Cage Match Comparison 2017 Head Supershape Rally vs 2017 K2 Super Charger

[markojp]

FWIW, last season i skied either a Titan or a Blizzard WRC on hard snow. Grew to love the WRC and will replace.it with an iSpeed Pro (wc plate, a bit stiffer... Sort of like a hero master vs the hero LT thing) cheater. I work most of the time on an 88, and I have a powder ski that sees about 8 or so days a year at a mountain that averages around 500". I'm on snow 5-6 days a week. Holy thread drift, eh?

 

[markojp]

Returning to the Cage Match, no one has followed up on my comment that there is a big difference in delta between the 0 mm of the K2 and the 4 mm of the Head. This difference is large enough to be an important part (not the most important part, but certainly an important part) of why these ski differently. I.e., when you compare these, you're not comparing just the skis, you're comparing the skis plus the diff. in delta. Given (correct me if I'm wrong) that they are both system skis and will thus typically not be sold flat, that difference is practical rather than potential. Of course, one could say such differences are routine, but I demoed a good sampling of skis from many manufacturers over the past few years, and found the deltas were all 2–4 mm, i.e., within a 2 mm range, so I'm wondering if this represents more of a difference than is typical. Would be interested to hear @bud heishman 's take on this.....

Sure... Depends on the boot, boot set up, bsl, anatomy of the skier, etc... 4mm for a small foot can be a lot.

 

[chemist]

Holy thread drift, eh?

Yeah, I have to take responsibility there — that was mostly my fault.

 

[Philpug]

Returning to the Cage Match, no one has followed up on my comment that there is a big difference in delta between the 0 mm of the K2 and the 4 mm of the Head. This difference is large enough to be an important part (not the most important part, but certainly an important part) of why these ski differently. I.e., when you compare these, you're not comparing just the skis, you're comparing the skis plus the diff. in delta. Given (correct me if I'm wrong) that they are both system skis and will thus typically not be sold flat, that difference is practical rather than potential. Of course, one could say such differences are routine, but I demoed a good sampling of skis from many manufacturers over the past few years, and found the deltas were all 2–4 mm, i.e., within a 2 mm range, so I'm wondering if this represents more of a difference than is typical. Would be interested to hear @bud heishman 's take on this.....

As @markojp said, that delta difference is more prevalent the smaller the boot gets. There are skiers with 265mm shells that were considering the one of the Head systems that I would just make sure there knew they were have the ramp that they would. I think it is great that K2 is making this ski with a 0* ramp, adding to the fact that they are serious about making a ski of this caliber.

Yeah, I have to take responsibility there — that was mostly my fault.

Yeah, but it was a great thrift topic, I am trying fo figure out a way to extract it and make it into it's own thread.

 

[Muleski]

Interesting stuff to consider. I guess there are a lot of factors that come into play for each of us.

I'll avoid binding Delta for now.....

Yes, our son is 30, very strong, very fit, and(knock on wood) has never had lower body injury. He's the type of skier who turns every head on the hill. And he generates a lot of edge angle even on his widest skis. I hope that he's not doing a lot of damage. He's very compact in his skiing stance. He'd built for the sport. He will pick his skis for the day. Most of his days are such that the Enforcer works, I guess. If he were back East, they'd get less use.

I'm 62, 5' 10" and about 200 lbs., the lightest I've been since I was 16. I've been skiing since I could walk. Ski about 80 days a season these days. I prefer to ski the right ski for the surface, too. If it's rock hard, it's a GS Cheater. If it's merely a bit firm, maybe well groomed, it's a toss up. Might ski my 80mm ski. If it's mixed up and soft, probably my 98mm Bonafides {I'm a fan of the ski, unlike many}. A lot of snow, Bodacious. I ski each of these in the longest length made, other than the cheaters
which are 180's. I'm pretty "current" with my skiing, not so much old school.

I don't have {again, knock on wood} any knee pain, no hip pain. However, if I were skiing a 98mm wide ski on real hard snow, I am sure I would. That's not why I choose a narrower ski, but it seems obvious. I don't see many guys my age "sparkin' arcs" on wide skis and real hard snow.

But I do find myself skiing deep snow on my 196cm Bodacious, and sneaking back to the lifts on groomers, and they work. If I tried to get them way up on edge in those conditions for a few hours, it would be tedious, ugly, and likely painful. Not the right tool at all.

I have skied an 84mm Firearrow EDT for long days on end on hard snow. That's a hard snow "weapon". No knee issues for me. It's got to be more than width, I think.

I'm not a medical professional, no engineer, etc. I would think that somebody like Brian might have some thoughts and insight.

In general, I would guess that many folks might have been better served with a narrower ski, depending on location, in recent years. Back to people buying a ski based both on how they would like to ski, and what they would hope to ski on or in rather than reality. I see very average skiers on shortish 98mm Mantra's as their Eastern one ski quiver, and that looks and seems wrong most days. Rarely do they seem like they are being skied as designed though. Big difference between a 98mm ski and something around 80mm.

Not to sound like a jerk, but the more skilled the skier, the more fit, the more likely they can match the right ski to the surface and have one in the closet that works! The

Just my hunches.

Binding Delta.....hmm. I'll stay tuned.

 

[bud heishman]

Returning to the Cage Match, no one has followed up on my comment that there is a big difference in delta between the 0 mm of the K2 and the 4 mm of the Head. This difference is large enough to be an important part (not the most important part, but certainly an important part) of why these ski differently. I.e., when you compare these, you're not comparing just the skis, you're comparing the skis plus the diff. in delta. Given (correct me if I'm wrong) that they are both system skis and will thus typically not be sold flat, that difference is practical rather than potential. Of course, one could say such differences are routine, but I demoed a good sampling of skis from many manufacturers over the past few years, and found the deltas were all 2–4 mm, i.e., within a 2 mm range, so I'm wondering if this represents more of a difference than is typical. Would be interested to hear @bud heishman 's take on this.....

Very good observation and point! 4mm difference in delta is very noticeable on the same ski let alone between two different brands. Any accurate comparisons should use the same binding and same delta. Point in case, I did a test years ago the first year of the Salomon skis. Taking the 2s skis tuned exactly the same and mounting the top of the line binding from each of the top companies on six pair of identically prepared skis and testing on a firm groomed race hill through a race course, the differences were nothing less than amazing. These skis performed totally differently with the only difference being the binding with which they were mounted. Throwing in a 4mm difference in delta would've skewed the results even more profoundly.

 

[chemist]

As @markojp said, that delta difference is more prevalent the smaller the boot gets. There are skiers with 265mm shells that were considering the one of the Head systems that I would just make sure there knew they were have the ramp that they would.

That's true, but even going to a much bigger boot doesn't reduce the effect of delta that much. E.g., the angle with a Lange 27 (316 mm BSL) is only 13% less than that with a Lange 23 (276 mm BSL) (this applies to any delta you might encounter, except of course zero).

 

[chemist]

Very good observation and point! 4mm difference in delta is very noticeable on the same ski let alone between two different brands. Any accurate comparisons should use the same binding and same delta. Point in case, I did a test years ago the first year of the Salomon skis. Taking the 2s skis tuned exactly the same and mounting the top of the line binding from each of the top companies on six pair of identically prepared skis and testing on a firm groomed race hill through a race course, the differences were nothing less than amazing. These skis performed totally differently with the only difference being the binding with which they were mounted. Throwing in a 4mm difference in delta would've skewed the results even more profoundly.

Thanks Bud . For the comparison you describe, could there also have been some difference created by the difference in the effect of the bindings on ski flex? I believe a better-controlled comparison would be one I think you've also done, in which you use the same skis and bindings, where the only difference is that one pair had lifted toes or heels. OTOH, even with the test you describe above, it's probably possible to identify and separate out the effect of delta, since it changes your fore-aft balance.

 

[graham418]

pardon my ignorance, but what are these 'delta', and 'ramp angles' being talked about?

 

[Philpug]

pardon my ignorance, but what are these 'delta', and 'ramp angles' being talked about?

The relationship of the toe height and the heel height. In this care, the toe on the Rally is 4mm lower than the heel and the K2, the toe and the heel are the same height.

NOTE: I would like to double check the ramp of the Head, I have a number greater than the 4mm that has been posted here. I will swing by @bud heishman's shop today to remeasure and confirm.

 

[Tricia]

pardon my ignorance, but what are these 'delta', and 'ramp angles' being talked about?

No worries. There was a time when I scratched my head when I heard these terms.
Hopefully this helps.
The degree of "ramp" between toe and heel on a boot/binding interface.

 

[njdiver85]

As I ski a Lange 23.5 boot, binding delta makes a huge difference. I wish more manufacturers would provide binding delta specs on their systems skis, or independent bindings. Regarding some of the above comments, I just wanted to point out that usually, the Head Rally's are sold with the PRX binding (not the PRD). The PRX binding has a binding delta closer to 8mm, and that is usually the binding on the demo skis. So someone who demos these skis above may really be comparing apples to oranges.

 

[Philpug]

As I ski a Lange 23.5 boot, binding delta makes a huge difference. I wish more manufacturers would provide binding delta specs on their systems skis, or independent bindings. Regarding some of the above comments, I just wanted to point out that usually, the Head Rally's are sold with the PRX binding (not the PRD). The PRX binding has a binding delta closer to 8mm, and that is usually the binding on the demo skis. So someone who demos these skis above may really be comparing apples to oranges.

This is the number I have, I want to confirm it today.

 

[njdiver85]

NOTE: I would like to double check the ramp of the Head, I have a number greater than the 4mm that has been posted here. I will swing by @bud heishman's shop today to remeasure and confirm.

The Head Technical manual lists the PRD's delta at 5.5mm. Will be interesting to see what you come up with. I believe when I had mine measured, it was closer to 4.5mm.

 

[bud heishman]

Just to clarify, "ramp" angle is generally understood by boot fitters as the "internal" angle of the boot board or zeppa, while the "delta" angle is the external angle created by the binding stand height differential or difference in height of the AFD and the heal rest. This angle will vary based on boot sole length.

Ramp angle affects the angle between lower leg and foot, while the delta angle affects lower leg angle in relation to the ski.

 

[njdiver85]

Just to clarify, "ramp" angle is generally understood by boot fitters as the "internal" angle of the boot board or zeppa, while the "delta" angle is the external angle created by the binding stand height differential or difference in height of the AFD and the heal rest. This angle will vary based on boot sole length.

Ramp angle affects the angle between lower leg and foot, while the delta angle affects lower leg angle in relation to the ski.

All true, but also keep in mind that in the Head Binding Technical Manuals, they refer to it as "ramp angle (mm)", even though they are referring to the binding stand height differential.

 

[bud heishman]

You should let Head know about that!

 

[Philpug]

@bud heishman just confirmed with me. the toe height of the PDX binding is 24mm, the heel 32mm. What does that math tell us? 8mm of differential.

 

[njdiver85]

@bud heishman just confirmed with me. the toe height of the PDX binding is 24mm, the heel 32mm. What does that math tell us? 8mm of differential.

Assume you mean PRX!

 

[Philpug]

Assume you mean PRX!

Yeah.