing Dodge's Drop on wooden skis with leather boots back in the day. But it's fun talking through the design process. And I can't wait to get out there on something that I had a hand in building locally!!

BTW, I already own the perfect New England Tree ski: It's 163cm long, 255mm underfoot, dual camber profile, sidecut radius of 7.9 m.....and you stand sideways on it.

Ding Ding Ding!

 

[MadMadWorld]

^ if I remember correctly, the last runout I was on with you, I rode out fine and you came out limping with a helmet full of snow.

I forgot about that.....dammit. Well played sir

 

[BenedictGomez]

Line Sir Francis Bacons====Done and Perfect :razz: LOL

I actually think rocker will be a disadvantage in the trees, my thought is to have some camber with a twin tip early rise tip and tail. I feel that with a full rocker you would be limited in turning ability especially when things get tracked out. I think having a relatively soft ski would be a plus as well, something that you could yes smear a turning with quickly to dump speed. Large early rise shovel in the front, with a narrow early rise tail in the rear. I think 100 under foot would be a solid ski, skiing my Bacons at 115 under foot can get a little overwhelming at times when things get tight, hard to quickly pivot them around.

That's funny, because I've heard others claim the SFB are fantastic eastern tree skis.

thank you I never thought to describe that way.

Going back to OP design....
I think sidecut radius at 14 m it's little aggressive for intended purpose. IMO dimensions should be 132 105 122 with turning radius of
17 m as a comparison MR100 130 100 115 R 18m 178cm

What is your logic here?

The "radius debate" when discussing eastern tree skis is my biggest confusion, because the currently accepted logic is that a small turn radius is better/best in tight trees. That said, I do not for the life of me understand this, because I wouldnt think you'd have the real estate for this to even matter. So.........where am I going wrong with my thinking?

 

[Scruffy]

That's funny, because I've heard others claim the SFB are fantastic eastern tree skis.



What is your logic here?

The "radius debate" when discussing eastern tree skis is my biggest confusion, because the currently accepted logic is that a small turn radius is better/best in tight trees. That said, I do not for the life of me understand this, because I wouldnt think you'd have the real estate for this to even matter. So.........where am I going wrong with my thinking?

Yeah, it's not like you're going to be carving in the trees. That said - Radius comes into play not just for pure carving. There is always self-steering that happens when skis are skidded. In a skid, with the ski on any edge angle (not completely flat), as the snow builds up under the shovel, the shovel bites and creates more edge angle, and as the skiers weight de-cambers the ski, the front of the ski is flexed and angled more than the mid-section and tail, a torque is created and the ski self steers. The shorter the radius the ski is designed to turn in, the quicker the turn even in a skidded turn, via self steering. So, when you are flying through the trees and whip around one and need to execute a very quick turn to save your bacon because there is another tree right there you didn't see, put your skis on edge fast and jamb the shovel into a skid and let the ski self steer. The shorter the radius the quicker they will react.

 

[Abubob]

I've been sort of lurking on this thread as it's been of interest to me since I just purchased in July what would essentially be my tree skis. That is the Dynastar Lengends 172 length and a 132-94-118 sidecut with an "early rise" rocker tip and sort of a semi twin tail. Also these skis have two layers of titanal which I've noticed folks here a against any metal layers.

I haven't been able to offer any further insight until now...

The "radius debate" when discussing eastern tree skis is my biggest confusion, because the currently accepted logic is that a small turn radius is better/best in tight trees. That said, I do not for the life of me understand this, because I wouldnt think you'd have the real estate for this to even matter. So.........where am I going wrong with my thinking?

If you carve for even an instant it can make a difference. What many don't realize is that originally slalom racing was mimicking tree skiing. So slalom skis have nearly always been a shorter ski with more flex to allow a shorter radius turn as opposed to GS or especially a DH ski. The tighter the gates or trees the shorter the radius turn desired.

Another point that I think some folks here are confused on is the use of "camber". Camber does not refer to side cut but the spring load of a ski. (Think of a single leaf of a leaf spring.) Too much camber and you'd never be able to carve and would the ski would tend to burrow or submarine in deep snow. Too much rocker would also be a problem with carving in packed snow because there'd be no ski contact on the tip or tail. That's not to say that a cambered ski can't have a soft flex to allow either a short radius turn or an early rise. Any thoughts on this?

 

[BenedictGomez]

What many don't realize is that originally slalom racing was mimicking tree skiing. So slalom skis have nearly always been a shorter ski with more flex to allow a shorter radius turn as opposed to GS or especially a DH ski. The tighter the gates or trees the shorter the radius turn desired.

The length thing doesn't surprise me at all. In fact, I imagine a slalom ski would be fantastic in tracked out (been a while since it's snowed) woods. There's no doubt going somewhat shorter than the daily driver is beneficial in the woods, and comments to the contrary are either born out of macho bravado ("it's not the tools dude, it's the pilot. I take my 215cm downhill skis into tight trees in 20 inches of fresh powder and KILL it!) or an ignorance of physics. But how much shorter? I don't know. You can obviously go too short, and then you lose stability, which is a very bad thing while skiing immoveable, hard objects like trees and rocks.


But the sidecut on slalom skis is typically in the 60s, and that's the primary reason for their short turn radius, and that's not good for skiing in the woods as they'll submarine constantly. So IMO I'm still looking for answers to the why a short turn radius question. In other words, if we want the 90cm to 110cm underfoot for off-piste trees, AND a short turn radius, then dont we need a pretty fat shovel and likely a fat tail? And all that added material from the larger surface area adds weight, which is another challenge since we want lighter skis for snappy turns.

 

[Scruffy]

But the sidecut on slalom skis is typically in the 60s, and that's the primary reason for their short turn radius, and that's not good for skiing in the woods as they'll submarine constantly. So IMO I'm still looking for answers to the why a short turn radius question. In other words, if we want the 90cm to 110cm underfoot for off-piste trees, AND a short turn radius, then dont we need a pretty fat shovel and likely a fat tail? And all that added material from the larger surface area adds weight, which is another challenge since we want lighter skis for snappy turns.

I gave you the answer above. Get The Physics Of Skiing and read it of you don't believe me. Or get one of Ron LeMaters books.
Or Google the Physics of Skiing.

As far as light, wide, and low teens side-cut, they are all the rage now. You can't swing a cat without hitting one. Look at Dynastar cham HM series.

 

[Abubob]

I gave you the answer above. Get The Physics Of Skiing and read it of you don't believe me. Or get one of Ron LeMaters books.
Or Google the Physics of Skiing.

As far as light, wide, and low teens side-cut, they are all the rage now. You can't swing a cat without hitting one. Look at Dynastar cham HM series.

That book (Physics of Skiing) was published in 2002 so I would think not much is mentioned about rocker. Might it mention "reverse camber"?

 

[Scruffy]

Another point that I think some folks here are confused on is the use of "camber". Camber does not refer to side cut but the spring load of a ski. (Think of a single leaf of a leaf spring.) Too much camber and you'd never be able to carve and would the ski would tend to burrow or submarine in deep snow. Too much rocker would also be a problem with carving in packed snow because there'd be no ski contact on the tip or tail. That's not to say that a cambered ski can't have a soft flex to allow either a short radius turn or an early rise. Any thoughts on this?

I doubt if anyone on this board is confusing camber with side-cut, that's pretty basic. The only reason you would worry about too much camber is if you were skiing down hill on XC skis. The discussion of camber for XC skis, and XC-downhill and that classification of backcountry skis, has little or nothing to do with single camber alpine skis that the peps of this board know and love.

All single camber alpine skis ( that would be all alpine skis until the recent designs of some skis - full rocker and no camber - clown shoes ) are designed to be de-cambered by the opposite forces working against the ski from the snow and human input. The more you de-camber the tighter the turn radius. Softer skis can make it easier to de-camber, but typically suffer at torsional stiffness desired for speed - but not needed for trees. The flex pattern and stiffness are all part of the design, so yeah they make they soft and even with early tip rise.

 

[Scruffy]

That book (Physics of Skiing) was published in 2002 so I would think not much is mentioned about rocker. Might it mention "reverse camber"?

Be careful with the term "rocker", not all skis with rocker are clown shoes. Rocker can mean any and everything to ski manufacture and they use it. Most skis with rocker still have single camber.

 

[Hawkshot99]

But the sidecut on slalom skis is typically in the 60s, and that's the primary reason for their short turn radius, and that's not good for skiing in the woods as they'll submarine constantly. So IMO I'm still looking for answers to the why a short turn radius question. In other words, if we want the 90cm to 110cm underfoot for off-piste trees, AND a short turn radius, then dont we need a pretty fat shovel and likely a fat tail? And all that added material from the larger surface area adds weight, which is another challenge since we want lighter skis for snappy turns.

Waist width is part of a skis dimensions. They do not make up the radius however.

I have 3 pairs of skis, with waists ranging from 71-107mm and the radius don't change a ton.

Fischer Rc4 - 71mm - 17m radius
Volkl Kendo - 89mm - 22m
Rossi Soul 7 - 107mm - 17m

So there is a 36mm diffence between the Rossi and Fischer, but only a 1m difference for the radius, and the fat ski is smaller at that.

 

[Abubob]

This should explain everything:

 

[BenedictGomez]

I gave you the answer above.

You're referring to skidding. Maybe I'm wrong, but conceptually, it seems to me that the relationship with the geometric math involved in turn radius is broken when we talk about skidding rather than carving.

As far as light, wide, and low teens side-cut, they are all the rage now. You can't swing a cat without hitting one. Look at Dynastar cham HM series.

I hadn't heard of the "HM"'s, I'll take a look. I looked at the regular Chams in 107 underfoot and eliminated them on weight, but a lighter version would be interesting I guess. Big shovels, early rise, and flat tails all seem like good tree attributes.

That book (Physics of Skiing) was published in 2002 so I would think not much is mentioned about rocker. Might it mention "reverse camber"?

Parobolic skis in general were really still in their infancy in 2002. If you look at what was considered "revolutionary" from that perspective in 2000, 2005, 2010, and 2014, the changes have come remarkably fast.

 

[MadMadWorld]

Parabolic....that's a word I haven't heard in awhile

 

[Scruffy]

You're referring to skidding. Maybe I'm wrong, but conceptually, it seems to me that the relationship with the geometric math involved in turn radius is broken when we talk about skidding rather than carving.

Yes you are wrong. That is why I stated my response "even with skidding .... " Learn something about the physics of self-steering with respect to the physics of skiing - even while skidding .

I hadn't heard of the "HM"'s, I'll take a look. I looked at the regular Chams in 107 underfoot and eliminated them on weight, but a lighter version would be interesting I guess. Big shovels, early rise, and flat tails all seem like good tree attributes.



Parobolic skis in general were really still in their infancy in 2002. If you look at what was considered "revolutionary" from that perspective in 2000, 2005, 2010, and 2014, the changes have come remarkably fast.

No, you're off by a decade! Elan SCX came out in 1993, that was about the only "Parabolic ski" made. Very soon after those skis, ski manufacturers realized that having a tip and tail the same dimensions was not a good thing. Ski tails started getting narrower and narrower, relative to tip width even since.

 

[Abubob]

Be careful with the term "rocker", not all skis with rocker are clown shoes. Rocker can mean any and everything to ski manufacture and they use it. Most skis with rocker still have single camber.

Full rocker ski are just that. Cannonball showed me a pair of Volkl skis with full camber. (what models were those Cannonball?) I was amazed that the rise started only a few inches from the toe. The Legends I just picked up show a rise maybe five or six inches from the tip. I just see very little use for a full rocker ski in the east.

I tested K2 Rictors a few years back and found the "early rise" rocker on those skis really did well on groomed snow. I got no use in trees as I was at Okemo but they seemed to handle moguls really nicely. I tried short as well as longer carved turns and they were very responsive. Leads me to the belief that an early rise is the way to go in the trees - at least that I get to ski (by the time I get to most places its pretty well tracked).

By contrast the Dynastar Cham 87s I tried, which have more of an early rise I think than the K2's were awfully floppy on groomed snow and had no hold on uneven surfaces. But they skied pretty well in the trees although they weren't very responsive ... and as long as I didn't have to back up I was okay.

 

[Scruffy]

You're referring to skidding. Maybe I'm wrong, but conceptually, it seems to me that the relationship with the geometric math involved in turn radius is broken when we talk about skidding rather than carving.

To be clear here, we are talking about skidded turns here, which is the turns you'd use mostly in trees, not simply skidding sideways.

 

[Scruffy]

Full rocker ski are just that. Cannonball showed me a pair of Volkl skis with full camber. (what models were those Cannonball?) I was amazed that the rise started only a few inches from the toe. The Legends I just picked up show a rise maybe five or six inches from the tip. I just see very little use for a full rocker ski in the east.

.

Again, "rocker" has become an industry buzzword, so buyer beware.

 

[BenedictGomez]

Yes you are wrong. That is why I stated my response "even with skidding .... " Learn something about the physics of self-steering with respect to the physics of skiing - even while skidding .

Yeah, that doesn't help me. I'm thinking about the turn radius mathematically, and it refers to arc. Once we break that relationship of arc, as we 100% factually are with skidding, I don't understand why radius as a metric, matters.

So you can say......

The shorter the radius the ski is designed to turn in, the quicker the turn even in a skidded turn, via self steering.

And maybe it winds up being completely true, but I don't see how it can be specifically due to the math involved in calculating radius. FWIW, I also have no idea what "self-steering" means either. Maybe I'll make it a point to demo something with a 14 radius immediately followed by a 24 radius and try them in the trees to see.

 

[Abubob]

I can't believe this is still available online. An article by Shane McConkey on the Volant Spatula.

http://www.evo.com/what-is-so-speci...ula-powder-ski-how-do-i-ski-the-spatulas.aspx

Now as I sit here and write this its October 2002 and Volant is making the first batch of the greatest powder skis ever.