They have stopped making them.

ISE blades were more or less clones of much more expensive blades from companies like MK and JW.

E.g., the ISE Sabre Dance blade - the closest that was available comparable to the MK Dance (and like it was a Chrome plated high carbon steel blade, with slimline cut at the bottom, but with somewhat less aggressive toepicks, same 7' main rocker but somewhat different spin rocker) is out of stock at both Jerrry's skating world, whose brand name ISE is (and might have been the manufacturer), and its retailers. 

They were available a few weeks ago for $75, which was a great price. I waited too long to get them...

https://figure8.ca/shop/index.php?route=product/product&product_id=2123 has a few left, but NOT in my 9 3/4" size. I'd consider 9 1/2", because my desired length is borderline, but they don't  have those either.

Jerry's still has a lot of Sterling blades in stock. So do other retailers like https://figure8.ca and https://figureskatingstore.com.

But they aren't slimline dance blades. They are stainless steel.

I didn't check on their other blades.

One of those two retailers told me that Jerry's is considering getting an alternate manufacturer.

There actually are other conditions in which the forward rocker segment might affect skating.

I have sometimes skated on (shallow artificial) outdoor ice rinks in which the ice was melting on top, or was actually melted. Sometimes the entire blade, and maybe some of the boot, was underwater. (Obviously you would not want to do this on a natural pond that was deep enough to be unsafe if you broke through.)

Under those conditions, maybe the streamlining of the blade would be affected by that part of its shape.

I didn't love skating under those conditions. But some kids enjoyed splashing other skaters with cold water.  I suppose the entire shape of the blade might also affect how good the blade is at splashing. Though - moves resembling hockey stops arguably work best, so I don't know if it would make much difference.

A few more thoughts:
1. It would be fairly easy to modify DrawBlades.f90 to extend the cuts, and compensate for line width so one could cut on the outside of the line, because the runner is a simple convex shape.
2. Where a long radius arc and a short radius arc meet, one would cut and extend the long radius arc first, then cut the short radius arc.
3. Just as a circle cutting jig would help make much cleaner rocker arc cuts, a strip cutting jig would help make cleaner straight line straight line cuts. I already have one.
4. One could make one's own circle cutting jig as a thin board of sufficient length, with an attached metal strip that fits into the same slot as the strip cutting jig, and nails at the right radii. The nails would fit into boards, mounted onto separate tables at the same height as the board and table the steel was clamped to.
5. Hardening 440C steel sounds complicated. Hard to make sure it doesn't warp? Temperature by color good enough? 6. A propane torch is more than hot enough - have to make sure the steel doesn't melt. On the other hand, if one actually austentizes it, it would be non-magnetic, so steel filings wouldn't stick during sharpening.
7. Sheet/bar 440C steel is listed at about Rockwell hardness 20. The main body would presumably stay that hardness. Is that about right?
8. Maybe Jerry's ISE blades are cheap enough to use instead of all this effort... Like I said, I'm getting discouraged.

I would need about 1/8" (11 guage) 440C stainless steel for the final runners. About $90. Early prototypes could use cheaper steel.

I would need a heavy duty (over 600 watt) jig saw, and cutting oil. My best saw is borderline.

A $40 circular cutting jig would make smoother arc cuts than I could. But wouldn't do 18" - 8 foot radius. I could maybe tape on a long flat extension piece. The resulting offset would make the arc imperfect. Wouldn't matter much for 7 or 8' radius arc. Might matter for an 18"-27" radii segment.

Could use the radial lines my software can generate to get the direction of the center of the arc right.

Extruded aluminum channels (with a right angle bend) might be the simplest right angle brackets that could be bolted onto the mounting plate.

I could add free software to generate DXF files for CAD/CAM. (For that matter, I could have used free Postscript generating software, but I didn't know it was available.) And maybe FreeCAD could generate the CAM files to control a CNC guided milling machine, which could both mill (to cut) and drill. But CNC milling machines are expensive and apparently easy to break. So maybe not worth it.

A milling machine might be needed to thin the runner at the bottom.

I'm getting discouraged.

I have somewhat updated my DrawBlade program and related stuff. Some of it has been renamed or move. The new version is at

http://mgrunes.com/boots/DrawBlade

Note that DrawBlade.txt and DrawBlade.ps are much more readable. And my particular terminology (which tstop4me insists is not the standard he likes) that the program uses is explained at http://mgrunes.com/boots/DrawBlade/DrawBlade_labeled.png - The image can easily be viewed with a web browser. Most web browsers can use the mouse wheel to zoom in and out to see small text.

BTW, I know many people think Fortran is out of date (and to some extent it has evolved to meet a specialized market, supercomputing using massively parallel processors like nVideo graphics chips, where it is still by a small margin the most common language - though this program doesn't fit that criteria), and it is possible you have never heard of it, but Fortran compilers are available for free, such as "gfortran", which can be loaded in Cygwin and Linux.

Yes, MK and JW blades are in about the same price range, especially since the two companies have merged into HD Sports.

Both are incredibly expensive. I admit MK blades used to be more expensive - but they used to say that at the highest competition levels, most skaters who won medals used MK blades. (Maybe due to marketing campaigns in which MK provided free blades to some high level skaters and coaches, and a few others? But now some JW blades are provided that way too.)

Regardless, it makes sense to add extra fancy features, which may or may not be fully understood by customers that buy them, that make people think the cost of these blades is justified. (Or maybe I just don't appreciate how hard such blades are to make?) Maybe it's like the extremely elaborate curved body shapes on modern cars, which don't have an obvious useful function.

I'm not making a distinction between the non-skating zones of 2 and 3 rocker blades. The manufacturers are. In particular, the entire "spin rocker" section of 2 rocker blades has the same curvature, even the part Broadbent calls the "non-skating zone" because it usually can't touch the ice much if at all. Whereas JW gives that segment a different curvature.

My question was if & how much that matters.

Which you aren't trying to answer, because you are hung up on terminology that I don't really care about.

* So now, it appears you are making a distinction between the non-skating zone of a 3-rocker blade vs. a 2-rocker blade?  My reaction is, "Huh?"

* I'd like to point out that all these complications you've presented result from your definition of a sweet spot and that these complications vanish under a different definition (e.g., the tangent point; see below).

* Again, "the proof of the pudding is in the eating."  Let's hear from the professional coaches and techs on this forum.  How many coaches distinguish between front and rear sweet spots for 3-rocker blades and provide different instructions vs. 2-rocker blades with a single sweet spot?  And how many techs trim/do not trim dragpicks based on whether the blade has 3 rockers vs. 2 rockers?

* Sid Broadbent has a "wellness gauge" for determining when the dragpick should be trimmed (http://www.iceskateology.com/Skateology/Blade_Wellness_Gauge.html).  PBHE has a similar gauge.  These are geared towards HD Sports (Wilson and MK) spin rocker profiles.  Paramount adheres to these profiles, but other companies (such as Ultima and Eclipse) do not.  These gauges do not distinguish between 3-rocker and 2-rocker blades, because they do not depend on "points at which the radius of curvature changes".  They depend on two points:  the tip of the dragpick and the tangent point along the spin rocker [if the blade is oriented vertical to a horizontal reference plane (as if you were skating in a straight line along a sheet of ice), and if you rock the blade forward such that the dragpick just touches the horizontal reference plane, the tangent point is the point along the spin rocker that also touches the horizontal reference plane].  Note: tangent point refers to an idealized geometry; in an actual scenario, there will be a tangent region.

* As I've written before, in the absence of a standards authority (or authorities) that sets definitions, it's critical that posters define their terms, maintain consistency in those definitions, and follow through the logical consequences (basically, do they make sense).

*

Quote from: Query on October 05, 2024, 10:28:00 PM
I'm wondering if this is like that. That the presence of the 3rd rocker segment has virtually no effect on skating, once you have removed some metal by sharpening (or by skating a lot). But it helps "justify" the high cost of those blades.

<<Emphasis added>>  Care to provide data to support your contention that 3-rocker blades cost more than 2-rocker blades (following your terminology}?  In the Wilson line, the Gold Seal (2-rocker) costs a lot more than the P99 (3-rocker).  Now this is not a fair comparison, because the Gold Seal has concave side honing and a longitudinally tapered thickness profile, which the P99 does not.  These features add to cost.  But look at the Paramount versions.  The Paramount Gold Seal version does not have concave side honing and tapered thickness.  Paramount has multiple grades of their blades.  At their highest grade, the Gold Seal costs more than the P99.  At their other grades (for which there are comparable models), the prices are the same.  And if you compare the Wilson Coronation Ace (3-rocker) to the MK Pro (2-rocker), the prices are the same. 

It's more complicated than that. Many people call the entire "spin rocker" a "sweet spot". Saying that you should try to spin on the part of the blade somewhere on that definition of sweet spot.

But for a triple rocker blade, you can't spin on the front spin rocker section - i.e., by that definition, the entire "front sweet spot".

AFAICT, for all intents and purposes, except possibly when jumping, the front spin rocker section doesn't exist. And even for jumping, it's usefulness is unclear - perhaps it would be easier to vault over the toe pick if the front spin rocker section was a straight line, more like pole vaulting?

Bill_S said that he took measurements and found that side honing (e.g., parabolic blades) doesn't exist at the level that touches the ice. That it's main effect might be to remove a few grams of weight. I think he more or less seemed to feel that it was merely a marketing ploy a blade company could use to justify the high costs of their blades, but was pointless.

I'm wondering if this is like that. That the presence of the 3rd rocker segment has virtually no effect on skating, once you have removed some metal by sharpening (or by skating a lot). But it helps "justify" the high cost of those blades.

And by the way there are other terminology problems in figure skating. E.g., to many people "rocker" refers not to the curvature radius, but to the single point along the length I call the "sweet spot". Quite a lot of skaters and coaches use that terminology. And you see it a lot on Youtube, and in other videos, that teach figure skating elements.

And others use "rocker" to mean "rocker profile" - the whole shape of the bottom of the blade.

I was really hoping to get some comments on the issue I am talking about - why that spot - which you might prefer me to refer to as "the point along the length of the blade where the rocker profile curvature changes" (so many words! ) - exists, and whether it makes any sense, or is just a marketing ploy.

I admit a lot of people do buy triple rocker blades. But a lot of people buy blades with various forms of side honing too. (And people have told me they feel parabolic blades are much better for landing jumps, in spite of what Bill_s said.) What people buy doesn't always mean they have tested every aspect of what they buy.

The issue is not the terminology per se.  As I discussed before, the issue is what happens when you communicate with others, e.g., coaches and techs.  According to you, there are fundamental differences in the sweet spot(s) of e.g. a Coronation Ace/P99 (what you call a triple rocker blade with two sweet spots) and a MK Pro/Gold Seal (what you call a double rocker blade with one sweet spot).

So if a coach is teaching a scratch spin, and is giving instructions on finding the sweet spot, she now needs to distinguish between blades with one sweet spot and blades with two (or more) sweet spots, including whether or not the drag pick touches the ice depending on the number of sweet spots, and, for blades with two sweet spots, whether she's talking about the front sweet spot or rear sweet spot.

And if a tech needs to decide whether, after a sufficient number of sharpenings, the drag pick needs to be trimmed to maintain the position of the sweet spot, he now needs to distinguish between blades with one sweet spot [no trimming needed] and blades with two (or more) sweet spots [trimming needed].

Well, we have professional coaches and techs on this forum.  I'd like to hear whether any coaches provide different instructions and whether any techs follow different sharpening procedures according to whether the blade has one sweet spot or more than one sweet spot, as you have defined it.