turn radius and chattering

[liquidfeet]

This is a technical question.

1. assume a 125-140 lb woman skiing
2. with skills level 7-8, skiing dynamically, edges appropriately up, turns initiated early
3. on an empty blue groomed slope in NE in the mid-morning
4. homemade snow underfoot, last natural was 2 weeks ago
5. she is attempting to ski this slope non-stop as fast as possible
6. thus she's using medium radius turns, skiing a narrow line, lingering in the fall line for speed
7. Plan A - she's on short slalom skis, 154's, published turn radius of 12mm or so
8. Plan B - she's on gs skis, 160's, published turn radius of 16mm or so


What will be the difference in how the Plan A skis and the Plan B skis grip the snow? Will one chatter or skid out, while the other holds true?

 

[liquidfeet]

Here's some further clarification of the original question:

If a slalom ski has a deep sidecut, and the skier puts it up on edge and weights it appropriately, it will want to cut a turn through the snow with a short radius, plus or minus some small amount. However, if that skier forces that slalom ski to perform a turn with a radius larger and outside this this range of mms, and he/she holds it in the fall line longer than it wants to be, it seems that the ski will grap/release, grab/release.

True? If yes, wouldn't a different ski, one with a wider waist and a larger turn radius, act better with such a turn?

And wouldn't a longer ski offer more ski/snow contact and thus more gripping power while following a narrow line that is skied fast?

 

[tcarey]

Looks like you have gotten some pretty good responses here https://forums.epicski.com/showthread.php?t=45867 LQ?

We at ski school have had many discussions about chatter. One belief is that the outside ski has too much pressure on it and is no longer moving forward.Correction would be to ease off the pressure on the outside ski and feather it again on to it's edge.

I am a believer that it is ultimately the input of the driver of the ski is how the ski will react!

T

 

[ISki]

I don't say much on technique or gear because I am old school. However, for what its worth, the old rule of thumb was that soft skis chatter at high speed. Longer skis are more stable.

 

[liquidfeet]

Almost every skier I ski with skis on longer skis than me. When I bought these, the salesman told me that I was lightweight therefore needed short skis. Maybe that's so, maybe not, but they are great for short aggressive turns on choppy soft snow. I can rhythmically zoom my way down a slope with fresh bumps (that have been made that day) quite well, working the rebound and having a blast. I can also go in the superpipe with them, while my very experienced friends with long skis won't go near that thing.

It's these straight and narrow speed runs that I have difficulty with. I don't feel like my skis are embedded in the hard snow enough to give me confidence. Thus the phrasing of the question.

I was beginning to wonder if anyone on SkiDiva was going to respond! Thanks.

ps: I got mm mixed up with meters. So embarrassing, but typical. The skis have a published turn radius of 12.5 meters, to be exact.

 

[ISki]

...I don't feel like my skis are embedded in the hard snow enough to give me confidence...

That sounds like skidding, not chattering. Skidding is okay in my book. Skid and make your next turn anyway. Longer skis with nice sharp edges do have more grip.

Chattering is when the ski vibrates up and down while it's being skied fast. When it chatters you know it. Stiffer skis do not chatter as much as softer skis.

 

[snowflake]

Let me ask you...are you feeling chatter...
ie. When you're making a hard carved turn on hard snow the downhill ski is almost making little hops.

Or are you feeling the ski is unstable...
ie. You're going at higher speeds and the ski feels like it wants to move side to side, kind of wiggling just a bit...hard to explain...

A shorter ski will be easier to turn, but at higher speeds can be a bit unstable. Especially if you're riding the ski flat, or not on edge.

 

[tcarey]

Let me ask you...are you feeling chatter...
ie. When you're making a hard carved turn on hard snow the downhill ski is almost making little hops.

Or are you feeling the ski is unstable...
ie. You're going at higher speeds and the ski feels like it wants to move side to side, kind of wiggling just a bit...hard to explain...

A shorter ski will be easier to turn, but at higher speeds can be a bit unstable. Especially if you're riding the ski flat, or not on edge.

Snowflake,
When I think of chatter I think of what you say in your first sentence.The ski start hopping laterally down the hill, the leg will shake along with the ski-so the ski has stopped moving forward-relieve some of the pressure and move ahead.Go to the next turn!


T

 

[liquidfeet]

Snowflake, I have not felt the "unstable" feeling you describe.

Chatter for me is a rapid fire grab-release-grab-release-grab-release of the tips. The skis travel fine, no shifting left and right, but they provide a tenuous and unfulfilling ride as they glide unrailed-railed-unrailed-railed. Like teeth chattering, that fast. Annoying at worst. Chattering does not usually leave me feeling insecure, unless it's on frozen rock solid inconsistently bumpy snow; then I'm worried.

By skidding I mean normal skidding ... the skis travel in direction A, but they are pointed in direction B. Controlled skidding is when I know how reliable the skidded grip is, and I ski with the skis skidding anyway. Anytime I am skidding I would prefer to be carving. Carving provides more security, especially at fast speeds.

These descriptions of skidding and chattering are what I felt numerous times last season whie following "the boys" who were flying down the slopes. But honestly it's been a while and I can't identify exactly when I felt chattering and when those darn skis were skidding. Suffice it to say, I needed better technique, but maybe different skis would have also been a good idea.

Say more, Divas!

 

[dburdenbates]

If train A leaves the station at 4:45 and travels 6 hours at 60 mph and train B leaves at 5:00 at 45mph, where will the mass destruction occur?

I always hated word problems!

Sorry I have nothing to add, but the original question made about as much sense to me as the one I typed up. :o

 

[snowflake]

liquidfeet,

What I have found with quite a few of my students, and myself is that when I apply too much pressure too quickly on the second half of the turn I then get chatter.

To fix this what I have my students try is to be more progressive with their pressure moves. Trying to be at full extension at the apex of the turn, then flexing progressively throughout the rest of the turn. All the wile steering the skis.

Does this make sense?

 

[liquidfeet]

Makes sense. I need to go outside right now and try this. Oh darn. No snow.

But seriously, I want to check to see if that's the problem. Will park this information in my folder of advice and earmark it. I do that ... make folders of advice. Does anyone else do this? How freakish and pathetic can it get?