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Need some Race Tune advice - Page 2

post #31 of 45
Quote:
Originally Posted by zentune View Post

   Naturally I agree Atomicman...in fact, at this point I consider 2*side "radical--

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

      --as in radically under beveledbiggrin.gif (I put this last part WAY down here to freak you out A-man!!devil.gif

 

 P.s. what the hell is a "bong"? Is that a new waxing technique?

 

      zen 

Wow, you made me nervous!eek.gif

post #32 of 45

I still maintain that the quality of the sharp edge is easily as important as the exact angle.

It is possible to sharpen a razor or knife over a range of angles and still get it sharp enough to shave with.

Base edge bevel is very important when determining the edge angle necessary for engagement.

Side bevel, not so much.

It is true that the more acute the angle on an edge, the easier it is to get it really sharp.

You guys have any data to back up your angle is everything hypothesis?

I can point to literature regarding cutting tools that back up my claim.

In cutting tools, the equivalent of side bevel is back relief and it is most important for chip clearance not cutting force.

Of course, in racing, everything gets taken to the radical limit and extremes are the norm.

Eah?

post #33 of 45
Quote:
Originally Posted by dakine View Post

I still maintain that the quality of the sharp edge is easily as important as the exact angle.

It is possible to sharpen a razor or knife over a range of angles and still get it sharp enough to shave with.

Base edge bevel is very important when determining the edge angle necessary for engagement.

Side bevel, not so much.

It is true that the more acute the angle on an edge, the easier it is to get it really sharp.

You guys have any data to back up your angle is everything hypothesis?

I can point to literature regarding cutting tools that back up my claim.

In cutting tools, the equivalent of side bevel is back relief and it is most important for chip clearance not cutting force.

Of course, in racing, everything gets taken to the radical limit and extremes are the norm.

Eah?

BSmeter.gif  Yes skiing on a sharp 2 and 3 degree back to back in a race course. A sharp 3 hold better than a sharp 2. No comparison!

 

3 degrees is not extreme! Base Bevel determines how when the edge engages, but diminishing the importance of side edge bevel, which allows the ski to hold once on edge is wrong!

 

I believe comparing how you sharpen your tools to how a ski works on snow are apples and oranges.

post #34 of 45
Quote:
Originally Posted by Atomicman View Post

BSmeter.gif  Yes skiing on a sharp 2 and 3 degree back to back in a race course. A sharp 3 hold better than a sharp 2. No comparison!

 

3 degrees is not extreme! Base Bevel determines how when the edge engages, but diminishing the importance of side edge bevel, which allows the ski to hold once on edge is wrong!

 

I believe comparing how you sharpen your tools to how a ski works on snow are apples and oranges.

Nothing wrong with calling BS if you can explain why.

Doesn't appear you can.

I'm aware of going as far a 5 degrees on SL skis but I would think one of you rocket scientists could explain this bit of dogma.

Challenging things that I cannot explain is one of the things I do.

When I find others cannot explain them then I become suspicious.

So, try again to explain why equally sharp bevels of 2 and 3 degrees ski differently.

Or, maybe you just can't really get a consistently sharp edge with your tuning technique.

I did say that it is harder to get a 2 sharp than a 3.

(actually, I do have an explanation based on cutting tool theory but I'd like to hear yours)

post #35 of 45

I don't really care why. I just know from skiing on dofferent side angles that a 3 hold better than a 2 a 4 holds even better than a 3 and the World cup guys have been known to use 5 & 6 degrees on Slalom skis on injected snow.

 

I don't care about the physics, the geometry the theorems, or the calculations. I have skied on them all. And again skied a 2 and a 3 degree back to back in a race course.

 

That is all the proof I need.

 

But here is some info from some industry experts with massive years of experience as ski techs and product managers for major ski companies.

 

Mike Desantis' Credentials:

 

Mike de Santis founded, owns and operates SkiMD. His experience is unsurpassed at the retail level, allowing the beginner through expert or racing participant access to factory level service. 20 years of continual development has created an ideal refinishing system that works for everyone.

While at Volkl, Mike was overwhelmed with the negative feedback on the company website from consumers in regards to their first “shop stonegrind.” The retail effort back then and now continue to be apathetic regarding the proper restoration and installation of tuning parameters. Realizing the need for someone in the ski service industry who could consistently deliver the proper finish to shaped skis and snowboards, is what prompted Mike to leave Volkl and develop the SkiMD Refinishing System.

Mike’s extensive background combined with 46 years in the sport of skiing, are instrumental to his success:
 


  • Graduate Stratton Mountain Ski Academy 79’

  • NCAA competitor UVM Ski Team

  • Physical Education Degree UVM 84’

  • 7 years World Cup Technician/ WC Race Director for Volkl

  • 4 years Product Development Manager for Volkl

  • Member Volkl International Test Team

  • Lifetime Achievement Award for excellence in the fields of World Cup Service and Product Development for Volkl Skis.

  • Technical service consultant for Volkl, Blizzard, Dynastar and Elan skis



Mike created his own proprietary finishes for top athletes such as Hilary Lindh, the 97’ DH World Champion. Kate Pace, the 93’ DH World Champion. Katja Seizinger, the overall World Cup women’s downhill winner many seasons over. Other athletes include Picabo Street, Kristina Koznick, Heidi Voelker, and former U.S. Snowboarding Team athlete Rosy Fletcher, Olympic Bronze medalist. Working in tandem with Volkl Germany, allowed Mike access to some of the very best factory technicians in the world. Combined with deep factory knowledge of ski design and construction, the foundation was built to create a system that has such a broad level of success. This is what truly differentiates SkiMD from all the rest.

 

Read his Side edge parameters!


 

http://www.skimd.com/parameters.php

 

 

As Division Manager of Blizzard Sport USA and personally responsible for all Blizzard product related issues, it is my responsibility to make sure that our products look, and more importantly, perform at the highest level. I have been on the product side of the industry for many years now, many of them with Mike. One thing I have learned during my time is just how crucial proper ski preparation is to the performance of any ski. The foundation of my knowledge has come from Mike. Something that you once said has always stuck with me and I have found it to be absolutely true, “Ski preparation is the easiest way to make a bad ski perform great and a great ski perform badly.” We, at Blizzard, have fully embraced your proven SkiMD ski preparation methodology and it has resulted in the tremendous on-snow success of our products at all performance levels. Your system has helped to produce back-to-back “Gear of the Year” awards from SKI Magazine and get the “Buzz” going on a brand that was stagnant just 2 years ago. Mike, please keep doing what you do so well, because you are the BEST of the best. I have been fortunate to learn from you and look forward to continuing to do so in the future.

Jed Duke
Division Manager
Blizzard Sport USA

 

Apparantly you think you know more than these guys or me or Zenny!

 

Sorry to burst your bubble, you don't!

 

And as far as MY tunes go, do even go there.
 

post #36 of 45
Quote:
Originally Posted by Atomicman View Post

I agree with what Van said if it were in regard to Base edge bevel, but side edge bevel? Nope!!! There is no negative to a 3 degree!

Sorry A-man wasn't implying that there was (I'm in your court on that one).  More to the fact that changing more than one thing at a time may not so wise, my bad for not stating it clearly.

 

Added in edit: This statement is more intended for someone that has little to some tuning experience (I'm personally sure that you and the seriously good tuners out there follow similar guidelines when setting up a high performance ski with the only exception you have a better idea through years of experience as to where to start so it is not a radical jump as it would appear).

 

G

post #37 of 45
Quote:
Originally Posted by oldschoolskier View Post

Sorry A-man wasn't implying that there was (I'm in your court on that one).  More to the fact that changing more than one thing at a time may not so wise, my bad for not stating it clearly.

 

Added in edit: This statement is more intended for someone that has little to some tuning experience (I'm personally sure that you and the seriously good tuners out there follow similar guidelines when setting up a high performance ski with the only exception you have a better idea through years of experience as to where to start so it is not a radical jump as it would appear).

 

G

No worries OSS, I thought you were agreeing! I was trying to make it clear for anyone who reads the thread in the future!

Thanks for the headsup!mad.gif

post #38 of 45

   Well. I finally have a quiet moment to form a cogent thought and put it to paper with penbiggrin.gif. Dakine has a "point" hereROTF.gif--couldn't resist the pun!--in that sharpness is probably just as important as degree. I'd much rather prefer to race an icy sl set on a very sharp .5/2 then a very dull .5/3. But..........this is only one side of the argument. If given the choice between a sharp 2 and a sharp 3 in the same scenario, I'm taking the 3. Why? To my mind it's all about acuteness. The more acute the angle (we're still talking about firm snow here), the smaller the effective contact point your edges have. The smaller this point is, the more easily penetration can be achieved due to the resultant increase in pressure imparted to the snow. This (and a good technique, of course!!) is what facilitates better grip" on the goods (which is what I call hard snow...sick, I knowdevil.gif!).

 

   The reason A-man , I, and many, many others will use a 3 side on an all mountain ski is that the 3 essentially has no effect on the soft stuff. So my Mantras, for instance, have a 1/3. I can ski the "soft stuff"  all day long with no detriment--but if I take it around to the "goods side" of the mountain, I've got enough bite to git er dun. 

 

    zenny

post #39 of 45

"

"Apparantly you think you know more than these guys or me or Zenny!

 

Sorry to burst your bubble, you don't!

 

And as far as MY tunes go, do even go there."

 

I treat you guys like the old mule joke...sometimes you have to hit folks on the head to get their attention.

 

Here is my thinking...if you don't like to think and discuss...that's not my problem.

 

A ski operates in two cutting modes.

When skidding it is much like a scraper and the relief angle on a scraper doesn't matter much only the angle of attack (edge angle minus the base bevel)

When carving it is much more like slicing with a knife and in a slicing cut the more acute the angle of the blade the less material it has to displace as it moves through the material.

With less displacement of material the cutting edge can sink into the material further at given force.

As applied to skiing a more acute angle would penetrate the snow deeper at the same normal force and give you more grip.

 

This is consistent with what I have observed in 40+ years of tuning skis with some great coaching by Othmar's tuner along the way.

What I have a hard time understanding is why such a small change in side bevel (like going from 2 to 3 degrees) has a significant effect on professionally hand tuned skis.

Then there is the microgrooving voodoo that WC guys do that seems to affect things significantly.

 

That being said a sharp 2 degree bevel is way better than a dull 3 degree bevel.

 

A bit more on the old Austrian that tuned Othmar's skis.

He had more tricks than most could imagine.

Using a scraper and freehand files he was doing everything (like graduated side and base bevel) you guys talk about over 30 years ago.

He also used a metal scraper to make some parts of the base concave and some convex...his skis were never flat.

 

So, lighten up Atomicman, getting personal when you can't explain stuff shouldn't make you pompus

.And, I still wonder if anyone can really explain why a very small angle change can have a significant effect on ski performance?

 

One thing I do think is that most skiers ski on really dull skis where the edge angles don't matter much.

That's why I maintain that edge quality is more important than angle for all but guys like Zenny (and me) that obsess over their boards after every use.

It doesn't matter if the edges are at X degrees of bevel if the edge is a radius.

 

Shakasmile.gif

Now, if there was a way to get skis molecularly sharp like a chipped obsidian blade you could dig trenches in race grade ice.

post #40 of 45

   Actually Dakine, I think Aman keeps his skis sharp an acute enough to cut a piece of silk if you were to drop it from above onto the edgeeek.gif. Sharp AND acute is best for hard snow to due the reasons I stated above (assuming carving OR skarving). If you prefer a sharp 2 side, well, that's up to you. My sl's have the variable base .7.5.25.5.7 and a 4 side--and I'm under no illusion that the variable base is something new. Tuning is part art, part science. Honestly, there really is no reason that less skilled skiers need anything under a 3...but at the same time, there's no reason they need a 3, either. What's of MORE importance to them is the BASE BEVEL, which should not be less than 1.

 

   Z


Edited by zentune - 4/14/13 at 7:56am
post #41 of 45

There is the question of edge durability at more acute angles but again I don't see why a very small change in angle should affect this much.

My skis are all at 3 and either .7 or 1.

Another significant variable is how far the base bevel runs into the base.

I've seen some skis with the bevel run almost a centimeter into the base.

I assume these are for improved gliding.

I once took an old pair and put as much side bevel on as I could get.

Somewhere between 5 and 10 degrees.

They would hook up incredibly but were near impossible to get into and out of a turn smoothly.

I wasn't smart enough to know much about base bevel then, the thinking was flat.

A tune of 10, 0 won't be used any time soon again in my shop.

Taking things to extremes is a good way to understand what affects what.

post #42 of 45

   From everything I've ever read, been told in person, and experienced myself, more acute angles don't dull faster than less acute angles in any appreciable or measurable way. That being said, if we ski hard snow all the time exclusively with the same pair of skis, they will dull quite rapidly, no matter what the angle. I've never heard of any one intentionally bevelling into the base itself...if we wish to improve glide in DH we apply higher bevel on the base edge itself, from say, 1.5-2+...Otherwise base high will cause too much drift...

 

   z

post #43 of 45

   Look for a new thread coming somewhat soon I'll start regarding ski shaping (has nothing to do what we are talking about now, tho)

 

     zennysmile.gif

post #44 of 45
Quote:
Originally Posted by dakine View Post

"

"Apparantly you think you know more than these guys or me or Zenny!

 

Sorry to burst your bubble, you don't!

 

And as far as MY tunes go, do even go there."

 

I treat you guys like the old mule joke...sometimes you have to hit folks on the head to get their attention.

 

Here is my thinking...if you don't like to think and discuss...that's not my problem.

 

A ski operates in two cutting modes.

When skidding it is much like a scraper and the relief angle on a scraper doesn't matter much only the angle of attack (edge angle minus the base bevel)

When carving it is much more like slicing with a knife and in a slicing cut the more acute the angle of the blade the less material it has to displace as it moves through the material.

With less displacement of material the cutting edge can sink into the material further at given force.

As applied to skiing a more acute angle would penetrate the snow deeper at the same normal force and give you more grip.

 

This is consistent with what I have observed in 40+ years of tuning skis with some great coaching by Othmar's tuner along the way.

What I have a hard time understanding is why such a small change in side bevel (like going from 2 to 3 degrees) has a significant effect on professionally hand tuned skis.

Then there is the microgrooving voodoo that WC guys do that seems to affect things significantly.

 

That being said a sharp 2 degree bevel is way better than a dull 3 degree bevel.

 

A bit more on the old Austrian that tuned Othmar's skis.

He had more tricks than most could imagine.

Using a scraper and freehand files he was doing everything (like graduated side and base bevel) you guys talk about over 30 years ago.

He also used a metal scraper to make some parts of the base concave and some convex...his skis were never flat.

 

So, lighten up Atomicman, getting personal when you can't explain stuff shouldn't make you pompus

.And, I still wonder if anyone can really explain why a very small angle change can have a significant effect on ski performance?

 

One thing I do think is that most skiers ski on really dull skis where the edge angles don't matter much.

That's why I maintain that edge quality is more important than angle for all but guys like Zenny (and me) that obsess over their boards after every use.

It doesn't matter if the edges are at X degrees of bevel if the edge is a radius.

 

Shakasmile.gif

Now, if there was a way to get skis molecularly sharp like a chipped obsidian blade you could dig trenches in race grade ice.

I'll take a duller 3 over a sharp 2.

post #45 of 45

the chips are down, nothing goes... will it be the 1? the 2 or the 3???

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