or Connect
New Posts  All Forums:Forum Nav:

Atomic Tune

post #1 of 17
Thread Starter 
I just bought a new pair of the 11.20's. I asked about the correct tune and the store manager said the Atomics had a convex base from the factory. He was talking about more than the base edge bevel, he said to flat file the skiis to a perfectly flat base would ruin them. This seem really odd to me! Is that true. How would I contact an Atomic rep to verify? Thanks for any help or guidance.
post #2 of 17
Over the last two years there has been much discussion on this issue in this forum. BetaRacer is a contributor here and as the name suggests knows his Atomics (he is affiliated with them in some capacity). You could serch for his answers. Short answer though is don't do anything to them unless you ski them and they don't feel right.
post #3 of 17
I got the same story. In my case it was my wife's T:9 x's. As it turned out they were right... She's picky as allget out and she was inlove after one run!

You're right to question that based on conventional ski experience. It seems that there is a new tune and that we all have to adjust our thinking when it comes to mid-fat's and fatties.

The real question for us is how out of flat is too out of flat ? Egad...
post #4 of 17
I too purchased a pair of 11.20's recently and I was told that the area near the tip(and possibly near the tail??) was dished out or convex. Definitely not flat.
post #5 of 17
i was wondering this too.. but i forgot to ask when i left the shop.. i just picked up some 10.20s; i think they would be fairly similiarly tuned..

so what do you tell the guys at the shop when you take them in to get tuned? should i just get the standard treatment?
post #6 of 17
Just checked out my new 10.20 and there is a slight dip that runs from just back of the shovel (at the letter "I" down to the letter "T") and the same in the tail. The gap runs from 0.000" to about 0.015". Thanks for pointing this out!! Will get on the phone tomorrow and talk to my local shop. If I have any news, will post.
post #7 of 17
Back from a long research trip. What I've been able to gather is that the concave dip is a problem with all mid/fat skis from the factory. You can: 1) sand and grind the bases till they're flat (lose alot of base material), 2) just let the concave grind itself out with shop base grinds over the next few seasons.
Hope this helps...Art
post #8 of 17
Tognar tool works in their catalogue says that the problems with concave shovels and tails are a consequance of these areas being wider than was the case with conventional skis and more prone to becoming concave during the curing process. The issue is not confined to Atomic skis. Since skiers on shapes spend more time on their edges and less riding a flat ski it probably makes little difference.

I recently noticed that my Fischer SL's were slightly concave in the shovel area. I asked the shop to stone grind them flat. They got them nearly flat but were not all that keen on doing the grind because it does take down the edges and material. I asked them to do it mostly from force of habit because most of the years I've skied have been with conventional skis where a totally flat ski was the desired norm.
post #9 of 17
Artimus and Lostboy did good research. I had a customer who had this problem. I checked the ski and the problem was there. I took most of this out. There was a little concave left, but nothing to write home about. his Atomics now have the same concavity as my Mod X's. I have no problem with mine. I figured he'd have no problem with his. Plus, I didn't want to grind his bases into oblivion!
I work at Gart in Beaverton, Oregon. he returend a few weeks later and said the skis worked great! Had a big smile on his face.

Artimus- You're in Great Britain, right? When is the Queen going to let you come over to the colonies here and ski with me?
post #10 of 17
for an atomic tune, I like the Plutonium 5803 Tuning Table. electron synchronicity is much easier. beware the deuterium.

you know, Pons and Fleischmann were onto something.
post #11 of 17
This topic has been much discussed, with a fair amount of argument. Most skis are not flat when you buy them, regardless of brand. Some are almost unskiable because they're railed (very convex with the edges lower than the middle). I've known several people who bought Soloman's with this problem. My Head slalom skis were pretty convex and very grabby- totally unhappy with being off edge. It was like you were condemned to carving every damn turn and hockey stops were scary. Plus, the bases had no structure at all.
Unfortuneately, many shops just don't have the knowledge and will suggest remedies (as this shop did) such as detuning the tips. They also claimed they should be on edge all the time anyway. This just shows their lack of knowledge. I had to take mine to a different shop and get them flattened and stone ground. They're not perfect, but they're way better. The first shop blamed the problem on me and said they ran it through the machine. They didn't, it was exactly the same.
With such lack of knowledge by many ski shops it's no wonder the US isn't a force in ski racing.
As far as the Atomics go, the best answer I've gotten is try and get the base flat at least 1/4 of the width in from each side.
Trying to get it absolutely flat can often be too much work.

<FONT COLOR="#800080" SIZE="1">[ March 26, 2002 06:02 PM: Message edited 1 time, by Tog ]</font>
post #12 of 17
Thread Starter 
Thanks for the updates. The shop I dealt with said that Atomic had intentionaly designed in this clever convexity. Noticing my astonishment the manager started giving me a line about ski flex dynamics etc. I countered, that with that much flex on the ski, it would be so sharply on edge and so the base wouldn't matter. The manager then just threw up his hands and said he didn't design skiis. It really sounded bogus to me.
post #13 of 17
Do a search on "concave" in the gear section. You will get a bunch of hits.

From all I've heard, don't have the shop do anything until you ski them. If they are not "railed" (as in the edges are higher then the bases) or severly cupped they should ski fine. Leave them alone! The biggest change over the last several years that will continue to challange our paradigm of skis must be flat is the advent of wider shaped skis.
post #14 of 17
I recall well Betaracer's input on this. He said Atomics are designed with some concavity to allow the ski to become flat when skier weight and pressure are placed on it. He advised not to have a flat base grind, as it would substantially shorten the life of the ski. It does seem odd that other companies don't do the same thing, but then again K2's cracked edge concept seemed strange (and rusty at the cracks, after a few years). To be really sure, I would call or write Atomic USA before having anything ground.
post #15 of 17
If this is the way the manufacturers intended the base of the wide skis, how would they control or "tune" the things? How could the center of curvature be located on the centerline of the ski? Or are skis now "handed" as delivered. What if you got two lefts?
I know of no machine that will progessively grind the base from concave to flat as it goes fore to aft. (Such articulated stones exist for snow boards however)
Perhaps it doesn't matter, but it can't be engineered that way.
If skis are disposable, no tuning allowed, I guess it will be OK.

post #16 of 17
Thread Starter 
I'm a little confused as to how to tune these skiis in the future. However, for now I think I've gotten good advice in skiing them first before doing anything.
post #17 of 17
The idea that the ski base is supposed to be concave and it flattens out is ridiculous. I'm remember beta racer's comments on this and they just don't make any sense. He compared it to a leaf spring but a leaf spring is supported at both ends. Also there was a claim that Atomic invests millions in finishing equipment. Well Ford invests billions in car plants, does that mean their cars are perfect?
Fact is skis are "finished" before they're really ready to be. It just is not practical for manufacturers to store skis and then finish them when the glues have stabilized.
What's interesting is that they ski well with somewhat concave bases.

I'll post here the answer I got from someone who has a shop and tunes a lot of atomic skis for national level races too:

>>Many of the "discussions" on the Barking Bear site are about as logical as
dogs barking at the moon....

A concave base will not ski as well as a flat base. This is more pronounced
in firmer snow that is grippable than in soft snow where the ski does not
get a firm bite. Most manufacturers have difficulty delivering a finely
tuned product to the consumer for several reasons:
1 - Resins used in ski manufacturing tend to cure for some time after the
ski is produced which can cause a ski to take on an irregular shape. It is
simply not practical for the manufacturer to set unfinished skis aside for
several weeks for curing before doing the final grinding to flatten the
2 - Finishing processes at the factory level are entirely by machines which
change during production runs. Machines must be constantly "dialed in" as
their abrasive drums or discs wear away. Different sidecuts and sizes
(thickness and length) also require changing setting on the machines to
deliver some degree of uniformity.

Atomic tends to ship concave skis. This is probably because the Beta shape
with the higher humps tend to put more pressure in the center of the ski
when the ski is fed through a grinding machine with a pressure wheel on top
of the ski. Their base edge bevels also are quite erratic as they
consistently vary between 0°- 3°. I believe this is caused because the
automatic bevel machine cannot grind the edge where the ski base has any tip
curvature. Therefore, the skis usually have no bevel in the extreme forward
contact point and then tend to pick up a 3° "divot" immediately after the
bevel machine makes contact with the ski.

Our solutions:
1 - "If it ain't broke, don't fix it." Many "imperfect" skis perform quite
well depending on the skier and snow conditions.

2 - Make certain the base bevel is at least 1° with a guide,
file and polishing stone. Don't worry about slight irregularities of
increased base bevel unless you feel performance is being compromised.

3 - Erratic behaving skis are ground to somewhat flatten the tip area. We
grind with only hand pressure on the ski to eliminate the concavity caused
by the feed wheel putting pressure on the center of the ski. We consider
the ski to be flat when it is flat about 25% in from each side. A slight
tunnel in the center does not have any adverse effect. We then use guides and
hand tools to establish 1° base and 3° side bevels. Edges are polished and
deburred. If the ski is still hooky you might try a 1.5° base bevel in the
forward 15-25cm to soften immediate edge contact in the extremity.

4 - Many erratic behaving skis are actually the result of improper boot
alignment or canting.

Atomic's World Cup results are not a result of skis that are concave in the
tips other than the slight tunnel as described. Race skis are meticulously
tuned to perfection by ski team techs and don't resemble what is on dealer
shelves. Speed skis are usually a little convex because bases glide faster than
edges and you don't need or desire immediate edge hook-up at high speeds. << end quote

Does this settle the issue?

<FONT COLOR="#800080" SIZE="1">[ March 30, 2002 05:21 PM: Message edited 2 times, by Tog ]</font>
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Ski Gear Discussion