or Connect
New Posts  All Forums:Forum Nav:

Accelerating out of a turn - Page 3

post #61 of 235
I remember what a "break through" it was to be able to start off "skating" on ice or roller skates without lifting a foot to "push off". Just by the correct combination of wags and wiggles, I could start moving, Forward or Backward!

It must have taken a full day to "perfect the technique. But at 7 years old (or there about) We had all day to give to such a scienterrific investigation.

CalG
post #62 of 235
This weekend I got the ultimate proof that skis do accelerate out of a turn. I demoed Bandit B4s and took a powder-skiing lesson (yes, we have powder in CA these days; almost 2 feet in one day) At one point the instructor (LIII) told me to follow him, which I did, and when we came down to the lower flat groomed portion of the trail, he put his skis flat, while I was following about 15-20 feet behind before I started making long-radius carved turns. 5 turns later, I was ahead of him.
post #63 of 235
The Q is not wether it is quicker to turn or not to turn but how to accelerate out of a turn. If you think that WC skiers racing allways tryes to be as quick as possible you are wrong. Race sking is like race car driving, besides stearing its all about how well you controll your speed and how you use your brakes. Sometimes you need to accelerate out of a turn as faast as possible, the result of a successfull move at the previous gate, sometimes you need to scrub some speed off with a pre turn pivot in order to maintain optimal line. Not every move is made to go as fast as possible.

PM, on the issue of someone catching up others when carving it usually is because the guys infront dont carve as efficiently. Equipment and waxing plays a major role and not to be overlooked the fact that the guy chasing can usually take a shorter line, a line closer to the fall line.

If you make your carved turn right you will have lots of energy to spare. A good way of finding out how well you generate energy is to try to jump at the transition. Im not going to post my video clip again but its a very common racing exersise here in europe.
post #64 of 235

Carving Leapers

Quote:
If you make your carved turn right you will have lots of energy to spare. A good way of finding out how well you generate energy is to try to jump at the transition. Im not going to post my video clip again but its a very common racing exersise here in europe.
Right on Tom and it is a handy drill to have practised when you get caught hangin on that edge and there is a gate coming at ya Real good video with voice over instruction "Carving Leapers Drill" on Alpine Ski Fundamentals II at USST Coaches Education shop (Bode might even be one of the demonstrators : ) I didn't realize but this is actually a USST/PSIA collaboration, maybe we are going Italian over here after all : http://shop.usskiteam.com/store/prod...cat=251&page=1

- Fossil
post #65 of 235
Quote:
Originally Posted by AlexG
This weekend I got the ultimate proof that skis do accelerate out of a turn. I demoed Bandit B4s and took a powder-skiing lesson (yes, we have powder in CA these days; almost 2 feet in one day) At one point the instructor (LIII) told me to follow him, which I did, and when we came down to the lower flat groomed portion of the trail, he put his skis flat, while I was following about 15-20 feet behind before I started making long-radius carved turns. 5 turns later, I was ahead of him.
LOL. Funny. That doesn't mean you were accelerating. There are all kinds of reasons why you might have been going faster than him. Weight, wind resistance, wax, ski length, ski base tuning, all can play a major factor.
post #66 of 235
Quote:
Originally Posted by Flying Fossil
Right on Tom and it is a handy drill to have practised when you get caught hangin on that edge and there is a gate coming at ya ...
Heres my domestic flight : http://sports.topeverything.com/defa...tent&ID=2271E7
post #67 of 235
Quote:
Originally Posted by uncle crud
what, if anything, causes the feeling of a ski shooting forward beneath you when you time your unloading of the ski tails with the proper "finish" point in a particular turn?
skiing atomics
post #68 of 235
You can not create energy. Any speed that happens in a turn is the result of energy that has been managed and stored.

A racer (ski or auto), manages energy, only the auto racer can "create" energy with the right foot.

If the energy is not present on skis ... it is not going to be a happening thing ... period.

If you think that you can (out of nowhere or nothing), gain speed in a turn, two other forces are at work; illusion or delusion.
post #69 of 235
Ditto to what Yuki said...
post #70 of 235
Like I have been saying all along..... its just an illusion.
post #71 of 235
the energy you put into flexing the ski might "slingshot" you out of the turn.
post #72 of 235
Quote:
Originally Posted by mikey_10
the energy you put into flexing the ski might "slingshot" you out of the turn.
You might be able skate or get some momentum generated from your legs at very slow speeds.

Once you get going it doesn't take that much energy to flex your ski at any level of reasonable speed. Not enough to slingshot a 180 pound man with any signifigance. You can build a lot of forces under your ski and feel them slingshot you, but it does not have anything to do with the bending of the ski..it has more to do with the G-forces, your turn shape, how well you contain those G-forces and don't allow them to slip away through skidding or active absorbtion...and then when you "release" that energy it can slingshot you. But that energy has nothing to do with the bending of the ski, it is rather the power of gravity and momentum you are harnessing.

Using your thigh muscles or fancy footwork to somehow pedal a faster turn isn't going to do much unless you're Steve Austin.

(http://en.wikipedia.org/wiki/Steve_A...al_character)).

The only significant power input you have is gravity. Everything you do should be about maximizing the conversion of gravity into forward momentum. That is a complex subject. There are actually a zillion things you can do WRONG that will cause you to not harness the full power of gravity...or even worse, to increase friction or to allow momentum forces(which started out as gravity) to be lost through skidding or active absorbtion, etc.

If you feel like you're accelerating when you change directions then its because you're changing directions more than anything. Like when you're in your car and you take a corner at 25mph but it feels like you're going 40. When you change directions, you actually ARE acclerating in a new direction according to the laws of physics. And...if you're efficiently converting gravity into momentum..then that will accelerate you too.

There are a lot of techniques for this, maybe some of them are fancy footwork...but please understand..all you are doing is maximizing the efficiency with which you convert gravity into speed across the snow and minimizing the loss of momentum. Its also entirely possible that if you are trying to actively pedal your way to faster turns you may inadvertantly be making the conversion of gravity into momentum LESS efficient....not more... However, its also possible that you've stumbled on some fancy footwork trick that somehow does all of the things I just mentioned more efficiently. If so, I'll look for you on the podium. B=)
post #73 of 235
Simply restating an identical claim without new data or analysis doesn't convince anyone except people who only read the last couple of posts in each thread. :

As far as I can tell, the situation is completely unchanged from post #51 in this thread, where I said:

Quote:
"...you've got some folks on your side who say pumping doesn't work, basically because they either can't do it themselves or have never seen it done, and some folks on my side (one of whom is an L3) who either have done it themselves or have witnessed it being done.

Arguing that something can't be done because you haven't seen it done (or can't do it yourself) can be tricky because the reason it didn't happen could simply be that the people trying didn't know how to do it or were trying to "do it" under the wrong conditions (eg, too fast, too steep, snow was too soft, radius was too long, etc.).

OTOH, arguing that something can be done because you have done it yourself or have witnessed it being done is a lot easier to defend. In this case, if you're sure the witness hasn't missed a bit of a skating step or a pole plant and the guy making turns beats the guy going straight, it's a slam dunk.

I think what this really calls for is a field trip, somebody who says they can do it well (ie, not me), somebody else matched to person #1 in straight line runs, lots of witnesses (or a video cam), and lots of beer!..."
As I doubt you'll find too many people vetoing a field trip with lots of beer, I'm going to stand by MY last claim too.

Tom / PM
post #74 of 235
Admittedly I didn't read the whole thread...just the last few..but clearly folks are still confused so I think more explanation is justified
post #75 of 235
dewd - the folks who are confused probably didn't bother to read the thread i think we'd more or less agreed on an answer 25 posts ago

jinx
post #76 of 235
Well I don't hav it in me to read it all...so best of luck to you
post #77 of 235
Now, think about how you can "store" energy.
post #78 of 235
Quote:
Originally Posted by Yuki
Now, think about how you can "store" energy.
My preferred method is to store it as kinetic energy, though these days I seem to be storing more and more of it as mass (energy in stasis).
post #79 of 235
Quote:
Originally Posted by Yuki
If you think that you can (out of nowhere or nothing), gain speed in a turn, two other forces are at work; illusion or delusion.
Now that is pure gold!
post #80 of 235
Quote:
Originally Posted by PhysicsMan
Simply restating an identical claim without new data or analysis doesn't convince anyone except people who only read the last couple of posts in each thread. :

As far as I can tell, the situation is completely unchanged from post #51 in this thread, where I said:



As I doubt you'll find too many people vetoing a field trip with lots of beer, I'm going to stand by MY last claim too.

Tom / PM
Actually what you are missing is the obvious: The thread was about TURNING...I think it is and was a safe assumption that turning was to be defined as the way we ski (any system, CSIA, PSIA, PMTS etc etc)....does pumping work? Sure. But while pumping might work, it is less effective then just skating or poleing...so again I don't see what value you add other then confuse people.
post #81 of 235
Quote:
Originally Posted by Skidude72
Sure. But while pumping might work, it is less effective then just skating or poleing (sic)...
Aren't you saying exactly the same thing I said thirty posts ago, in post #53, where I said:

Quote:
Originally Posted by physicsman
Your comments on pumping not being applicable to racing fits dovetails with the previous caveats about pumping working best in relatively slow, shallow, short radius turns, and becoming less effective as you go faster, steeper and longer in radius, ie, the very province of the racer. While there might be some minor usability in parts of the course, you nailed it when you said that Jr. racers should never be misled by this & that there are lots of other things for them to be working on. Fortunately, I don't think too many will be misled.

I think this thread zig-zagged back and forth between trying to answer two distinct questions: (1) "Can it be done at all while skiing", and (2) "If it can be done, does it have much impact on competent amateurs' and racers' skiing". I think that's one of the major reasons for the confusion and seemingly contradictory points of view.

Quote:
Originally Posted by Skidude72
...so again I don't see what value you add other then (sic) confuse people.
If you want to maintain civil discourse, you should consider your choice of words more carefully when posting on this forum. To make this very easy for you to understand, would you enjoy me (or anyone else) telling YOU things such as (a) You apparently can't understand what you read, and that (b) I can't see what value YOU add to the forum other than to confuse people by going over the same material as if the issue had not been settled.

In one sentence, here is the primary rule for posts on Epic: Attacking ideas is fine, attacking people is not. This principle has been discussed a lot by the mods in the past week or two.

Do you understand what this principle means, and why it is important, or are you now going to launch into a rant on hypersensitivity?

:

Tom / PM
post #82 of 235
Ok...well someone missed their coffee today....I agree with your #53 post. Sorry, I missed your concession in post #53, we are on the same page on that one. But look at your post #73, which if somone (as I did) miss your qualifcation post #53 would be confusing....
post #83 of 235

Birds do it, bees do it

Well, maybe birds and bees don't pump, come to think of it, but bicyclists, skateboarders, snowboarders all do it among others...why not skiers? I've even seen people convinced that you can't pump a slalom skateboard, which is rather amazing given the ease of pumping that system.

For ski racers, or recreational skiers on groomed snow, it is true that pumping is a very minor part of the overall package. However, the ability to pump is closely related to possessing a dynamic, powerful technique overall, which is a rather central part of the overall package. To use a slalom skateboarding analogy, somehow those with the most powerful pump are also the strongest overal riders, even in courses that are too fast to require much or any pumping.

Further, you can also pump ruts, rollers, berms, bumps, and halfpipe walls among other things. Just as you can suck up ruts, rollers,berms, bumps and halfpipe walls. Here you are often on your base rather than cutting an arc with your edge, but the basic machanics are the same.
post #84 of 235
Hey PhysicsMan, I don't know why are you are so upset about other people wanting to continue giving their 2 cents or discussing it further.
post #85 of 235
Quote:
Originally Posted by dewdman42
Hey PhysicsMan, I don't know why are you are so upset about other people wanting to continue giving their 2 cents or discussing it further.
Their two cents so often seems to be, curiously, simply repeating that pumping doesn't work or that pumping is an illusion? For a forum that in many ways is centered on groomed snow and short carving skis in particular I find it curious that people wouldn't be all over something like pumping.
post #86 of 235

Like when wind travelling horizontally hits the slope of a hill the result is wind travelling a greater distance over the same period equals a higher speed up the slope??

post #87 of 235
Quote:
Originally Posted by dewdman42 View Post

Quote:
Originally Posted by mikey_10
the energy you put into flexing the ski might "slingshot" you out of the turn.
You might be able skate or get some momentum generated from your legs at very slow speeds.

Once you get going it doesn't take that much energy to flex your ski at any level of reasonable speed. Not enough to slingshot a 180 pound man with any signifigance. You can build a lot of forces under your ski and feel them slingshot you, but it does not have anything to do with the bending of the ski..it has more to do with the G-forces, your turn shape, how well you contain those G-forces and don't allow them to slip away through skidding or active absorbtion...and then when you "release" that energy it can slingshot you. But that energy has nothing to do with the bending of the ski, it is rather the power of gravity and momentum you are harnessing.

Using your thigh muscles or fancy footwork to somehow pedal a faster turn isn't going to do much unless you're Steve Austin.

(http://en.wikipedia.org/wiki/Steve_A...al_character)).

The only significant power input you have is gravity. Everything you do should be about maximizing the conversion of gravity into forward momentum. That is a complex subject. There are actually a zillion things you can do WRONG that will cause you to not harness the full power of gravity...or even worse, to increase friction or to allow momentum forces(which started out as gravity) to be lost through skidding or active absorbtion, etc.

If you feel like you're accelerating when you change directions then its because you're changing directions more than anything. Like when you're in your car and you take a corner at 25mph but it feels like you're going 40. When you change directions, you actually ARE acclerating in a new direction according to the laws of physics. And...if you're efficiently converting gravity into momentum..then that will accelerate you too.

There are a lot of techniques for this, maybe some of them are fancy footwork...but please understand..all you are doing is maximizing the efficiency with which you convert gravity into speed across the snow and minimizing the loss of momentum. Its also entirely possible that if you are trying to actively pedal your way to faster turns you may inadvertantly be making the conversion of gravity into momentum LESS efficient....not more... However, its also possible that you've stumbled on some fancy footwork trick that somehow does all of the things I just mentioned more efficiently. If so, I'll look for you on the podium. B=)


Like when wind travelling horizontally hits the slope of a hill the result is wind travelling a greater distance over the same period equals a higher speed up the slope??

post #88 of 235
Quote:
Originally Posted by vail99 View Post

Look people there is NO acceleration out of a turn- it has been tested and proven over the years. The more you load a ski to bend it into reverse camber (flex) the more the radius shortens and the more braking force is imparted on the turn. The "snap" you may feel of the ski releasing its energy is always going to be less than pure fall line skiing. Yes you may feel like you are accelerating but only because you have exerted such a braking force in the turn that when you re-enter the fall line in your transitional movement you feel like your speed is increasing. But again, this will always be less than a pure fall line straight run. Many of the analogies posted here as in the bike reference have no bearing on this issue.

Like when wind travelling horizontally hits the slope of a hill the result is wind travelling a greater distance over the same period equals a higher speed up the slope??

post #89 of 235

It is my understanding that the focus should be how to minimise deceleration due to the increased effects of friction due to turning and the decreased effects of gavity due to turning out of the fall line.

I'd challenge anyone to come out of a turn faster than the went into it. If this were so then you would surely see WC athletes sticking in an extra couple of turns to generate speed.

What is felt is percieved as acceleration but does not result in an actual increase in the skiers speed over the whole turn. The loss of speed is greater than the gain of speed due to any tail pressure, etc...

 

I'm all for choosing the best line, balancing on the edges and staying centred.

 

My concern with trying to teach any pumping, jetting, etc... is that the skiers focus would be taken away from more important things such as staying centred, quiet upper body......once these things are in place then sure why not investigate a little to see if we can do anything to go a little faster.

 

On water skis you will accelerate when you turn but this is because the boat has not slowed and the skier is covering a greater distance its not practical to compare water skiing to snow skiing because in water skiing you are being pulled by a boat and in snow skiing you are reliant on simple forces of nature - friction, drag and gravity.

 

I've not analysed any other sports but I'd be interested to see the physics of skateboard pumping. Its worth remembering that it may be possbile to make movements that make something move from standing but with skiing you already have momentum. Could you take a skateboard jump on it on a hill and do something to make it go faster at 20mph?
 

post #90 of 235

Perhaps the word "accelerate" is confusing people.  I like the posters description of storing energy in a ski like energy in a bow. 

 

The "acceleration effect" is produced by really "carving" the ski and loading it with energy.  Harnessing this energy upon releasing the edge and the "feeling" of being "shot" through the turn transition feels like "acceleration."  

 

Sometimes if you are unprepared, or the ski stores "too much" energy, the "shot" effect will "shoot" your @$$ into the air and this is not good.  Having achieved temporary low earth orbit, it sure FEELS like you are going faster.  UNFORTUNATELY since time ticks more slowly as you approach the speed of light, your brief suborbital flight seems to last forever and you have time to contemplate the landscape passing below.... until some part of your touches the ground again and you start to decelerate - rapidly - time reverts back to its normal duration and well...

 

Point is -  getting launched out of a turn will make you a believer in the "acceleration effect" :)

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Ski Instruction & Coaching