Finally...

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Re: Finally...

Postby blackthorn » Sat Mar 10, 2018 5:29 am

geoffda said
Of the rare examples of skiers who continuously tip, it is an even smaller number who can demonstrate this without grinding their edges.


What is the definition of grinding the edges and how does one recognise it doing MA?

I only think I know, hence the question.
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Re: Finally...

Postby Max_501 » Sat Mar 10, 2018 9:02 am

Grinding is when...

WNYSkier wrote:...the stance ski is so loaded, especially the forebody, that although it carves cleanly it is slow in the snow. You won't feel this as much on ice and really hard snow but it is evident to the user on softer surfaces. I think Harald gives a nice reference in the "Note to Racers" at the beginning of Essentials about using "just enough edge" (or just enough pressure) to be clean and on line.


Slicing is fast, grinding is slow.

The snow surface plays a big role in when grinding will occur. For example, very cold rocky mountain snow provides a huge amount of grip so it is very easy to grind when it is not wanted so I might back off on some of the Essentials to get the skis slicing. OTOH, if I'm skiing a steep pitch with hard fast snow I might crank up all the Essentials so I get some grinding to help control speed.
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Re: Finally...

Postby blackthorn » Sat Mar 10, 2018 12:17 pm

Thanks Max. I'm pleased I asked because I had it wrong. So grinding in a PMTS context occurs when there is more than necessary tipping of the skis using proper PMTS movements. It may be useful for speed control.
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Re: Finally...

Postby geoffda » Sat Mar 10, 2018 12:36 pm

Max_501 wrote:Grinding is when...

WNYSkier wrote:...the stance ski is so loaded, especially the forebody, that although it carves cleanly it is slow in the snow. You won't feel this as much on ice and really hard snow but it is evident to the user on softer surfaces. I think Harald gives a nice reference in the "Note to Racers" at the beginning of Essentials about using "just enough edge" (or just enough pressure) to be clean and on line.


Slicing is fast, grinding is slow.

The snow surface plays a big role in when grinding will occur. For example, very cold rocky mountain snow provides a huge amount of grip so it is very easy to grind when it is not wanted so I might back off on some of the Essentials to get the skis slicing. OTOH, if I'm skiing a steep pitch with hard fast snow I might crank up all the Essentials so I get some grinding to help control speed.

Excellent post from Max_501. The thing about grinding is that a grinding ski feels very stable and grippy and these sensations lead skiers down the wrong path. They start to think that you must aggressively push against the stance ski through the sole of the foot to get grip and bend the ski. You can usually pick out these skiers because they hold a stiff stance leg. Often they park on it, but some of them can keep building angles. The latter group may tip (or do something that looks like tipping) right up to the release, but the kicker is that they can't finish the turn with the stiff stance leg so they have to release too early. Since they can't bring the skis across the fall line because they can't finish the turn, they can' control speed. Might look cool, but it is flawed skiing. Understanding the difference between grinding and slicing is again largely developed through self discovery.
Last edited by geoffda on Sat Mar 10, 2018 1:00 pm, edited 2 times in total.
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Re: Finally...

Postby geoffda » Sat Mar 10, 2018 12:37 pm

blackthorn wrote:So grinding in a PMTS context occurs when there is more than necessary tipping of the skis using proper PMTS movements. It may be useful for speed control.

Not exactly. Grinding occurs when you push against the stance ski through the sole of your foot. The amount of push can be very subtle--particularly if it is intentional. Basically, you are causing your base edge to grind against the snow surface, increasing friction. You can cause grinding to happen with a late, aggressive turn that really loads up the ski--but only if the snow is grippy enough to hold when you do this. There is a fine line between simply resisting the forces being generated (while giving in slightly to keep tipping) versus actively pushing against the ski. This understanding is something that develops with experience over time.
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Re: Finally...

Postby Max_501 » Sat Mar 10, 2018 1:04 pm

Geoff is right on the money, the far majority of skiers that grind do it because of pushing on the outside ski.

Just to add a bit to this discussion, and this is a very high level nuance, we can also get a grinding edge by increasing pressure on the edge by ramping up certain Essentials like CB/CA. Racers in particular need to be careful not to overdue the Essentials or they'll be too slow.
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Re: Finally...

Postby blackthorn » Sat Mar 10, 2018 2:14 pm

These are all very useful comments.

So grinding is not just what I interpreted Max to say, but also "pushing off".

I really don't what to get into an epic pugnacious discussion ( and really this is a bit of a thread change ) but my interpretation gets to what I think that PMTS is about - never use your main muscular efforts to increase the distance between BOS and COM.
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Re: Finally...

Postby Marc » Sat Mar 10, 2018 2:23 pm

And "slicing":

h.harb wrote:Chatter is caused by the following: a dead ski in an arc, skid to grip happening late, or too strong alignment. A dead ski is a ski that can no longer slice or move forward through the arc. A live slicing ski is not a well know occurrence in skiing, because so few skiers can do it and fewer can explain it.

Slicing a ski is the ski moving forward along it's carving arc until release. Skidding doesn't have slicing, so you have to be carving to realize slicing. Park and ride doesn't create slicing either. If you are carving and you are still getting chatter then the answer is, pull back the skis, then as the ski starts to engage in the high C, transfer some weight back toward the heel under your foot. Just this amount of movement will cause the ski to move forward into a slice (if it's on a high enough tipped angle) .

Here is the caveat, if you don't increase your tipping angles it won't work, because as you move pressure back to the heel, the ski will run away and you will be in the back seat. OK, now HH says this is the physics. Forward pressure on a ski and increasing tipping angles, causes a great deal of friction from the snow or ice, because they drive the tip into the surface. Consider this your braking system. The more you tip and the more forward you are, the better speed control you will realize. If you let the ski slice you lose forward tip pressure. So you had better increase tipping to make up for the ski moving forward through the arc. These are all degrees of movement and you need to play with these movements. I know what it takes me to achieve this, but how much and when is up to you to figure out, because everyone is different. Last comment, this doesn't work if you push your feet forward, because you lose both forward pressure and increased tipping ability, when you push your feet forward.
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Re: Finally...

Postby skiffie » Sat Mar 10, 2018 4:45 pm

geoffda wrote:The latter group may tip (or do something that looks like tipping) right up to the release, but the kicker is that they can't finish the turn with the stiff stance leg so they have to release too early. Since they can't bring the skis across the fall line because they can't finish the turn, they can' control speed. Might look cool, but it is flawed skiing. Understanding the difference between grinding and slicing is again largely developed through self discovery.


This is all super interesting. Just to make sure I understand correctly because I'm having trouble visualizing this in my head - because the stance leg is straight they can't control speed. I'm with you up till tipping up to the release but with a stiff stance leg, but then I'm confused by 'this causes them to release too early'. Does this refer to not being able to arc the turn across the hill (because the stance leg is straight) therefore releasing while pointing too far into the fall line?
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Re: Finally...

Postby jbotti » Sat Mar 10, 2018 5:06 pm

Max_501 wrote:Geoff is right on the money, the far majority of skiers that grind do it because of pushing on the outside ski.

Just to add a bit to this discussion, and this is a very high level nuance, we can also get a grinding edge by increasing pressure on the edge by ramping up certain Essentials like CB/CA. Racers in particular need to be careful not to overdue the Essentials or they'll be too slow.


Probably best to remember that for most mortals that are not racing, fully ramped or maxed essentials is a very good thing. When you are not racing, going a little slower is fine.
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Re: Finally...

Postby geoffda » Sat Mar 10, 2018 5:55 pm

skiffie wrote: Does this refer to not being able to arc the turn across the hill (because the stance leg is straight) therefore releasing while pointing too far into the fall line?

Yes.
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Re: Finally...

Postby Max_501 » Sun Mar 11, 2018 8:25 am

jbotti wrote:Probably best to remember that for most mortals that are not racing, fully ramped or maxed essentials is a very good thing. When you are not racing, going a little slower is fine.


That is an excellent point!

On page xi of Essentials HH writes:

Racers need all the tools, but when used to perfection those tools produce edge hold and grip, not speed. This is fine for a recreational skier, but for racers there is a different objective:

Gliding with just enough edge hold, and edge hold without impeding gliding, are the secrets to winning race runs.


He then explains that cutting back on the Essentials to gain speed leads to mistakes and recoveries.

Most of us don't have the athletic ability to recover like a high level racer so using the Essentials to perfection should be the goal for PMTS students.
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Re: Finally...

Postby noobSkier » Mon Mar 19, 2018 7:50 pm

How does "slicing" and "grinding" relate to edge-locked carves and brushed carves? Are they same thing?
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Re: Finally...

Postby jbotti » Tue Mar 20, 2018 7:40 am

noobSkier wrote:How does "slicing" and "grinding" relate to edge-locked carves and brushed carves? Are they same thing?


The above references to slicing vs grinding both relate to edge lock carving in the race course. One has a light and fast touch the other is heavy and slow. Brushing the way we think of it is rarely used in a race course. Generally racers are trying to carve as many arcs as they can and when they can't they are stivoting to set up a carve for the second half on the arc.
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