Is tip-rocker always a good thing?

[lilcliffy]

I am wondering whether others have thought about tip-rocker with a critical mind.

Rocker is an amazing thing. I am not suggesting it isn’t. But, is it an asset to every ski, in every context?

I have always been blown away with the simply wonderful performance of skis with tip rocker when downhill skiing- especially on deep, soft, fresh snow. Even on hardpack, a rockered tip reduces the effective edge and facilitates turn initiation (my boot feels like it is mounted further forward than it actually is), and as a result it also reduces the turn radius of the ski. A rockered tip also helps prevent tip-dive when skiing on deep snow, with a forward mounting point.

When it comes to early tip rise though, I have realized that a ski must be floating high enough in the deep snow in order for the rockered tip to be effective. In a down-hill context, this is rarely an issue, because you are travelling at enough speed, that even a modest-width ski is going to rise and plane in deep snow if it has a fully-rockered tip.

But- what about breaking trail through truly deep soft snow in a backcountry cross-country context? What I am discovering is that unless a ski has enough surface area to float near the surface of the snow- a rockered tip can actually be a liability when XC skiing through truly deep soft snow. When XC breaking trail through the deep pow, one is rarely travelling fast enough for the ski plane- therefore, a ski that does not have enough surface area to float- sinks. And, if the ski sinks, and has a rockered tip that wants to rise, the ski becomes completely unstable, and is often stuck in strange, unstable and completely inefficient angles.

Some examples with the kits I am currently skiing on in my local hilly backcountry (bear in my mind that I weigh 185lbs without any gear):

1) My 145cm Hoks float very effectively, and as such the rockered tips do rise and help keep the entire ski floating on top of the snow as they XC glide.

2) My 195cm Annums float quite effectively, but as the tip is low-profile, and not rockered, the tip usually stays beneath the snow if I am XC breaking trail through very deep, soft snow.

3) My 205cm Eons do not float on very deep soft snow. This ski has a soft flex overall- but, the tip and tail are very soft. When XC trail-breaking in deep soft snow, the waist of the Eon sinks deep into the snow, with the tip and tail floating higher up in the snow- YUCK- HATE IT.

4) My 205cm E-109s do not float on very deep soft snow. This ski has considerable Nordic rocker in the tip, but has a stiffer, flat tail. In very deep soft snow, the open tips want to rise, leaving the rest of the ski buried in the snow. It creates a sensation as if you are always on a slight incline, trying to climb your way up and out on to the top of the snow. I keep feeling- “if I could only glide fast enough, these skis would plane and rise up to the top”. Of course I never XC ski fast enough in very deep snow for the E-109 to plane- you are left feeling like you are breaking trail with the waist of the ski. YUCK.

5) My 210cm E-99s actually feel more stable than the E-109 in very deep soft snow. I think it is a product of the narrower tip not floating and rising as much. But- on the flip side, the extra camber and stiffness underfoot is more difficult to control than the softer flex of the E-109 in very deep soft snow.

6) My 210cm Combat Natos do not float on very deep soft snow either. They have no tip rocker of any kind. This ski- though having a softer tip and tail than its cambered midsection- has an overall flex that offers stability throughout its length. Although this ski still sinks in very deep soft snow, it is very stable, along its entire length- therefore, it breaks trail very effectively. (As an aside- its kick-ass broad, raised tip also helps- ALOT).

The physics of this are obviously both complicated and complex. But- ski manufactures seem to be adding tip rocker to most every ski these days- and I wonder whether it is always an asset to every ski. What do you think?

[MikeK]

Not sure I have a very in-depth experience on rocker, but I seem to like it, at least the way Fischer does it.

I still like skis that don't have it. The Eon (not really rockered per se), Epoch and Annum are great all around skis.

Would I buy XCD skis with rocker? Sure. I actually think my XC/XCD quiver is quite good now and don't plan on adding anymore skis, but the Falketind skis (with both tip and tail rocker) would be high on my list. Not sure how I'd get them in the US (yes, I already looked into it)? The Objective (and now classic Vector) are obvious contenders, both with tip rocker. Pretty sure the KOM is off my personal radar. Too short, too wide, and too stiff (appearing)... and perhaps not enough rocker, although it appear to have more of a Nordic Rocker like Fischers, so I probably wouldn't mind it.

For a frontside resort ski, I'm not sure it makes a lot of sense. Perhaps it has some merits in cruddy, chopped up crap and low, mushy bumps? As far as an effectively shorter ski, for hardpack, where float is not an issue, I'd just ski a shorter size. It makes a lot of sense for All Mountain skis where you want a balance between powder and piste performance. Ideally though, for the most performance, you'd have a pair of short, narrow frontside carvers and a pair of wider, rockered powder skis.

[Woodserson]

On my long skis like my 99s for distance straight travel, no rocker.

For carving sweet trenches and leaving railroad tracks, no rocker.

For everything else, rocker. Woods, mank, pow, crud and gnar, dust on crust, snorkel-worthy deepness, yes, rocker.

My opinion only fwiw.

Additionally, I think it has to be well designed rocker. I've seen different skis of the same type with wildly different kinds of rocker, tough to describe. I bet some companies do it better than others. No expertise, just a hunch. Voile is like magic.

[lilcliffy]

On my long skis like my 99s for distance straight travel, no rocker.

For carving sweet trenches and leaving railroad tracks, no rocker.

For everything else, rocker. Woods, mank, pow, crud and gnar, dust on crust, snorkel-worthy deepness, yes, rocker.

This all resonates with me.

Additionally, I think it has to be well designed rocker. I've seen different skis of the same type with wildly different kinds of rocker, tough to describe. I bet some companies do it better than others. No expertise, just a hunch.

This is true isn't it? So much of ski design and innovation appears to be more like a shot in the dark, or alchemy, rather than engineering...(not to suggest that there isn't engineering involved as well). The ski manufacturers at least seem to be learning from their all-out experimentation with "if a little is good- alot must be better!" I haven't seen or heard of too many new skis with the full-on banana-shaped full-rockered flex profile.

Voile is like magic.

I believe you- and you are not the first person to say this...Perhaps replacing my old Guides with the Objective or even the Vector should be obvious?
.......

In all fairness, the effectiveness of tip rocker on the BC-XCD skis listed above, entirely depends on intended use and snow conditions.

For example, as long as one avoids truly, deep soft snow (i.e. use a fat ski in the pow), the tip rocker on the E-109 and the E-99 is not a problem. And in a XCD context, the Nordic Rocker does make a big difference in turn initiation. I find the E-109 to offer better turn initiation than the Combat Nato- despite being more cambered and stiffer underfoot...In fact- the E-99 probably has easier turn initiation than the Combat Nato- and it is much more cambered and stiffer...

If I only had one XCD ski, I think the current Combat Nato without tip rocker offers the widest possible range of backcountry Nordic touring performance- despite the fact that the E-109 is easier to turn.

[lowangle al]

I wouldn't but a new ski w\o tip rocker. I think the advantages outweigh any negatives. They make skiing easier which will make a person a better skier and the better you are the more fun you have.

[MikeK]

I believe you- and you are not the first person to say this...Perhaps replacing my old Guides with the Objective or even the Vector should be obvious?

I think you should stick with your military theme:

http://www.voile.com/voile-vector-bc-skis-white.html

http://www.voile.com/voile-switchback-t ... -grey.html

Kinda cliche, but it works and you have the T4s already.

[lowangle al]

I would get the 3 pin HWS unless you will be mostly skinning.

[MikeK]

I would get the 3 pin HWS unless you will be mostly skinning.

Yeah, but there's no mil-spec HWs

[lowangle al]

I would get the 3 pin HWS unless you will be mostly skinning.

Yeah, but there's no mil-spec HWs

Ya got me there. That military set up would match my new skiing shell. For years I wore green canvas military anorak, last week I found a used white canvas anorak on CL. All I need is some white pants and I would be virtually invisable.

[MikeK]

Well don't forget your pink beanie if you do... we don't want you getting mistaken for a female polar bear