New Posts  All Forums:Forum Nav:

To stone grind or not

post #1 of 28
Thread Starter 
I got new skis for my son - darn kid won't stop growing.  He's a pretty good skier and he's 10. He'll be participating in a twelve week instructional program this year with an emphasis on building skills and they'll be doing some racing as well. Should his skis have a stone grind done on them before getting started?

For that matter, should I have my wife's and mine done as well? They've never been done either.

Pardon the noob question. Just starting to get into tuning and would like to get the season off to a great start.

Thanks!
post #2 of 28
Are we talking brand new skis, never seen snow or are we talking 'new-to-me' possibly skied through a parking lot by the previous owner?

If new, there is no need to have them ground. They should be OK from the wrapper, if FIS points were on the line and you were looking for the best possible performance from a high-end ski (race stock skis come un-tuned), then sure, starting off with a flat base and your own choice for edge angles would be the way to go. If I were you I'd concentrate on keeping the edges sharp and the bases waxed, maybe a slight detune at tip and tail on brand new boards. By all means, have the skis tuned during the season as needed, but you don't need to start with a tune on new skis.
post #3 of 28
Run a true bar down the bases.  That should tell you if they need a grind.  
post #4 of 28
I have paid my ski-tech dues and belted my share of kid's skis. The cheaper the kid ski the more Concave it is. Imagine the worst railed ski you ever rode and then reduce your strength down to kid size.  Right out of the wrapper, a check-file is the only real way to feel what the whole edge is doing. Then as needed - Grind 'em and file them and wax them. Your kid will save many seasons in the learning curve. Kids race skis-  junior gs and sl's-  are better because they are adult skis for little people. Apply the same standards to their skis as you would - not to your own equipment, or you wouldn't be asking - but to a full-time technical skier's. Base bevel is key... assuming the ski is right for weight and ability- and THE most important factor in deciding a ski's performance.  Also - buy used equipment and tune it for fifty bucks. Kids out-grow race equipment and used GS can be found for $100. Later buy used Race-skis for $150- 200, because the Training skis take the beatings. With plates, reusing previous bindings is easy.
post #5 of 28
Just a note of agreement, based on a number of experiences with kids' skis, often the edges are pretty railed (and yes, it does seem that's less likely with race skis).

You can tell with a true bar, or just put them base to base and gently rub them against each other side-to-side.
post #6 of 28
Thread Starter 
They are new Atomic Race SL 12s - but leftovers from 2008. I had help from a kid's race coach picking them out. Although they say they are race SL they really have a GS radius.

I will check the flatness of the bases once I get them back. They are in for a binding recall now - they need a new toe piece. I though that you also do a stone grind to impart structure to the bases so they'd take wax better?
post #7 of 28
Quote:
Originally Posted by RossiGuy View Post

 I though that you also do a stone grind to impart structure to the bases so they'd take wax better?

Not necessary - there are ways to add structure that don't require taking the base and edges down.  The way I see it, you only get so many stone grinds per pair of skis so I avoid them unless necessary to level the bases.  
post #8 of 28
Thread Starter 
So perhaps just using a steel brush on the bases if they're already flat would be the way to go?
post #9 of 28
Quote:
Originally Posted by g-force View Post

I have paid my ski-tech dues and belted my share of kid's skis. The cheaper the kid ski the more Concave it is. Imagine the worst railed ski you ever rode and then reduce your strength down to kid size.  Right out of the wrapper, a check-file is the only real way to feel what the whole edge is doing. Then as needed - Grind 'em and file them and wax them. Your kid will save many seasons in the learning curve. Kids race skis-  junior gs and sl's-  are better because they are adult skis for little people. Apply the same standards to their skis as you would - not to your own equipment, or you wouldn't be asking - but to a full-time technical skier's. Base bevel is key... assuming the ski is right for weight and ability- and THE most important factor in deciding a ski's performance.  Also - buy used equipment and tune it for fifty bucks. Kids out-grow race equipment and used GS can be found for $100. Later buy used Race-skis for $150- 200, because the Training skis take the beatings. With plates, reusing previous bindings is easy.
Excellent comments.  Being an old ski tech myself, I was just telling my brother the exact same thing regarding his kids' skis (4 & 6).  He had picked up skis for this season at swap (looked in good shape) but the bases were incredibly railed.  I did what I could by hand, but told them to get them into a shop for a basic grind, nothing fancy, just enough to get the bases flat so they can be easily maintained by hand.  It will make a world of difference to his kids' experience, as you described.
post #10 of 28

Unless something very odd is going on, they come from the manufacturer with structure. The purpose of structure is to make the skis run better / faster, not really to make them take wax. While there are skiers who might get a base grind to give the skis the ideal structure for the local or seasonal snow conditions, if any of those skiers are ten-year-olds in a program designed to build general skills (as opposed to, say, J1s in a program designed to get their FIS point into the low double-digits), something is awry.

If the basic geometry is okay - which, given the fact they're a nicer model, may be the case - I would just wax them. No need to fool with a steel brush beforehand. You can check for railed edges pretty easily.

The bases may be slightly concave near the tip (see various other threads on this subject). That's most likely okay (again, see other threads), so long as the edges are level with the bases and have something in the neighborhood of a 1-degree bevel.

post #11 of 28
Thread Starter 
Thanks guys! I'll check the bases when we get them back - hopefully tomorrow. If they're flat we'll wax 'em up and be ready to go Saturday. The boy (and the old man) are chomping to get back on the snow!
post #12 of 28
Quote:
Originally Posted by Bob Lee View Post

Run a true bar down the bases.  That should tell you if they need a grind.  
OP, this is only true for your adult skis.

For entry-level to middle-of-line jr. skis, the base is almost never true, even brand new. Unless it's badly out of true or the base has been through a lot, I wouldn't bother with a grind and frankly it really wouldn't matter for the young skier. Just throw on a couple of coats of wax when it goes dry. Also keep in mind that these lesser quality jr skis don't usually come with much of a structure so expect wax retention to be poor.

Quote:
Originally Posted by RossiGuy View Post

They are new Atomic Race SL 12s - but leftovers from 2008. I had help from a kid's race coach picking them out. Although they say they are race SL they really have a GS radius.

I will check the flatness of the bases once I get them back. They are in for a binding recall now - they need a new toe piece. I though that you also do a stone grind to impart structure to the bases so they'd take wax better?
Now knowing that. The SL12s will be in good shape unless it was stored at a poor location. The bases will be close to flat. You may have to set the edges as some jr race stocks come with unset edges (especially the side bevels).

Also, just a word of caution... Your definition of "pretty good skier" now matters. Like I said, the SL12 is classified as a race stock so it's known to be very stiff in comparison to all other skis its size. Make sure your kid already has excellent skiing skills and he's not in the back seat. Also, some level of aggressiveness is required when skiing on race skis or he will struggle with his skiing and progression.

Lastly, DO NOT stone grind these brand new skis. Race stocks usually come with good structure already. A stone grind will unnecessarily lose material, lose the factory structure and lose the factory applied wax. You will end up redoing everything that has already been done at the factory. After you set the edges (if needed), then doing a light scrape, brush, and apply a couple of coats of el cheapo hydrocarbon waxes.
Edited by chanwmr - 12/8/09 at 8:29pm
post #13 of 28
 
Quote:
Originally Posted by Bob Lee View Post

Run a true bar down the bases.  That should tell you if they need a grind.  
 
Quote:
Originally Posted by chanwmr View Post

OP, this is only true for your adult skis. 

For entry-level to middle-of-line jr. skis, the base is almost never true, even brand new. Unless it's badly out of true or the base has been through a lot, I wouldn't bother with a grind and frankly it really wouldn't matter for the young skier. 

Just curious, how are you going to know if the base is badly out of true, or the edges are railed if you don't run a true bar?  It's not like that's an involved process.  
post #14 of 28
Quote:
Originally Posted by Bob Lee View Post

 
 

Just curious, how are you going to know if the base is badly out of true, or the edges are railed if you don't run a true bar?  It's not like that's an involved process.  



 
Well, not everyone has a true bar at their disposal. So, because we are still talking about hot waxing here, we assume that there is a plexi-glass scraper that is in good shape nearby. The person doing this would notice out-of-true-ness and railed edges (not to a high precision of course) as soon as he/she runs the scraper down the length of the skis. If not then, during ironing for sure. This process is sufficient for a pair of jr skis (definitely jr) IMHO.
post #15 of 28
I started out to correct (or at least chip in my perhaps ill-formed opinion on) a few points, though it made a few questions arise:

- Structure doesn't help a ski retain wax. It just helps it slide.

- All SL12-model skis are not, by definition, "race stock." Atomic sells non-race-stock SL12s (a fair number of them, I suspect).

Also, and maybe more importantly, keep in mind that - as is the case with most ski makers - Atomic re-uses model names for adult and junior skis. There's an adult SL12 (ordinary retail model, as well as a number of "race stock" variations, some of which would be hard to come by indeed), and a junior SL12, which is cosmetically similar, but not the same ski. The junior SL12 comes in shorter lengths, is softer, has different side-cut and construction, etc. If it's like a lot of junior skis, it doesn't even come out of the same factory, but out of one in Eastern Europe.

Here's where I started to worry a bit. An adult SL12 intended for women is ordinarily 155 cm long. It is certainly possible for someone, based on length, to make the mistake of thinking it's a ski for a young kid, which it is not.

Also - even the junior SL12 is at the top of Atomic's junior-race-ski line. I might worry that, even though it's a junior ski, it's more intended for a 12-year-old with some weight and gate-training in him, rather than a 10-year-old. There are some more foregiving variants (Race 10, 8 and 7) which could be more appropriate. Then again, Atomic seems to reshuffle how they use model names in junior skis from year to year.

And I note that the OP said the skis were picked with the help of a junior race coach. If he's a coach with any signficiant experience and expertise, he shouldn't steer you wrong. If he had the benefit of seeing the actual skier and ski, he's in a lot better position to judge than any of us.
post #16 of 28
Quote:
Originally Posted by Bob Lee View Post

Just curious, how are you going to know if the base is badly out of true, or the edges are railed if you don't run a true bar?  It's not like that's an involved process.  

Quote:
Originally Posted by chanwmr View Post

Well, not everyone has a true bar at their disposal. So, because we are still talking about hot waxing here, we assume that there is a plexi-glass scraper that is in good shape nearby. The person doing this would notice out-of-true-ness and railed edges (not to a high precision of course) as soon as he/she runs the scraper down the length of the skis. If not then, during ironing for sure. This process is sufficient for a pair of jr skis (definitely jr) IMHO.

So, assuming a true bar, it can be a good idea to check the bases and edges?  That's no the impression I got from your initial reply where you wrote: "OP, this is only true for your adult skis." 

And FWIW, from the thread title I thought we were talking about stone grinding more than hot waxing.  
post #17 of 28
Thread Starter 
Thanks for all the comments!

I'm fine with discussing the waxing as well as the stone grinding. From the sounds of it I have a decent ski that may not need much done to it. I need to get them back and then can check the bases out. I do have a decent scraper that's almost new but not a true bar yet. I'll be ordering one of those once I get my list together of what else I think I need. Just starting to build the tuning arsenal...

The SL12s we got were picked for him by a local race coach who hasn't seen him ski yet. They are 130s but I have no idea where they were made. The instructor he's going to be skiing with recommended we talk to this specific coach to have him pick the skis. Both of them are well known at our mountain. My son has enough ability to carve on blues and can get down blacks with little difficulty but he's not really carving them yet. He ended up qualifying for NASTAR nationals last year racing a total of eight runs last year. (Our home mountain doesn't have NASTAR.) The race coach took a look at his old skis and said "he made it to Nationals - skiing with those!?!" They were a basic kid's Rossi.

I've been trying to find a picture of his skis but haven't had any luck...
post #18 of 28
Thread Starter 
Found a picture if it helps...

post #19 of 28
Rossiguy,
Looks like these are the guys you have from the 09 model year:
http://www.ski-depot.com/miva/merchant.mvc?Screen=PROD&Product_Code=A085024&Category_Code=atomicskis2009&Product_Count=6

sjjohnson was right about Atomic reusing the jr SL11/12 label from year to year for different level skis but these designators are still reserved for jr race skis. In that year, this model is placed between the high end SL12 FIS and the next lower end Race 10. All these skis are designated as jr race skis suitable for true USSA jr racers. For a 10yo, it's probably more appropriate to use the Race 10.

My smaller younger then 9yo used the Race 10 as a dual event last season. These skis were by far better than any other dual events that I have worked with (Elan and Fischer) and same thing can be said about the construction. Also, the side bevels were factory set to 3 degs, which is very unusual for a ski that is 120cm long. From that, I deduce the SL12 to be at least the same in quality and what I have said previously about jr "race stock" (i.e. stiffness, aggression, etc.) still applies.
post #20 of 28
Quote:
Originally Posted by Bob Lee View Post




So, assuming a true bar, it can be a good idea to check the bases and edges?  That's no the impression I got from your initial reply where you wrote: "OP, this is only true for your adult skis." 

And FWIW, from the thread title I thought we were talking about stone grinding more than hot waxing.  
 
In a nutshell, I said "true bar is not necessary for jr skis because a good scraper is good enough. Don't stone grind new jr skis (especially race skis) but DO hot wax them. During wax, any exaggerated defects in the skis will become evident.". How was I diverting the thread or contradicting myself?
post #21 of 28
Quote:
Originally Posted by chanwmr View Post

In a nutshell, I said "true bar is not necessary for jr skis because a good scraper is good enough. Don't stone grind new jr skis (especially race skis) but DO hot wax them. During wax, any exaggerated defects in the skis will become evident.". How was I diverting the thread or contradicting myself?

  In  nutshell, read my post #13 and your post #14.  I said use a true bar and it will tell you if you need to grind.  You wrote "This is only true for your adult skis."  Then you wrote "...we are still talking about hot waxing here..."
post #22 of 28
Thread Starter 
Thanks for the info on the skis chanwrm. I hope to get them back today and we'll see how he does with them this weekend! I got a good deal as I paid $129.
post #23 of 28
Hey Rossiguy, Bristol opened yet? I've never skied there but might be there once this season.
post #24 of 28
Thread Starter 
They opened Tuesday with just green terrain. I'd bet they'll have a few blues and blacks open by the weekend based on the snowmaking they've got going. Plus a new high speed quad (#2) this year!

Let me know if you make out this way! Where's your home mountain?
post #25 of 28

All the things that apply to any ski also apply to Junior skis. if they are way out of whack, concave or convex or edges higher then base or way too much base bevel. They need to be stone ground. In order to put a reasonable tune on any ski the base has got to be flat at a minimum 10-20mm  in from each edge.

Chanwmr, can't really understand your comment about Adult skis and not to grind a Jr. partiularly race ski??? And these are not any way shape or form RACE STOCK skis! they come beveld from the factory, but as a Junior ski most likely need some work!

 

they are definetly a Junior ski. Did you see the OP's comment that they have a GS sidecut!

 

The Junior Gs12 & SL12 have the same sidecut!. this is a Junior ski , not race stockof any kind.. I'm sure he'll be fine on it (I don't believe they make any 130cm Adult Sl12's anyway) as long as the base bevel and side edge bevel is good.

 

A 2 or 3 degree side edge will be fine. Probably not really riding rails cleanly in a race course at that age anyway.

post #26 of 28
Looking at the picture, and reading the descriptions, and studying the Atomic offerings in their catalogues I'm going to suggest that this is the ski we're talking about:

'09 Atomic SL12 jr    A085026 | 130 cm | 98 - 63 - 88mm | r = 10m

Which is a junior race ski. It may not be FIS "race stock", but it is built to be the top racing model in the junior line (compared to Race 10, Race 8 etc.).

The GS12.1 jr ski in the same length has r = 14m so we can't really call the SL12 a multidiscipline ski. However, its a comfortable radius for both SL and GS for younger skiers. A good course of action may be to let him ski this for both disciplines until he grows out of it for GS and then get a dedicated GS ski - he'll still have the SL12 for a couple more seasons of slalom training after that.

My, admittedly limited, experience of Atomic jr race skis is that they come with pretty flat bases and good 1/3 edges so chances are he'll be good to go without a grind.

As a general principle I'd treat jr. skis the same as adult ones - if in doubt get a grind so you know you have flat bases, good structure and edge angles you can rely on. With some diamond stones, maybe a 2nd cut file and an appropriate edge guide you'll be good for the whole season. Consider getting everything trued up again before each new season.
post #27 of 28
Thread Starter 
Quote:
Originally Posted by Squawker View Post

Looking at the picture, and reading the descriptions, and studying the Atomic offerings in their catalogues I'm going to suggest that this is the ski we're talking about:

'09 Atomic SL12 jr    A085026 | 130 cm | 98 - 63 - 88mm | r = 10m

Which is a junior race ski. It may not be FIS "race stock", but it is built to be the top racing model in the junior line (compared to Race 10, Race 8 etc.).
Well I finally got the skis back tonight. What a fiasco at the store...

Squawker's comments above are exactly what the ski says other than the tip which says 105. I just ran a scraper with tape over it down the bases and backlit it. They look flat to me so I'll leave it alone for right now. We'll see what he thinks Saturday.

My mistake on two items - I said they were an '08 ski. They were left over from last year - which makes them on '09. And I said they have a GS sidecut - but that's what the race coach in the store said as I was concerned he shouldn't have a SL ski yet and a GS ski would be more fitting. They are a 10M ski which he pointed out is the same as the 120 Rossis he was on last year. The Rossis were definitely a kid's ski - no airs about being a race ski. The Atomics do have a narrower waist so I think that should make it even easier for him to carve them.
post #28 of 28
I give up!
 
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Tuning, Maintenance and Repairs