The update is still in progress.  I had to revert to the old version again while some details are fixed.  there may be a few Maintenance Mode periods the next few late nights while things get tweaked.

Thanks for your patience,
Jim

Marc

This is primarily an English language board. I used Google translate.

Thanks! The JW pictures I looked at are on the JW website:

https://www.johnwilsonskates.com/products

I am not an expert! Not at skating, and not at shop work. I have given up for now on making my own blades.

I have found a lot of contradictory information and am trying to make sense of it.

Some of the best (English language) videos are at

Scarlet Skater:
  https://scarletskater.wordpress.com/2017/06/01/choosing-figure-skating-blades
  https://scarletskater.wordpress.com/2017/06/02/blade-profiles

Aimée Ricca's Youtube site, such as
  https://www.youtube.com/watch?v=SCTmQDZMyN0&list=PLhIvo-BmGcaU_Oz4eM2T7YCAZWDKkch4I
  https://www.youtube.com/watch?v=Y6CdHJyHdQg&list=PLhIvo-BmGcaU_Oz4eM2T7YCAZWDKkch4I&index=3
  https://www.youtube.com/watch?v=_Xx9Z-7NM4Y&list=PLhIvo-BmGcaU_Oz4eM2T7YCAZWDKkch4I&index=3&pp=iAQB

I also like at Everglides:
  https://everglides.co.uk/
  https://www.youtube.com/@everglidesskatingspecialis495
  https://www.youtube.com/watch?app=desktop&v=PjRFziQKKrA

And Coach Julia:
  https://www.youtube.com/watch?v=h516z1Tneuk
  https://www.youtube.com/watch?v=pEAnb4kRrFU

And
  https://www.danielyeow.com/2011/inline-to-ice-1
makes it clear that my information on speed skating rockers is wrong or out of date.

SP Teri's website says their boots are designed to balance in the center, not the ball of the foot.

Aimée Ricca's videos claim blades should be 1/2 inch to 1/8 shorter than the boot - mine may be too long.

A skate tech (not sure how expert, or if he is correct) recently told me that long figure skate blade sizes use the same rocker radii as short ones, but the lengths of the segments using each radius changes. He didn't know exactly how.

Requête,
Tu pourrais m'envoyer un lien pour les photos des lames JW s'il te plaît.
Car j'ai acheté une lame d'occasion et je voudrais comparer avec la courbe du neuf.
JW parabolic ( je pense que c'est vieux mais ma fille voulait essayer).
Je suis toujours avec attention toute vos discussions et entreprendre de construire sa propre lame est un vrai challenge et je te souhaite d'y arriver....
Merci et au plaisir de lire tout vos message ici qui sont super instructif.

Way overdue - my apologies.

tstop4me, I wasn't saying there is little or no difference. I do know very small changes make a huge difference. Differences I can barely see have made a huge difference in how i skate.

I'm just trying to figure out the basic geometry and intuitive physics of blades.

This was originally inspired by the idea of making my own blades for myself - though I'm realizing that's a lot more complicated and expensive than I thought, in terms of tools and even the raw materials.

But then I just got curious. Why aren't short blades just a miniaturized version of long blades? But if that were true, the toepicks woudn't be the same size (which as we were told in another forum, they do seem to be), and a 12 inch (mounting plate length) blade would have twice the rocker radii of a 6 inch blade (just an example; I know most blades don't cover that large a range) - which we know they don't.

I don't understand why they aren't completely scaled like that. The angles of roll would be the same. The places where weight is borne on the foot would be the same. Etc.

One skate tech, who sharpened blades for a major skate boot brand, told me he thought the shapes of the front half of blades of a given model were identical, regardless of scale. But for reasons I mentioned, that makes no sense - why would a little foot bear the weight of jumping in the middle of the foot, while a long foot would bear it in the toes?

There are blade pictures online. E.g., MK, JW and Paramount have pictures of all their blade models, in almost a flat projection - close enough that I could perhaps calculate radii and transition points, if I knew the scale. I downloaded them all to play with. The image formats contain a scale, but they are presumably photographs not scans (because you can also see the mounting plates), so the scales might not reflect reality, as much as the photographers original intended display size. (I thought of using the published main rocker radii to scale the sizes, though I'm not sure the image resolution is fine enough to accurately calculate a main rocker length). Ultima's pictures are in a weird perspective, but other pictures of Ultima blades are available online. But - for the most part, none of these label the size of the blade, and they only display one size.

Tstop, that's interesting.  I felt faster in that way on 7' Coronation Aces in a test try vs my 8' Pattern 99s. 

I stick by my belief that blades actually don't make much of a difference.  (Except the bleeping rentals.)  People hate on Aspire XPs, but I found them adequate and accomplished a lot on those.  CA felt really nice, but at the end of the day I could do the same things on the P99s.  Same for Phantoms.  Granted I do single jumps, so perhaps I'm missing the stability feature or not, but most people seem to complain or talk about spins and blades and not jumps.  I really haven't felt that much difference on any of the blades.  Like, it's nice on the P99s or CA, but if I had to use Aspire XPs it would be fine (and that is with questionable sharpenings on a bench grinder for close to a year.)  Aspires maybe don't glide as well, but spinning actually worked well.  Basically it seems nice to have better blades, but it really, really doesn't matter much.  IMO

Except those rental blades.  No one with figure skating goals should use them ever.   

Quote from: Query on October 22, 2024, 01:54:10 PM

I think you are implying there are psychological factors too.

My point though was that a skate tech would probably have to take a measurement to see the difference. Given the minimal training a lot of them have, and the pressure to sharpen as many blades/hour as they can, I wouldn't expect most of them to notice the difference.

Nope, I'm not implying any psychological factors.  My point is you determine functionally how small an increment is significant; and then you settle on the proper tools and procedures for measurement.  You seem to be approaching it the other way:  The visual difference between images is hardly perceptible, so how could it make a difference?

When I switched from a 7' to an 8' radius main rocker, the difference was immediately apparent to me.  With a 7' rocker, I always struggled to complete the circles on my Figure-8s; but when I switched to an 8' rocker, the glide was so much better that I had no problem running out of steam.  And part of my warm-up exercises involves skating backwards the entire length of the ice.  The first time out on an 8' rocker, I was zipping so unaccustomedly fast that I crashed into the boards behind the red line; something which I had never done with a 7' rocker.

I started a discussion on another board about how (new) blade shapes vary with length. So far one person has offered to measure their old (used) blades, but no one has responded who actually knows.

Does anyone here know?

Is there any variation of rocker radius, length of rocker sections, or positions, as length changes, within a given brand and model?

If there isn't, then, for example, on many blades, the point where you are on the rockered section, when the toepick starts to touch (which some coaches teach is where you do turns, and where many coaches teach you should do a scratch spin) would be in the middle of a very short foot, but maybe in the toes of a very long foot. (That's assuming a specific convention for full custom boots in which the front of blade mounting plate is at the front of the outsole, which is in turn the length of a radial projection of the skater's foot. I.E., the front of the mounting plate radially projects to the front of your toes too.) Yet many coaches tell their students to use the same model blades they use, even if their feet aren't the same size.

So, is there some type of scaling, and if so, exactly what?

I haven't been able to find a source on this.

It would be wonderful if someone here with full access to a pro shop could scan (at as high a resolution as possible) a short and long new unsharpened blade of the same model, and place the images somewhere (right now skatingforums doesn't seem able to attach images any more - I couldn't even attach the small one I linked to in my recent thread on 7 & 8' rockers). 

A lot of people claim it is harder to center spins, but easier to land jumps (for stability), on 8 foot rockers. Including some on this board.

I don't know how well controlled any experiments they ran are.

I.E., other blade shape factors differ too, blade to blade. As perhaps they should? All other things being equal, an 8' rocker would otherwise lift the toepick less off the ice.

I think you are implying there are psychological factors too.

My point though was that a skate tech would probably have to take a measurement to see the difference. Given the minimal training a lot of them have, and the pressure to sharpen as many blades/hour as they can, I wouldn't expect most of them to notice the difference.

The more pertinent question is:  "Can a skater feel the difference between an 8' vs a 7' radius main rocker?"  Similar to previous discussions on:  "Can a skater feel the difference between a 3/8" vs a 7/16" vs a 1/2" radius of hollow?"  This is the criterion that I refer to as "the proof of the pudding".