Edge and wax without base grind....Question

[François Pugh]

Yes, filing the base angle will take some material off the base. You will end up with what's called by some "a long bevel". Not much of a problem unless it's too long. Then you need a base grind. Your skis are usually on edge anyway (or should be).

People who say you should never touch the base bevel don't live and ski where I do, have way too much money to spend on base grinds and shop tunes, or just don't ski in such a fashion that then need sharp edges. I don't touch the base edge very often, but sometimes I do.

Also note: ski material, other than the metal edge is great at gumming up your stones.

 

[KingGrump]

my shop (and Ive asked often) tells me they tune a 1-2* side as standard unless one wants less/more. Id assume they have a machine set up for this but did not ask. But honestly unless the person in charge really dos understand and care how can you really know what you get.

For a 1-2 edge angle you need a side at 3 from flat in order to compensate for the 1 degree base. How can I know if whatever they do is not overlooking that fact and what I end up with is actually a 1-1. I honestly don't but I am going to ask when I go pick them up cause its has me curious now.

A 1/3 will give an 1˚ base edge angle relative to the ptex base. The 3 actually stands for a 3˚ less than a square 90˚ side edge angle. So a 3 is actually 87˚. That angle is relative to the ptex base rather than the base edge angle. A 1/3 tune will get you an included angle of 88˚. A 1/2 tune will get you a included angle of 89˚. Just remember everything is registered off the ptex base.

Some shop say the do base bevel. Some actually do base bevel. Ask to see how they bevel the base. I have seen skis that came back from the shop with a so called 1˚ base bevel that had spring structure on the steel base edge.

When it comes to tuning shops. Trust no one.
If you can't see or measure it. Assume it didn't happen.
Talk is cheap.
A nod of the head is cheaper.

How do you measure the bevel?
@SlideWright has a thread on that.

 

[Burton]

I just took a pair of skis into a very, very good shop that specializes in race tunes. Brought in an essentially new pair of Dynastar FIS slaloms (3 days on snow) that I had spent a lot of time on working the sidewalls and side edges, but I never touched the bases other than to confirm the base edge angle was greater than .5 a degree (by using my .5 base bevel and a diamond stone that never engaged with the edge). In tuning the side edges, it was really interesting to see how wonky these skis were straight out of the factory. I mean, they were serviceable, but being precise about applying a 3 degree side edge angle really showed that these skis were made with the assumption that they would have a lot of work done before use.

The shop owner looked at the skis and, knowing the brand, said "factory bases? so a 2 degree base edge angle?" That really surprised me, but we measured them, and sure enough the base angle was roughly 2+ degrees, with some variance along the length and from one edge to the other. In other words, pretty lousy for these skis' intended use. I was planning of having them base ground regardless, but this really drove home that at least for a ski that needs to carve very well on ice, a factory tune should not be relied on.

 

[TahoeCharlie]

I just took a pair of skis into a very, very good shop that specializes in race tunes. Brought in an essentially new pair of Dynastar FIS slaloms (3 days on snow) that I had spent a lot of time on working the sidewalls and side edges, but I never touched the bases other than to confirm the base edge angle was greater than .5 a degree (by using my .5 base bevel and a diamond stone that never engaged with the edge). In tuning the side edges, it was really interesting to see how wonky these skis were straight out of the factory. I mean, they were serviceable, but being precise about applying a 3 degree side edge angle really showed that these skis were made with the assumption that they would have a lot of work done before use.

The shop owner looked at the skis and, knowing the brand, said "factory bases? so a 2 degree base edge angle?" That really surprised me, but we measured them, and sure enough the base angle was roughly 2+ degrees, with some variance along the length and from one edge to the other. In other words, pretty lousy for these skis' intended use. I was planning of having them base ground regardless, but this really drove home that at least for a ski that needs to carve very well on ice, a factory tune should not be relied on.

This is pretty weird as "The Piste Office" Manufacturer's base/edge angle list's show NO ONE ships with more than a 1* base angle. Specifically, it lists "Dynastar, all models as 1,1". Given that this is a FIS Slalom ski, it is even stranger as I would guess that FIS Slalom skis are usually skied at around a .5* base angle. So a pretty significant base grind is going to be required to go from a 2* to a .5* base, right?

 

[Burton]

This is pretty weird as "The Piste Office" Manufacturer's base/edge angle list's show NO ONE ships with more than a 1* base angle. Specifically, it lists "Dynastar, all models as 1,1". Given that this is a FIS Slalom ski, it is even stranger as I would guess that FIS Slalom skis are usually skied at around a .5* base angle. So a pretty significant base grind is going to be required to go from a 2* to a .5* base, right?

Well, having recently hand tuned several brand new skis from different manufacturers, I'd say that most ski companies have listed specs, but what comes out of the end of the manufacturing line can vary quite a lot. Maybe some companies (Stockli?) do a better job than others. And you're right, the goal for these would be .5 of a degree, but I don't think much base has to be removed to get there. Honestly, removing a degree and half across the width of a ski edge is a pretty small amount of material.

 

[Goose]

A 1/3 will give an 1˚ base edge angle relative to the ptex base. The 3 actually stands for a 3˚ less than a square 90˚ side edge angle. So a 3 is actually 87˚. That angle is relative to the ptex base rather than the base edge angle. A 1/3 tune will get you an included angle of 88˚. A 1/2 tune will get you a included angle of 89˚. Just remember everything is registered off the ptex base.

Some shop say the do base bevel. Some actually do base bevel. Ask to see how they bevel the base. I have seen skis that came back from the shop with a so called 1˚ base bevel that had spring structure on the steel base edge.

When it comes to tuning shops. Trust no one.
If you can't see or measure it. Assume it didn't happen.
Talk is cheap.
A nod of the head is cheaper.

How do you measure the bevel?
@SlideWright has a thread on that.

Thanks. For some reason I was remembering wrong and that the side angle was listed as per its relevance to the base angle and not the ski ptex base of flat. I don't know why I was thinking this way. But I do get exactly what you describe and makes perfect sense again.

The thing I didn't know was that a basic edge&wax is normally only "edged" on the side unless specific issue. And with that, my original question needs no answer as its not really a problem.

 

[Sibhusky]

Well, we don't know what your shop is doing. It's not like they all agree on the services with each other. In fact, the only way to know what's being done to your skis is if you do it yourself. Second choice, watch them do it and ask a ton of questions. You could write detailed instructions and as you walk away they hand it to their buddy who does what he pleases. After a series of tunes which resulted in me "fixing" the ski, from at least three different shops, I only trust me. I'm sick of having fights with these dudes.

 

[KingGrump]

You could write detailed instructions and as you walk away they hand it to their buddy who does what he pleases.

They wouldn't do that. Would they?

Unfortunately, that is exactly what happens most of the time.

 

[Goose]

and the person changing the oil on your car may not be doing anything. I mean unless you mark and check the filter yourself you don't know if it was changed. And how do you know they put in the right oil anyway? I mean most any service we may pay for is always at risk. What can ya do? You either have to do it all yourself or re-check everything or accept it all for what it is.

With that said I am always on the cautious side of anything I need to get done by others. Especially being a mechanical guy and generally good with my hands. I cannot believe the laziness, non caring, incompetent work people actually perform as so called professionals. Some the stuff people fix, service, etc... can be done so badly. But again what can you do? I trust the guys at the shop I use for my skis. They are knowledgeable good guys and are helpful. There seems to be a genuine willingness to care about you and your equipment and very easy to talk to about any of it. Im pretty good in their hands I feel.

 

[Doug Briggs]

Doing just the edges (side AND base) will, as @François Pugh points out, end up in a long bevel and you can actually extend that bevel into the P-Tex depending what tools you are using. If you want to keep the base bevel from becoming too 'long' and setting a bevel in the P-Text, you need to remove P-Tex with a base grind.

Illustration of ski cross section, upside down

NOTE: For the sake of clarity I have removed the base sheet, core and sidewall from illustrations below.

You can get your skis sharper just doing the side edges. As you remove side edge you also move the corner of the edge in towards the base thus effectively removing the likely slightly rounded portion of the base edge. Not all of it necessarily, but enough to create a more distinct and angular transition from base to side edge.

Illustration of a rounded edge

Illustration of a rounded edge after side file/stone only, partial round edge removal

Illustration of rounded edge after more aggressive side file/stone only; complete round edge removal

If you just polish your base edge to remove the outies and smooth out some of the roughness you don't remove much material. If you only use medium to fine diamond stones on both edges, you remove burrs and freshen the corner of the edge. Depending on how sharp you need them, just a fine stone can do the trick. If you have significant damage or need really sharp for ice, you'll end up taking of more material. Until you use a file or a very coarse diamond stone, you aren't removing that much material from the edges and won't develop the 'long bevel'.

Illustration of a 'long bevel'

Changing from a 2* to a 0.5* requires a lot of P-Tex removal even if the bases are flat and the base edge is flush with the base where they meet. You have to lower the P-Tex side of the base edge sufficiently that you can form the 0.5* bevel. That means repeatedly trying to set the base bevel to 0.5* interspersed with base grinds. The reason to remove base, then edge, then base then edge is to protect the stone from excessive contact with the edge which shortens the life of the dressing on the stone and puts structure into the edge. In the illustration below all of the material illustrated in gray needs to be removed to permit the base bevel to go from 1* to 0.5* along with the metal edge between the 1* and 0.5* lines.

Illustration of edge and P-Tex required to be removed to change base edge bevel

Base grinds only need to remove a lot of material if you are changing a base bevel from a higher number to a lower one or your bases are convex. In either case you'll end up with a flat base that is flush with the inside of the base edge. I've mentioned elsewhere that I do a base grind quite frequently on my skis yet the base grinds don't end up being the reason the skis are retired.

What this all boils down to is that you have to visualize the desired results of the work done and determine whether you can deal with a long bevel or not and how sharp you need your edges. Toss in dealing with innies (missing edge material), rounded edges and convex bases. All said, it is a complex scenario to get every ski into the desired condition. You need to look at the base and edges after each pass of a tool or a machine process to evaluate if you have taken enough off for the desired results.

 

[CalG]

What possible negative aspects could be associated with a "long base bevel"? That is, a base bevel that includes the P-tex base material.

I can not think of a single one. Metal edges have been getting "thinner" with the passing years as methods and materials have improved. A long bevel that overlaps the edge to P-tex interface should be in no way inferior to an edge bevel in any width metal edge. Is there some expectation that the optimal base bevel will "just fit" onto the metal edge width? To me, that is absurd, as only ONE base bevel would conform so to any metal edge material width.

Unless I'm missing something....;-)

 

[Sibhusky]

Well, essentially you're creating a convex base. It's fine for a smidge, but eventually will affect the ski's performance when flat, like on a long cattrack.

 

[CalG]

Sib

You infer that there is a difference associated to gliding surface geometry if it is shaped only in a metal edge opposed to the same geometry shaped into a combination of base material and metal edge.

I see no difference.

I have had skis that wear to a base high condition. and others to an edge high condition. Materials and environment.....

 

[Sibhusky]

The term "vs." implies only two states. It's a continuum. When you ride the skis flat and they are convex they won't be as controllable, and it'll be longer to engage the edge. I'm not a fanatic about flat bases, but at some point it becomes an issue and even Jacques, who loves the "long bevel", flattens the ski. Let's assume you only ever hit 3d snow (really?), eventually it's going to affect your side bevel as well.

 

[g-force]

html http://pisteoffice.com/index.php/1-tuning-advice/terminology.html Pisteoffice has a good explanation and so does Mr. Briggs. Many are circling. Base Bevel is all about how the ski actually feels when you ski it. Most people think their bases and base-edges are flatter than they actually measure.
At home I go for base-grind Only when the time comes... I can't get a good result without a fresh base stone-grind with a chevron or broken linear pattern. Flat... No HTT or side-edge, no wax. (Or the trusted full meal deal Real tunes are 80 bucks... ceramic finish on base and side edges.
Assume a Flat base P-tex with perhaps only 1-2 mm of file work into it. I try to avoid more than 1mm but this is hit and miss.
If a ski is too base beveled; it feel loose then will hook up too late and grab suddenly and the range of useful edging will be reduced to 'squirrely'.
If a ski is too flat for you it will hook-up too soon in the turn - before your mass is fully inside the arc. Pivoting skis when flat on Dialed boots is assumed and flat lasts only a moment in a turn compared to the time spent on edge ( and - of course - I Never Skid ).
You should be able to run your thumbnail on the 'smooth'-feeling' corner of the edge from tip tip tail; yet it should peel when scraped across the base-edge corner..
I find a .5 to .7 most useful for Sl,GS and Carvers. 1* for fats. Only round off the tip and tail that is off the running surface. As use grows, the base edge angle can only increase. Sometimes you have to trade-off side-edge and a few cms of base-edge with a file after taking a hit. For your semi-nighlty-tune-up-and-wax: Stones only or a file-pass on the side-edge... Stone the base-edge burr after the side-stone.
I find a 2*side pretty good and suspect a 3* of early wear...
I have experimented when I score a nice used pair that has a 3* side and I am looking for my usual 2*... If you want a killer side edge; tape-shim the side-guide to a bit more of an angle; then remove it and Reduce the angle to your final file-guide ... this will allow you to work on the very corner of the side edge...

 

[Doug Briggs]

What possible negative aspects could be associated with a "long base bevel"? That is, a base bevel that includes the P-tex base material.

I can not think of a single one. Metal edges have been getting "thinner" with the passing years as methods and materials have improved. A long bevel that overlaps the edge to P-tex interface should be in no way inferior to an edge bevel in any width metal edge. Is there some expectation that the optimal base bevel will "just fit" onto the metal edge width? To me, that is absurd, as only ONE base bevel would conform so to any metal edge material width.

Unless I'm missing something....;-)

I have pondered the same thing. Here are a few reasons I came up with.

I have come to the (unsubstantiated) conclusion that the longer the bevel the less responsive the base edge is to engaging the snow. Most of my (weak) justification for this comes from the way racer's skis are tuned. I don't think you'll find any long bevels on race skis as race skis are tuned for maximum performance which includes effective edge engagement.

Beveling your base means less of your base will have structure, which I think we can all agree is slow.

On hard snow you need your edges to penetrate the snow to be effective. A long bevel allows the P-Tex base to support the ski and resist snow penetration whereas on the same edge angle a regular (not long) bevel would have more pressure on (and into) the snow as the base isn't resisting penetration.

Your base and side edge bevel guide contacts the base. If you have a 1* base bevel for an inch of the ski's width and you put a 2* edge bevel guide on it that is only 1 inch wide, then you are effectively putting a 3* edge bevel on the ski with a 2* guide. Additionally, while a file will cut P-Tex, the type of files you use to set precise edge bevels aren't particularly effective at cutting P-Tex.

Stability of the ski is also a factor, particularly on hard snow. You'll have less base on the snow when on a flat ski. A 65 mm ski with a 20 mm long bevel on each edge will leave 25 mm of P-Tex to ride flat on the hard surface.

 

[CalG]

Doug

I'm thinking a "long bevel" in terms of the realistic limits of a few mm. The idea of a 20 mm long bevel seems absurd.

Or, with a bevel that "long", it would take very sophisticated measurement to discern the exact base bevel. For certainly it would be so near "flat" as to be disregarded.

 

[Doug Briggs]

I mention the 'extreme' 'long bevel' for a visual, but the reality is that many skis I see have excess P-Tex relative to the base edges from wear from use which is pretty much equivalent to the 'extreme' 'long bevel'. I don't let my skis get that bad but I don't really find an effectively rounded base a functional one.

Depending on the type of tune I do and the original condition of a ski, I might end up with a long bevel of a mm or 2 on recreational tune and I know the ski is in much better condition than when I received it as the formerly round and convex base has been reduced to a small long bevel and the edges are sharp and set to the desired bevels. Much better but not perfect. A noticeable improvement.

 

[Goose]

You go down with a base grind.

When you say you want a 2 degree edge, most shops will set the edge at 2 degrees. What the base edge has doesn't matter. If you are expecting a 1/3 that = 2 degrees, well then you need to tell them.

Unless you are racing, don't over think it.

I mentioned before, there was a misunderstanding on my part. But I got it now and again is understood.

 

[Dakine]

Running the base bevel well into the ptex is an old tuner's trick to improve glide.
Steel is slow and wax is fast.
A bevel as much as 1cm into the base will glide very well without giving up much edge grip.
It keeps the edges off the snow when flat.
It also makes them squirrely during transition.