Nordic Rocker

[Johnny]

Asnes Ingstad BC skis, showing traditional camber (top) and Nordic Rocker once weighted (bottom)

Source: Johnny / LilCliffy
A cross-country ski with rocker tips? Really?

When holding new Nordic Rocker skis together, you can see and feel a normal XC ski with traditional camber. Skis touch near the tip where they should. No real signs of rocker yet. But step on the skis or press them against each other and the Nordic Magic kicks in. With some pressure, the tips open up and reveal a rocker. The tips open like a true rockered BC ski, hidden until you apply pressure on the ski. How cool is that?

The Nordic Rocker technology by Fischer was first announced in 2011. It was first available on their S-Bound and Spider series. "Nordic Rocker Camber: No, the tips and tails don’t have the obvious splay of alpine and tele skis with rocker. But the tip does rise over traditional skis when weighted. This aids in climbing, as the tip will climb up out of the snow, and in turning in soft snow."

Here is an excerpt from a technical paper: (Google-translated)

"Skis with a Nordic Rocker design are unmatched in deep and fresh snow. They are easy to manage due to increased ski tips; they return faster and effortlessly due to the redistribution of pressure. Nordic Rocker design is characterized by two digits. For example, in a 10/15 design, the digit 10 indicates how many millimeters the toe is raised when the skis are weighted. The number 15 indicates the number of centimeters on which the area of ​​greatest pressure from the toe to the heel during the load is displaced. Thus, at the moment of compression of the ski, the tip is unloaded and the ski is not buried in the snow, providing good flotation."

At the present time, only a few manufacturers are making skis with Nordic Rocker, mostly Fischer, Rossignol and Asnes.

Nordic rocker or just rocker?

"Nordic rocker" is not the same thing as rocker. A rockered profile is the opposite of a cambered profile. And although some Nordic skis do have a truly rockered tip- skis with "Nordic rocker" have a traditional full-length cambered profile (i.e. the unweighted contact points are at the tip and tail).

A fully rockered ski would offer zero true Nordic "kick" and would be extremely inefficient as a XC ski.

A Nordic ski with a truly rockered tip gives up some kick and glide efficiency in exchange for "early tip rise" (i.e. causes the tip to rise towards the surface of the snow). Early tip rise facilitates a number of things including trail-breaking in deep, soft snow; downhill turn initiation; and uphill climbing.

Traditional Nordic skis have a full-length camber for a number of good reasons- not the least of which is to maximize the glide length/surface during the glide phase of classic kick & glide XC skiing.

A ski with "Nordic rocker" appears to have a traditional Nordic camber profile- with no tip rocker. However- when a ski with Nordic rocker is fully weighted (i.e. the camber is fully compressed), the most forward contact point of the ski moves back and the tips open up (i.e. appear "rockered").

Different contact points on different Nordic Rocker skis

I have been examing the tips- both weighted and unweighted-of a number of my BC Nordic skis:

1) 2006-2009 Madshus Eon: no Nordic rocker
2) 2001-2013 Karhu XCD 10th Mtn/Madshus Epoch: no Nordic rocker
3) 2001-2013 Karhu XCD Guide/Madshus Annum: no Nordic rocker
4) 2015 Asnes Combat Nato/Ingstad: no Nordic rocker
5) 2015 Fischer E-99: considerable Nordic rocker
6) 2015 Fischer E-109: considerable Nordic rocker

Fischer claims that the current S-Bounds all have Nordic rocker. I have not tested any of them in several years. Would be great to hear from other skiers with S-Bounds and get their observations regarding Nordic rocker.

I was actually surprised by how much my E-99/E-109 tips open up once they are weighted. (BTW both of these skis open up at least twice as much as the 10cm shown in Fischer's diagram below).

Both the E-99 and the E-109 are cambered like a classic XC ski- but the opening of the tips is very different from any BC-XC ski I have ever owned. I will be skiing on them this winter and will be able to compare them to my other skis that do not have "Nordic rocker".

When kick and gliding, making your way through deep snow, the Nordic Rocker will sure help stability. With light pressure on the front ski, the rocker will keep your tips from sinking, they will tend to stay naturally on top of the snow while providing enough support for effective and straight striding. The same applies when climbing and traversing, making the ascent more stable and safer due to the fact that the amount of the snow over the ski should be much lower. Rocker tips always keep you from sinking on the uphill. And on the descent, turn initiation is much easier than any other cambered ski.

The idea of adding either true rocker or, Nordic rocker to a backcountry Nordic ski- intended for deep, soft snow- opens up some very exciting possibilities. For example, ski manufacturers have been building BC Nordic skis with significant sidecut for some time- to offer a tighter turning radius. While this is awesome for turning on a dense base, it can make for a "squirrely" XC glide, and it can also significantly reduce surface area/flotation on narrow and mid-width skis. What about taking a mid-width Nordic ski, add tip rocker (or Nordic rocker), but reduce the sidecut. A ski with this design would have a longer turning radius- than a similar ski with more sidecut- but it would track straighter, offer more flotation, still offer decent turn initiation, and should still be manoeuvrable on soft snow.

Just like computers and synthesizers in the 70’s, it’s still too early to see how people will react, and what use they will make of such a new technology. But this is probably the most promising (and exciting!) ski technology on the market right now. This is truly something new, which could change our perspective on XCd and xcD skis for the years to come.

[Baaahb]

Nice post, though it did not generate a lot of immediate traffic.

I have been wondering why it is hard to find a narrow ski that is easier to turn. It seems that:

a: a rockered tip makes it easier to turn

b. a narrow ski is easier to edge with light boots than a wider ski, and thus easier to turn

and

c. a softer ski is easier to turn.

However, in most US product lines of fishscale skis, as the skis are narrower, they are also stiffer. F'r'instance - though my personal knowledge is a bit dated at this point -- the Fischer outtabounds is much stiffer than the fischer boundless.

Asnes seems to have dug deeper into this with narrow skis that both have generous sidecut and also are softer, such as the Nansen and Gamme 54.

[bgregoire]

Nice post, though it did not generate a lot of immediate traffic.

I have been wondering why it is hard to find a narrow ski that is easier to turn. It seems that:

a: a rockered tip makes it easier to turn

b. a narrow ski is easier to edge with light boots than a wider ski, and thus easier to turn

and

c. a softer ski is easier to turn.

However, in most US product lines of fishscale skis, as the skis are narrower, they are also stiffer. F'r'instance - though my personal knowledge is a bit dated at this point -- the Fischer outtabounds is much stiffer than the fischer boundless.

Asnes seems to have dug deeper into this with narrow skis that both have generous sidecut and also are softer, such as the Nansen and Gamme 54.

Hiii Bob,

Yup real easy turning skinnies are hard to come by today. There used to by a time when single camberered nordic skis where quite popular, those were the days of Norpine:

https://www.telemarktalk.com/viewtopic.php?f=1&t=2211

FWIT, I'd bet the new Fischer xtralite E99 is easier to turn than the Asnes Gamme 54. Some versions of the Madshus Glittertind are also apparently quite soft.

Totally agree with your points a and c. Not so sure about b when comparing a ski like the E99 to the wider, high sidecut turny crosscountry skis like the Epoch/Annum/S98/etc.

[Baaahb]

A wider ski puts more torque on the binding when edging on firmer snow. With a firm boot binding interface that's not significant, but with a lighter interface (BC or 3-pins) it translates into increased boot/binding wiggle. Of course other factors come into play as well, such as sidecut and softness of the ski..but all other things being equal, with a soft boot/binding a narrow ski should be easier to put on edge than a wide ski on firm snow.

[fisheater]

A wider ski puts more torque on the binding when edging on firmer snow. With a firm boot binding interface that's not significant, but with a lighter interface (BC or 3-pins) it translates into increased boot/binding wiggle. Of course other factors come into play as well, such as sidecut and softness of the ski..but all other things being equal, with a soft boot/binding a narrow ski should be easier to put on edge than a wide ski on firm snow.

Baaahb,
First nice to see you over here. I enjoy reading your posts elsewhere. I have an S-112 that has become a loner ski. I have replaced it with a much more narrow ski, however I do not have a loss of performance over the S-112 in powder up to 12" deep. I have not had powder deeper than 12" to test it. The ski is an Asnes Falketind 62.
The FT 62 is a single cambered Nordic ski with rockered tips and tails. It is flat to the trail on hard packed trails, so it doesn't perform well in that regard. I still prefer it greatly to the S-112 in that situation. The ski comes to life in as little as 4" of soft snow. It is torsionally rigid enough to ski the groomed, however it is a touring ski, it does not handle difficult conditions well. Again, no comparison to the S-112, it is far superior. Going downhill in up to 12" of powder off piste the FT 62 is a really fun ski. The S-112 is also fun to ski in those conditions.
So if you are looking for a ski to replace some old Fischers, I would recommend you look at what Asnes has to offer. Many models are available from Neptune Mountaineering out of Boulder. There are reviews of many of these skis in the review section. There is a ski called the Rabb 68 that may hit the sweet spot better than the FT 62 depending on what you are looking for. I went skinny when I ordered mine, I wanted something different from the S-112. The FT 62 does so much more, so much better I have not skied the S-112 in quite some time. The Rabb 68 still may be a better option, I'm not sure, but it is getting good reviews here. If you want to mount NNN-BC the FT 62 might be a better choice. However, Johnny mounted a Tindan 86 NNN-BC (86 mm underfoot)
If you are looking, I hope I helped. Regardless, nice to see you posting over here.
Bob

[dhdaines]

I have been alternating between non-rockered and rockered E99s this winter and at this point I can really tell the diffference.

The rockered ones are 195cm, NNN-BC, which I'm skiing with Alpina Wyoming boots (much softer than Alaskas). The non-rockered ones are 190cm and have Voile 75mm cable bindings, which I'm skiing with Karhu Descent boots. In theory they should be way better for turning, but they really, really aren't. I took them down the easy groomed runs on the "north" (actually east) slope of Mont-Tremblant in new snow and even that was honestly a pretty miserable experience. I haven't tried the new rockered ones on anything like that, but I continue to be impressed with how well they turn both in trails and when wandering off to the side, as you do. They don't like to turn when there's a hard crust but they are still pretty narrow after all...

EDIT: I have been taking my rockered E99s to Mont Alta lately and they really are a blast! The long skin track is just gentle enough to climb with wax, and they are great fun on the intermediate runs and in the trees. It may be just the lighter weight but I can almost sort of jump-turn them which I can't with the old ones.

What the non-rockered E99s *are* good for is breaking trail. As pointed out elsewhere, the new ones bob up and down in deep snow, which is tiring and annoying and makes me wonder if I should just be wearing snowshoes instead. The old heavy ones just go straight forward, crushing everything in their path.

EDIT AGAIN: I switched out the Voilé bindings for NNN-BC on the non-rockered E99s giving me a fairer comparison. The reluctance to turn is still there, but what really stands out is that while they aren't good downhill skis, they are really good *trail* skis. The trail initiates the turn for you but more importantly it's useful to be able to swerve off to the to slow down, and the rockered E99s kind of suck at this as they tend to stall out when you leave the trail, especially if there is a crust under the snow somewhere, whereas the old ones are a lot more stable when moving between hard-packed and deep snow.

I am guessing at this point that someone will recommend Gamme 54s which should give me the best of both worlds

[lilcliffy]

@dhdaines
Thank you for an excellent report and comparison between the rockered and non-rockered E99!
Very helpful indeed.
Yes- the notion that tip rocker somehow improves trail breaking on a ski as narrow as the E99 is just plain BS- IME.
The difference in turn-initiation and downhill planing is quite something though!!!