GUT-104: Understanding the Handle Path Part 1

[Horton]

denaliskis.com

http://www.ballofspray.com/images/2016/Denali_Logo_Black.orig.pngBy: Adam Cord & Adam Caldwell
In slalom, the skier maintains a constant connection to the handle. This physical constraint ultimately defines the skier’s path through the slalom course. In other words, the skier can only go where the handle goes. Specific elements within the system dictate how the handle moves, and therefore how the skier moves, through the course. Understanding the relationship between these elements will help build the foundation for more detailed GUT chapters.

Chapter 104 will explain how only three variable elements combine to dictate the handle path. This discussion is broken into two parts. The first part looks at the motion of the handle relative to the boat. The second part looks at the motion of the handle relative to the slalom course.

Part1: Motion of the Handle Relative to the Boat
To get started, let’s investigate the motion of the handle with respect to the boat while ignoring its down-course travel. There are only three variables that define the motion of the handle. They are:

1. Length of the rope
2. Swing height
3. Swing speed

Rope Length
Like a pendulum, the handle swings on a fixed circular path around the pylon. This path is always a semi-circle (assuming no slack) with its curvature defined by the rope length. As the rope gets shorter, the radius of this curvature becomes tighter. Also, since the width of the course is constant, the overall length of the path traced by the handle, called the Arc Length, will increase as the rope gets shorter. This is graphically shown in Figure 1, below.

http://www.ballofspray.com/images/2016/GUT_104_Figure_1.png

Figure 1: Handle Motion at 23m and 10.25m

Swing Height
Figure 1 also illustrates something about swing-height. The swing-height, or how high the handle must travel on the boat for the skier to reach the buoy line, increases as the rope gets shorter. The point when the handle reaches its maximum height is called the “handle apex.” It should be noted that the handle apex is not the same as the ski apex – more on that in a later section of GUT. The greater the swing-height at the handle apex, the wider the handle will be in the course. Since the total width of the course is a fixed distance of 23 meters, a minimum swing-height for each line length is needed to reach the buoy and run the pass successfully.

Swing Speed
Like a pendulum, there is a symbiotic relationship between swing-speed, how fast the rope swings around the pylon, and swing-height. Greater swing-speeds can help the skier carry the handle to a higher point on the boat. Similarly, starting with a high handle apex can improve the skier’s ability to generate speed. The faster and higher the handle reaches its apex, the earlier in the course that apex will be, and the wider in the course the skier can travel during the reach and extension. Figure 2 below highlights the link between swing speed and height.

http://www.ballofspray.com/images/2016/GUT_104_Figure_2.png

Figure 2: Handle Motion Relative to Boat

Part 2: Motion of the Handle Relative to the Slalom Course
Part one established that for a given line length, the motion of the handle relative to the boat is defined by only swing-speed and swing-height. How, then, does the handle’s motion relate to the slalom course?

Imagine that we are observing the system from Part 1 as it moves down the lake, the same way it does when we are skiing. Watching the handle swing back and forth, we are able to trace its zig-zag pattern on the water. Relative to the slalom course, the handle path traced on the water is based ONLY on the swing-speed and swing-height of the handle!

Slow and Low vs. Fast and High
If we think about the absolute minimum swing-speed required to get from one buoy to the next and successfully run the course, the handle path could theoretically become a straight line from buoy to buoy (the shortest distance between two points). In terms of geometry, this path will cross the CL equidistant between the buoys in the down-course direction. Additionally, the handle will not apex until it arrives at the turn buoy. This kind of handle path creates the sensation that most people describe as being “late, fast, and narrow” to the buoy, when in reality the skier swung “slow and low.” The handle path for a minimum theoretical swing-speed and swing-height is shown below in Figure 3: A.

Conversely, a handle path created by a high swing-speed and swing-height is shown below in Figure 3: B. If the skier is able to generate a great deal of speed into the base of the swing, the handle will cross the CL much earlier. In addition, if the skier is able to sustain a high swing-speed as he swings up on the boat, the handle will reach its maximum height on the boat more quickly, and the handle apex will occur well before the next buoy. This is what most people would describe as being “wide and early”, when in reality the skier swung “fast and high.”

http://www.ballofspray.com/images/2016/GUT_104_Figure_3_A.png		http://www.ballofspray.com/images/2016/GUT_104_Figure_3_B.png
Figure 3 A: Slow and Low Handle Path Figure		Figure 3 B: Fast and High Handle Path

 

Summary
For any given line length, the handle’s path is based only on its swing-speed and swing-height on the boat. Because the skier is always connected to the handle, the only way he can improve his path through the course is to change the handle’s path. Increasing the swing-speed of the handle around the pylon, and sustaining that speed into a high and early handle apex, will make the handle path work in our favor and help us to achieve the primary objective of GUT.

Later we will discuss in detail both how to generate a high swing-speed, and how to sustain that speed throughout the arc of the handle path.

[brody]

This was my favourite section so far, can't wait for the how!!

[wolfgang]

This makes perfect sense and helps with the "visualization". I just hope that with so many new swing thoughts from GUT, in the16 or so seconds available, that I can remember remember to keep the curly end of the ski forward.

[Than_Bogan]

I especially like figure 3B, and I'll call everyone's attention to the handle hitting apex before the buoy. If my understanding of GUT is even close (which remains to be determined), I think that fact is one of the most insightful aspects, especially in how -38, -39, and even -41 are even possible.

 

I think most of us have assumed (in my case even after thinking about it a lot) that to succeed at those extremely short line lengths, the apex of everything must fall right at the buoy. But that leads to a cascading failure, because then you finish that turn and the rope is at a very high angle so you have nothing to pull you and your speed craters. Next you have to take a massive load to try to get going again. For most of us, this starts before even turning in for the gate!

 

When the handle apexes before the buoy (or the 0 ball), that means the rope angle is actually falling back as your ski goes out to round it, and by the time you finish that turn the rope angle is something that can pull on you right away! So your speed doesn't drop nearly as much and therefore you don't have to accelerate as much and therefore you don't have to take as much load.

 

I've only barely experienced this on the water, because I had just one day in November to ski after being forehead-smacked with how this geometry is really working. But it makes sooo much more sense, and I can at least now understand -- at a conceptual level -- how -39 is possible. I don't know if I have the athleticism necessary to learn it, but it's a start to have an understanding...

[Greg Banish]

What about dwell time at the apex?

 

Surely if the boat speed is constant and "swing speed" is increased, getting you across the course quicker, then one must "wait" at the apex for a longer amount of time before once again cutting across the course for the next ball. Otherwise, shortening the rope would only put you earlier for each successive ball and one would "finish" the course in less linear travel unless they intentionally waited a bit more at each apex.

 

Perhaps it is in how one manages that "wait time at apex" that gives us trouble? Waiting generally mean decelerating and sinking into the water if exaggerated. I know we want to keep our linear speed up, even as we pass the buoy. So this means that we keep down-course speed high, while essentially stalled at the handle apex. How does one manage the turn-in that must result since it becomes anything but sinusoidal? We don't want a sudden cut, so you must wait longer at the apex, but still be smooth on the beginning of the next cut and accelerate to a higher speed again.

[Razorskier1]

There is no waiting or dwelling. That is a feeling that comes from not enough speed. When you travel the path this way, you carry a lot more speed than before, and while you are earlier, you don't feel like you are waiting for the buoy and slowing excessively. That would only occur if you don't build enough speed in the first place.

[The_MS]

 

[Wish]

Haha... I like that @MS. I'm sure the Adams can explain it much better but I agree with Jim in the sence that there is no perceived waiting. Don't get me wrong, the buoy ends up way out in front of you and you feel crazy early and even wide. To the point your sure the ski is gonna sink or stall or tip engages too soon. But between the speed generated to CL (remember the highest swing speed is off the second wake) and COM forward maintaining that speed, your beating the boat to the ball. There is no slowing (not much.. more like just enough) or sinking or early tip engaging too soon. I know I'm kinda repeating what Jim said but watch any vid of Nate. I think someone on here called it "posting" where you see him "wait" on the ball. He's not waiting nor is he "posting". It's not a thing he does. It's just an outcome of speed to CL and the high swing speed. He's just beating the boat to the ball in a more forward, dare I say, straight at the ball trajectory as his apex has already happened ealier. That's why every pass no matter what the length seems to look the same. Personally I think (aside from his gate) TW is another you presume is "waiting" and "posting" (again, not a thing). Swear if he was 8" or more taller, it would be the Nate and Terry show at every pro event.

[6balls]

It's gotta be the speed that makes the difference. I've always felt I could be too early just like I could be too late. For example I'm over there waiting and the ski slows, tip engages and it's time to come back in but too soon. Alternatively end up riding flatter until get to ball but then not in good turning shape when time to turn.

 

I get the pendulum, the height, the speed. I think I've been skiing too slow. Have always thought the bigger challenge is after the wake not into the wake. If this makes my life easier after the wake I'll be pretty happy.

[Wish]

@MattP what's the part you disagree with?

[Horton]

@wish that is not what posting means. Posting is where you take the handle forward and down, palm down but keep your inside shoulder and chin high. It was almost all the rage a few years ago. Not sure if the idea fall out of favor or is just misunderstood. I think Will does it. Karina did it a lot. Nicole Arthur is another example.

[Wish]

And I started doing it after some things started falling into place. Only noticed I was doing it from a video. When things are going really well it literally just shows up. To me, like the edge change location, it's a result not an intentional action. If Nate is intentionally doing this as a move or putting himself in that position off the highest swing speed point I would be suprised. It may have gotten labeled that do to the stark contrast compared to others but I garentre if you try to "post" without the correct amount of swing speed, your just gonna sink and fall to the inside. It's a result IMHO. So I have to respectfully disagree. I think we have chopped up slalom into all these little parts and peises from still shots to the point we have blurred the lines between what is an actual action and what is just a reaction. We just start labeling stuff and attempting to do them. My 2cents.

[MattP]

@wish I was disagreeing with your idea on what posting is. @horton described it well. I would love to see video!

[Wish]

At longer line then Nate and was not used to COM more forward with ankle flex but I've never done this before. And I've never tried to do this. For me..a reaction. He's doing a much better job maintaining speed by having more COM forwad and a flatter planing ski. He carries the speed to the ball and he's beating the boat..which was more of my point and more on topic. I'm sure there are other ways to travel the distance with speed and COM forward.

 

 

[Bruce_Butterfield]

@wish, I'd say you're at about 30/70 weight distribution on front/back foot. Nate looks more like 90/10. That's one reason why he runs a few more passes than the rest of us.

 

Yes, I'm guilty of too much on the back foot also:(

[Wish]

@Bruce_Butterfield yeeup. It's been a little better as of late with boot modifications. Maybe 50/50 now... Work in progress.

[Adam Caldwell]

@Wish - @Bruce_Butterfield

Not to derail this thread completely....

 

Its not necessarily about "weight distribution". It's about COM position over the ski.

 

You could, in theory, push 100% on your back foot on a heelside turn with a lot of active tailslide, but still have COM over the front of the ski. And It's even possible to push 100% on your front foot, but still have the COM too far back on the ski. (Classic locked out front leg and ski tip high). In summary -"pressure" on the bottom of the feet, does not define COM position -not even a little.

 

BOTH ankles have to flex so the shaft angle of each shin bone is less then 90deg to the ski. That's the only way to get the COM in the normal plane as described in GUT 103 Moving with Efficiency. We will hit more details on that in the GUT300 "how to" articles,

 

Your ankles behave like a glider style rocking chair. Adequate freedom in fore aft ankle flex is crutial. Shaft angle of the shin (ankle flex) defines COM position over the feet, which then defines the skis attitude in the water.

 

If your into critiquing film, look more closely at the angle between the deck of the ski and the shins. That is what tells you about COM position and how efficiently you can generate speed and manage energy in the turns.

 

@ Wish - Keep hacking the plastic away ;)

[AdamCord]

@Greg Banish Very good questions. You've touched on a lot of different aspects of timing, kinematics, and general handle path geometry. Let me see if I can steer you in the right direction.

 

One of my first "Aha" moments came when I was skiing with Mapple years ago. The course was blown out (public Orlando lake) so we decided to free ski. I was amazed at his ability to put the rope on any line length and just make smooth, tight-line turns like he did in the course. When I asked him how he was able to know when he was wide enough, and when to turn, he said (paraphrasing here) "I don't really pay attention to the buoys in the course. I'm just skiing with the boat." This really blew my mind at first. What he was getting at is that he wasn't trying to get just wide enough to run the course. He would ski out until he hit the handle apex, reach, turn, and go back the other way. No buoys required. Of course because of how fast he swung, his apex was always very high.

 

In the same way, if we carry a lot of speed after the CL, yes we'll apex earlier in the course. But we also want to apex higher than we would if we are slow. The only time the handle should "dwell" at its apex is when we are reaching and moving out to the ski apex. Anything beyond that is not dwell. Normally what "feels" like a dwell at apex, is the result of us cutting off our upward swing prematurely (because we reached the buoy line and decided we must be wide enough, or we feel we are late and are trying to slow down), and starting to fall back on the boat. This cuts short the handle apex and also our move out to the ski apex. So we end up running parallel to the boat, at too low of a swing height, and generally too late in the course.

 

If we swing fast and high, we should be reaching a high apex before the buoy, so that we can be moving back inward with speed when we reach the buoy.

 

The truth is that we DON'T want to carry a lot of down course speed after apex. In fact the more we can slow our down course speed the better. BUT, we can't lose too much speed relative to the water, or we'll start to sink, drop in a hole, and take a big hit. So if we want slow our downcourse speed, but we don't want to slow our speed relative to the water very much, that means we must have a high cross course speed (inward toward CL) after the apex. In order to carry this speed and not get slack, we must be falling back on the boat early. Otherwise, if we are not yet falling back on the boat, we'll ski straight toward the pylon (which means we get slack). The only way to be moving back on the boat early is to apex high and early before the buoy.

 

This is why you see someone like Nate take a lot of angle out of the buoy, but he never takes a hit or gets much load out of the buoy. He apexes high and early, then carries speed inward as he falls back on the boat and picks up the line.

 

We're working on GUT articles that will go into all this in much more detail. There's a lot here but the goal of GUT sums it up. Take the handle high very fast, then once you get there, take the handle high to the other side very fast. Repeat. Repeat.

[Chef23]

Awesome stuff. Thanks to the Adams for putting this together.

[ktm300]

First, I cannot overstate how appreciative I am of the work and thought that the Adams have put into articulating these ideas. Second, while I understand and appreciate the methodical and linear roll out of the articles, please jump ahead and post your thoughts on the gate. A lot of us are starting to ski and it would be helpful to start at ...the start. Thanks

[Adam Caldwell]

@ktm300 - Patience. However I will give you this without derailing this thread.

 

The sequence of events for the "gate" starts well before you even pull-out for the gate. Be more aware of your position relative to the boat and what that means in terms of timing when you actually begin to roll into the "pull" phase during the final steps of the gate approach.

 

We are not 100% sure yet, but the specific HOW TO stuff may or may not be limited to Denali customers only via the community forum.

[mwetskier]

based on something i've been working on for the 2 last years i predict a significant aspect of the gut principle regarding carrying speed after the wake and ' up ' on the the boat is *lead arm* pressure after the center line. very interested in seeing if that prediction is right.

[aupatking]

Am I thinking incorrectly, that a good swing thought is "get to center line earlier"?

[chris55]

Thank's again for the article. I started slaloming seriously 2 seasons ago on a public lake and my first tournament was last year. I can run 30mph at 15off and my goal is to run 34mph.....I am starting this year with a new ski, a T2 (my old ski was a O'Brien Mapple from 2002 I think) and a lot of theory input from the Adam's and your articles make a lot of sense to me. I just don't know yet how to "anticipate" the gate and how critical is the gate skiing at my speed and long line.....

Is it okay to think that I have to bring the handle (and me with...) as close as possible to the exterieur buoy at the entrance gate ?

[IronR1]

If we want to be high and fast at the Apex and sustain the maximum speed around the buoy because we need it to obtain again the maximum speed between apex and CL, why do we have wings with a lot of angle on our fins?

[AdamCord]

@IronR1 Good question. I'm not sure if you read GUT-101, but it talks a little bit about down course speed relative to the boat. It's touched on again in this article and my post above where I said this:

 

The truth is that we DON'T want to carry a lot of down course speed after apex. In fact the more we can slow our down course speed the better. BUT, we can't lose too much speed relative to the water, or we'll start to sink, drop in a hole, and take a big hit. So if we want slow our downcourse speed, but we don't want to slow our speed relative to the water very much, that means we must have a high cross course speed (inward toward CL) after the apex.

 

So yes we absolutely need to slow our down course speed. But there is a difference between slowing our down course speed, and just slowing down in general. If we apex high and early, we can start to carry speed back toward the wakes. This means we are actually carving, and changing direction, so that our down course speed slows but we don't lose all our energy. If we apex late (at or after the buoy), then if we try to ski inward we'll get slack. So the only option is to drop to the tail, rotate the ski, and shut down all our speed. This works great for slowing down course speed, but then we start to sink, and we have very little momentum heading toward the wakes.

 

Putting a big wing on a ski and using a steep angle is a good way to make sure the line stays tight, but it also generally means you'll end up too slow, and with a lot of load as a result.

[chris55]

Sorry for not mentioning but my question was to @AdamCord or @adamhcaldwell. Since I am a beginner, it would help me just to say if I am thinking in the good direction or not at all. Thank you

[AdamCord]

@chris55 We're going to be releasing a lot of info about the gate, because it really is the most important part of the course. To ski with a high/fast rhythm, you need to start with this rhythm on your gate. It's very difficult to start low and slow, and then get fast/high later in the course.

 

The most important thing for anyone, no matter the speed or line length, is to create as much speed as possible before the CL of the gate. As we alluded to in GUT-104 above, getting higher on the boat will make it easier to generate this speed.

 

Of course it's not quite that simple. The guys who came down to the Denali Summit in November can attest to that. We spent 2-3 days with those guys working almost exclusively on the gate pullout! This was to allow them to not just get high on the boat before the gate, but to put them in a position to accelerate efficiently into the gate. Not that the moves are hard to do, but they are very foreign for most skiers. We also gave them a crash course in GUT, with no prior information whatsoever, which probably was a little ambitious of us. :#

[Than_Bogan]

prior information shminformation... Still the most educational day of skiing I can recall.

[chris55]

@AdamCord THANK you for your answer. It make pefect and logical sense to me

[Wish]

So just to add to how important and foreign (for me) the new gate was, that's pretty much all I did at the Summit for the most part. Just the set up pull out and glide... repeat. I did 3-4 simulations of this all the way down the course for multiple sets. Very few cracks at full passes. At home it was all about gates and drills drills and more drills. And I still fall into old habits from time to time. But what a difference when it goes right. How you set up behind the boat before any move outbound matters....at ball 2.