Ski "roll" angle: More not necessarily better?

[gregy]

AM has a T2 set up on a stand at nationals. They had it clamped a few inches in front of the fin and a screw with a compression force gauge. At 80lbs it twisted it was around 15 degress of twist. Very noticeable. I'll be out Thursday again see if I can get a picture of it. I talked to his son Mike he was talking alot about the ski coming of the turn.

[gator1]

@SkiJay‌ I'm sure he would. Unfortunately a list of circumstances (bindings, boots, tendons) prevent me buying a ski from him. Not fair to tie him up to satisfy my curiosity. He's got a business to run.

[SkiJay]

That's considerate @gator1, especially during Nationals. But Andy also understands coverage on BOS, and I was assuming you'd share what you learned with the rest of us. If you let him know that you want to shed light on the concepts of roll angle and ski torsion with your fellow ballers, he'd very likely value the time as an investment. He has a new story and he'll be working hard to spread the word.

[gator1]

Well, I'm sitting in airports next couple of days so I'll give it a try. You are assuming correctly, of course.

[gator1]

@SkiJay‌ @Than_Bogan‌ I sent the following email off to Mike Mapple, and got an immediate reply.

 

Me: "blah blah.....in the middle of the debate you announced your new ski, which seemed to be designed to limit the ability of the skier to roll the whole ski up on too much of an edge, by flattening out the nose as the tail digs in. In effect providing lift to the front of the ski and keeping it from auguring in as the back of the ski IS auguring in providing angle.... So that's my question. Is the design intent what it seems to be?"

 

Mike replied: "Yes. The intent for the design of the Torque is to improve the pull and angle from the apex of the turn to off the second wake. Was it designed to make a better turn? No. BUT, if we approach the turn in better shape, earlier and more consistently, we will have better turns.

 

All skis are very torsionally stiff due to their shape, so cross fibers or 0-90 does not do hardly anything in our opinion. We have flex in a ski to enable the ski to roll on edge and rotate into a turn (imagine how hard it would be to have a ski turn that was very stiff). The ski at the end of the turn is then rolled against the boat and allows the skier to create a load. However if the whole ski is rolled over how we want it creates an immense pressure through the front to the ski, which then forces the ski deeper and ultimately trying to go behind us.....thus something must give on the skier to compensate.....hips drop back to gather the ski, or arms separate to create time to bring the ski back forward. Many skiers have been working with counter rotation to get everything moving forward before in anticipation of the load that is about to be created. A good concept, but extra movements that can create inconsistency for one day to the next or site to site. The Torque series does allow for the pressure created at the front of the ski to release as the tip rotates flatter at a different rate than the rest of the ski, thus keeping everything moving forward"

 

Me: "BTW I was pretty proud of myself that I saw the difference in the way the ski rides just by watching from shore while Jeff rode it"

 

Mike: "Keen eye!"

 

 

So there you go......now I really want one. Pretty amazing company that they reply to some unknown schmuck in about 1 hour.

 

 

 

 

[Than_Bogan]

THE @gator1 is not some unknown shmuck!

 

Nevertheless, that is pretty awesome and makes complete sense. I (and I'd venture to say also @gator1) tend to be extremely skeptical about marketing fluff posing as engineering, so perhaps it means something when I find myself nodding and understanding Mike's actual explanation.

 

It does make me want to try one! Crap, I freakin' love my ski. Will these guys stop making newer awesomer stuff dammit!?

[SkiJay]

Thank you @gator1‌ and thank you Mike. This is finally starting to make more sense. The claims of "more angle," "more leverage," and "keep everything moving forward," were getting stuck in my marketing-hype filters because they are just worn out claims that we hear every year. I need to understand why and how. For whatever reason, I think Mike's description clicked. If indeed I am understanding correctly, the Torque concept is largely about bite-proofing the tip, or at least mitigating tip-bite. Letting the tip twist like this makes tip-engagement more linear or progressive instead of exponential. Have I got this right?

[gator1]

@SkiJay‌ I'm like our old buddy Rumsfield: I know what I know, but I don't know what I don't know. So file this under stuff I don't know, but am interpolating from @mike_mapple‌ answer:

 

I think the Torque design intent includes the tip-bite, but goes beyond that point in the pass and helps in modulating the ski roll in the work zone as well. WAY back at the start of this thread when THE @Than_Bogan‌ sucked me into this my theory was that too much roll presents too little surface area of the ski to provide lift, so it sinks into the water and just makes more drag. Put a knife up on edge perpendicular to the water and there is no lift; you get massive load from the boat but you head towards the bottom of the lake. So, you have to roll the knife off edge to get some lift out of it and now you are sliding towards the boat.

 

Now take the same knife, twist the front of it so it gives some lift while the rear of it is perpendicular to the water. The front keeps you from diving into the water, while the rear keeps the ski moving tangent to the load from the rope. I think that is the Torque.

 

I left this up before I hit "post", had a killer sunset session out at the lake, followed by a nice arrogant bastard ale (best beer in the world except for double bastard ale). So, now, I'm convinced you can file this under "stuff I am pretty sure I know".

[mwetskier]

no one gets their ski even close to perpendicular to the waters surface. no one. and any time the rope has load on it you are sliding down course, though i dont think you can actually slide toward the boat because its also travelling down course. it provides the force that makes you slide down course so your not going to close that gap by releasing the pulling edge of the ski.

 

my sense is the torque design works the way it does primarily because it's wider under the bindings and has a much narrower tip than the mapple 6.0. the narrow tip makes it easy to engage so it facilitates a sharper turn. but when its over turned into an angle the skier can not maintain the forward section is the first to twist under the load. this releases the edge holding ability of the front half and the ski gives angle back to the boat in a way thats much more controllable than just being stood up out of your lean by the pull. in a way it feels like it sort of automatically ' self corrects ' if you try to over turn the ski on to an impossible path.

 

b t w thats the t -2 i'm talking about.

[MrJones]

I just scanned this thread, but I thought this might be interesting to some of you. I was talking to Jeff about bindings at the CR Big Dawg. He said he like rubber b/c it was more forgiving and did not excessively roll the ski over if he gave it too much input. Of course I knew nothing about the "T" series of skis at the time, but I'm sure he was on one or at least aware of the project. I am far from an engineer, but seems related.

[MrJones]

Of course, Ben Favret is one of the most successful Big Dawg skiers ever and has metal brackets running up the sides of his hard shell to stiffen it more. It's the Indian, not the arrow.

[gator1]

Well, so much for @Horton‌ 's discussion of Jeff's Wileys "....They are tight and stiff. I promise the roll angle of his ski matches the roll angle of his foot."

[Horton]

@gator1‌ have you had your feet in Jeff's bindings? I have.

[mike_mapple]

@mwetskier the t2 and 6.0 are like comparing apples and oranges. The tip is not designed to be narrower, but it is wider under your feet. If you wanted to compare a torque series with a 6 series it would be a t2 and 6.1.

 

Feel free to shoot me an email if you have any questions regarding the ski though!

[Horton]

@gator1‌

Look there is no question that lateral binding stiffness makes a difference. I have tested multiple bindings of the same design but of slightly different stiffness. The biggest difference that I noticed was at the edge change. Softer bindings offer some dampening and smooth out the transition. As bindings get too soft some connection is lost and I can see where the roll angle would be less.

 

If I wanted less ski roll I do not see why I would not also want less lean. Why would I want to lean on the rope harder but have the ski flatter? I know personally I need less load so I need to lean away less. A few degrees of roll angle is irrelevant if I have more load than I can manage.

 

Skiers who carry more speed out of the ball will have less lean & load for the same speed at the centerline and the so less roll. In this case the roll angle is the result of everything else.

 

Frankly I do not follow the point of this whole thread. If there is some take away that I am missing please someone spell it out in a few short sentences. If there is a nugget that can help me understand skiing better or give me a ball please gimme the Readers Digest version.

 

[MrJones]

I was unaware that threads had to have a point. If this is the case it is going to severely cut back on the volume on the site. ;)

[Horton]

Cute @MrJones‌

[eleeski]

Roll over too far and your butt hits the water. Don't roll over enough and you do a sideslide.

 

So many factors influence a skier's path that focusing on lean angle is silly. The top skiers get more edge in the water and balance better so they go the right direction faster. Do what feels best for you and your ski.

 

Short enough?

 

Eric

[Than_Bogan]

@Horton You are, in fact, missing the point. And it's a significant part of the explanation of why the Torque makes sense. Here's my best attempt to boil it down to a sequence of key points:

 

You must load the line to generate the force that puts you on the path you need.

 

The roll angle can be adjusted relative to the load on the line. (I.e. load and roll angle are not the same thing.)

 

Neither more nor less roll angle is strictly better. There are advantages to less (such as less resistance to acceleration and more fin the water) and there are advantages to more (such as more water to push against to generate force). Since neither end is the best, there is some ideal roll angle in between.

 

The effect of roll angle is (probably) different at the front and back of the ski.

 

A ski that could flex torsionally potentially could mix the ideal roll angle of the back of the ski with the ideal roll angle of the front of the ski.

[Horton]

Mmmmm yea I have heard a lot of positive reports about the new Mapple. Torsional flex is something ski companies have been experimenting and struggling with for 5 or 10 years. Mapple may have cracked the code in terms of ski design.

 

I didn't really think this thread was about ski design. Well that's not true. I really didn't know what the heck this thread was about

[gator1]

I don't know what the thread is about.

 

I do know I was/am trying to decide if I should be trying for maximum roll angle in the work zone.

[Horton]

Quote from Yoda

Pick up the line with speed, load hard into 1st whitewash, move forward over ski before 1st wake, THEN your ski can be flat

[JAS]

@DanE‌ I agree with you, similar to "course" and "heading". Often forgotten is that the ski accelerates the skier. COM position of skier determines whether his body translate forward at same speed of ski, or pinwheels with ski getting shot forward . Since acceleration is dynamic, so must COM position. The greater the acceleration, the farther COM must be forward to maintain optimal stack. Quality of stack = efficiency of energy transfer. I have no idea how torsional rigidity might play into this other than allowing skier to more finely balance lean with optimized COM/Stack.

[Horton]

My thinking is load and intensity and be controlled. Only go as hard as you can control. Roll vs load is not something a skier can adjust between the ball and wakes.

[Than_Bogan]

@Horton Quite frankly, you're taking a very strange attitude about this thread.

 

The thread is academic, in the true sense of the word: It aims to learn something about the world.

 

Having learned something, one can apply it to whatever one wishes: technique, ski design, watercoolor debates, or anything else.

 

There's still MUCH more to learn about roll angle, but some baby steps happened in this thread.

[Horton]

@Than_Bogan‌ meh.

[jimbrake]

Anytime you are attempting to turn a sliding board that relies on edge angle, rocker (including camber forced into rocker), and flex, you want a pretty high degree of edge angle to facilitate an efficient turn, but then you want to be able to release or bleed off that energy stored in the edged/flexed board. This release of energy is a little more problematic on a sliding board that relies on burying a large portion of that board into the medium like a water ski or surfboard or skis/boards on soft snow. Snow skiing race skis rely on high torsional rigidity to hold on a hard surface, in soft snow and water, you need something to grip less and release easier, so that appears to be the idea here. I have no idea how well it works. Would love to try it, though. I definitely suffer from too much edge, bite, pressure, and release on my ski, but I know that is mostly my issue and not my ski's. Would I like to have a ski that helps me with my problems? Yes.

 

[jimbrake]

I meant to add this photo of Nate to show two skiers with super high edge angle that both are at the top of their respective games. Ted's edge release is very different from Nate's.

 

[SkiJay]

To me this whole soft torsional concept may increase forgiveness but at what cost. When I was racing sailplanes, there was a similar conceptual debate. It was stiff carbon wings vs. softer glass wings. The softer glass was a nicer ride and more user friendly, but stiff won more races. In race cars, a flexible chassis is more forgiving and confidence inspiring, but stiff chassis respond better to chassis adjustments and win more races. Even tires exhibit the same relationship; the flexible sidewalls of a bias ply race tire are more forgiving, but the stiff sidewalls of radials are faster.

 

I could go on, but my point is that soft torsion strikes me as being a similar tradeoff. It seems like it should be more forgiving but not as potent in qualified hands. Perhaps it's exactly what most of us need. But will it set world records?

[thager]

Seems to me that maximum angle I can hold on to to get cross course beats unsustainable angle every time.

[SkiJay]

True @thager‌, but isn't unsustainable angle a fail? Whether it's the skier or the ski's setup, a good skier on a tuned setup doesn't grab unsustainable angle with any kind of ski.

[thager]

You assume this ski is only for good skiers. Also. no one, especially me ever skis six perfect turns.

[SkiJay]

You've misunderstood me @thager‌. In my post I specifically said it may be just what most of us need. My question is what is the tradeoff for all this forgiveness. Usually, and maybe always, forgiveness comes at a cost of reduced ultimate performance. Maybe this T series is a step forward in ultimate performance, but usually that comes at the cost of a narrower operating envelope.

 

For the record, I'm not saying this is the case with the T which may well have unlocked a key advancement. I hope it has. Time will tell.

[thager]

My guess is the rear of the ski is standard with the tortion flex occurring mostly in front of the front foot eliminating the tip rise and subsequent correction needed of biting too much angle. The tip stays down reducing time lost getting the tip back down to reestablish cross course angle. Just a guess and I am dead tired!,

[ForrestGump]

Screw it. I'm going out to turn, lean and repeat while you guys play with your slide rules. ;)

[thager]

@ShaneH Good morning to you too!!! What's a slide rule?

[Marco]

It's that thing on your desk sitting right next to your abbucus.

[cragginshred]

I just wanna see video of Ski jay, and ShaneH among a few others skiing! I have video of JimBrake and his son -they rock! Everything else is theory

[SkiJay]

Here's yesterday's opener on someone else's ski @cragginshred‌. Your turn ;)

https://www.youtube.com/watch?v=ilzcL4LPATQ

[bogboy]

@SkiJay‌ smoooth.