New skis, bases not quite flat

[J. Barron DeJong]

But why not at least try and send an email to Blizzard (or the shop you purchased the skis from) and see what they say?

There is obviously an acceptable tolerance to what is acceptable to Blizzard (and other ski companies) on base concavity so it can’t hurt to see if you would perhaps get a proper pair of skis at no extra cost and minimal amounts of time.

After that, if they refuse, then as you can see on this thread you can go a bunch of different ways based on your preferences.

But step one should always be an email back to the manufacturer or ski shop. It’s a no brainer.

My reason for not trying is because of what Wasatchback is describing - they’re all like that.

If you want to swing by the shop and get their input, maybe take a look at some of the other rustlers on the rack to confirm if they’re similar or not, go ahead. But if you have to send them back and be without skis for some time, I wouldn’t bother.

[tuco]

The amount of concavity that’s present in virtually all Rustlers does not affect performance in any way shape or form. How do I know? Cause I’ve tested it side by side with one ground completely flat and one just prepped by hand. There as zero discernible difference, in all sorts of conditions. That amount of concavity in the rockered section of a ski does not make it hooky, period. Same ski with camber, maybe but that depends on the ski and it’s construction.

It’s virtually impossible for any ski to come “railed” out of a modern factory. Not enough base bevel, yes… Railed, no.

Just about all factory tunes suck to some degree of suck. A lot of skis need to be ground in order to fix it but plenty can be easily modified by hand in 30 minutes if you know what you’re doing. Smoothing out the bevels at the end of the skis is usually all that needs to be done. I’d so much rather have a ski come with less base bevel, as you can easily add more by hand in 5 minutes. Skis with too much base bevel however need to be ground to be fixed.

And yes I’ve skied on hundreds of pairs of skis I’ve prepped. Test them every year to make sure the tweaking done by hand is correct. Don’t need to ski them all cause once you’ve found what works for each model you can do the exact same to everyone ski as there isn’t that much variance.

#1
Ive already stated that a ski does not need to be 100% flat. The edge needs to engage when the skier tells it to.
#2 I already stated that edge bevels should be reset and refinished prior to skiing OR tuning.

#3 Without skiing that ski pictured, you have 0 clue how it skis. Don't care how many Blizzards you've spun!
#4 My G3 Highballs were very very much railed and the degree of unskiablity multiplied w/ surface hardness. Highball is a fully rockered ski btw. So, actually, yes!
#5 I agree w/ your next paragraph, but then again I already stated these things.
#6i never said your "prepping" was wrong. Just that without skiing 1st, you didn't actually know how that pair skied. But I do agree w/ how you approached it. Reset bevels and refinish. Thats just common sense dude
BTW I used to prep G. Stevens demo fleet and worked under the Kastle demo tent @ quite a few demo days.

[tuco]

Oh, and 1 other thing.
I agree most factory tunes suck.
But @ msrp~9hundo to $1k, it's pretty fuckin butch imo to send out a ski that needs more work/$$ to make skiable, other than binding installation.

Also, rockered sections can very much engage the snow surface. There's all types of snow conditions out there. The one in which you describe rockered sections don't matter/engage snow is called 'hardpack' or groomers. Maybe you need to get off the piste a touch further

[RollGybe]

That ruler the OP was using in the pict looks kind of suspect from the angle we are seeing ?

IME that much concave was evil handing, I forget which I did first the stone grind or tail detuning

but it made a noticable difference

I knew we'd end here, the ruler is as flat as I can measure.
This is why I stated initially that the photo grabbed the light and made the ruler look bent.
At most, and this is really hard for me to measure, the concavity is 0.15mm - I feel better calling it 0.10mm based on the various pieces of paper I've gotten under it.

[RollGybe]

Very much appreciating the discussion here.
I see value in all this input!

[Todd Zander]

If it's really only 100 microns I'd just ski. I certainty wouldn't stone grind new skis for this.

Youre looking at it the wrong way, thats clearly 100,000 pm of convexivity. NOW do you see the problem?

[Mudfoot]

Over the years i have encountered several new skis that had railed edges. I figured they don't want the edges lower than the base and it is more expense to make them exactly level, so they error on the side of manufacturing them a little high. It you bought them from a store take them back and demand a free grind. If not, you can just flat file them. Come to think of it I believe Volant made their skis with the edges recessed from the bottom a bit

I have also found that it is not unusual for the bases right behind the tips to be concave. Not much you can do about it.

[Bosco]

Youre looking at it the wrong way, thats clearly 100,000 pm of convexivity. NOW do you see the problem?

That what I get for being an engineer... Never heard of picometer, but doesn't 100 microns convert to 1e+8 pm?

[Todd Zander]

I meant nanometer and I stand corrected. Irregardless what we are really dealing with here is 1,000,000 pm of base unflatness ugh the horror

Although on 2nd thought we really should be talking about slope in arc-seconds from ski edge to middle of base. What is the underfoot width of the ski in question

[Todd Zander]

More on flatness, which is more accurately described in terms of slope. For the purposes of this discussion lets talk in terms of arcseconds.

A ski with 102 width underfoot ( i assume thats where the picture in question was taken) at the midpoint is 51mm. If we really want to be accurrate here we should talk about the slope of the bases as having a whopping 395.9 arcseconds of roll. Unacceptable.

[J. Barron DeJong]

More on flatness, which is more accurately described in terms of slope. For the purposes of this discussion lets talk in terms of arcseconds.

A ski with 102 width underfoot ( i assume thats where the picture in question was taken) at the midpoint is 51mm. If we really want to be accurrate here we should talk about the slope of the bases as having a whopping 395.9 arcseconds of roll. Unacceptable.

Hey guys, you’re making all the engineers on here look bad. Sometimes you need to keep it in the closet!

[XXX-er]

These ^^are the same guys in uni that would sit around a table drinking beer giggling and arguing about the square root of pi

[hoarhey]

Funny, running into (possibly?) this same issue on my wife new pair of 2021 Atris 178cm.

She feel like the ski feels heavy and stiff on snow, is hard to control and throws her around and into turns. She's taken it to our shop for two sets of tip/tail detuning, but she doesn't think they've actually done it (she suspects they just resharpened the edge both times...) or that what they've done has had a difference .

My question is: what is the best next step? Is a base grind capable to "reset" everything? Should it go through the competitors shop's fancy Wintersteiger Scout?

They're replacing 2015 Atris 178's that she loves and has ~300 days on. Blackcrows press copy says her new version of the ski is *slightly* stiffer and the radius has grown from 18m to 20m, but the feedback she's giving is making it sound like it's an entirely different ski. The old ski is probably pretty beat and not very stiff, but she shouldn't be getting manhandled by the new one. My guess is something tune or construction-related is whack. WWMD??

Nick at Sunset in Snowmass mall has done good work for me. I’ve taken him my GPO’s and my new Praxis Sluggers (Sluggers were new)


Edit to add: maybe takes both pairs of skis for him to compare?

Sent from my iPhone using TGR Forums

[Todd Zander]

These ^^are the same guys in uni that would sit around a table drinking beer giggling and arguing about the square root of pi

Not me, i just work with alot of those types building really, really cool machines.

[Bosco]

Hey guys, you’re making all the engineers on here look bad. Sometimes you need to keep it in the closet!

Last I saw Pi was calculated to over 62.8 Trillion digits. How this has to do with the square root of Pi or the proper base flatness skis I don't know. I'm just a nerd that writes software for the metrology business. At the end of the day, just have fun and ski.

[J. Barron DeJong]

Last I saw Pi was calculated to over 62.8 Trillion digits. How this has to do with the square root of Pi or the proper base flatness skis I don't know. I'm just a nerd that writes software for the metrology business. At the end of the day, just have fun and ski.

I wasn’t the one who mentioned Pi. No offense intended, just a joke; I’m an engineer too.

[XXX-er]

Its ok, engineers don't really have a sense of humor

unless of they are giggling drunk arguing over the square root of pi

[tuco]

I knew we'd end here, the ruler is as flat as I can measure.
This is why I stated initially that the photo grabbed the light and made the ruler look bent.
At most, and this is really hard for me to measure, the concavity is 0.15mm - I feel better calling it 0.10mm based on the various pieces of paper I've gotten under it.

It's one thing to use that ruler as an illustration, but if you want accuracy, you should really use a truebar.
Have you rebeveled and skied them yet?

[RollGybe]

I know I should use a truebar. We could hammer away on my tools forever.



I'll ski them next week - haven't skied them yet.

[Todd Zander]

Which flavor is best suited for flatness? I imagine the RA on a cashew variety would be high as fuck.

[tuco]

I know I should use a truebar. We could hammer away on my tools forever.



I'll ski them next week - haven't skied them yet.

Not bustin on your tools.
You're trying to make some sort of precise measurement w/ imprecise tools. I guess I don't see the point of it

[RollGybe]

Ha, this ruler is flat, even if it's lucky. I knew knew knew things would devolve into this from the get go.

Anyway, little update from Blizzard. They will only discuss this through a shop, which is super annoying and what I expected.
In light of the company's response, I appreciate the conversation here even more. Thanks for all the input, even it there's been some disagreement.

[tuco]

You already had a response from somebody that works for Blizzard about 28 posts ago. He already told you those would not likely garner a warranty replacement and told you how to proceed.