You know, I actually have to agree with that. Daisies passed all 8 figure tests and prefers blades that would probably have me slipping all over the place. Her form is perfect and her skating always looks effortless, so it's consistent with that argument.
What I like about freshly sharpened blades is that I can get away with poor alignment on my edges and my blade will still hold the ice. When my blades are dull, I need to make sure I'm aligned perfectly over my hips whenever I do a deep edge like a spin entry, salchow takeoff or landing edge. Otherwise, I will slip off of it. I use a 1/2" ROH but my blades are side honed so I think that increases the bite on deep edges.

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"You don't have to put an age limit on your dreams." - Dara Torres, 41, after her 2nd medal at the 2008 Olympics

I don't know if Daisies uses patch blades, but if so, they use a very, very shallow hollow and the tracings show only one edge when the figures are skated properly.

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I don't want to derail the thread but would like to make a couple of comments on RoH.

Radius is only half of the equation for 'grippy-ness' - the other factor is blade width. RoH together with width create what is called "bite angle" and it is actually Bite Angle that we feel when we are skating. A wider blade with a shallower RoH will have the same 'bite' as a narrower blade with a deeper (smaller) RoH.

In terms of performance and/or skill, a blade with a smaller RoH has less tendency to slide sideways and will be less forgiving of mistakes or inaccuracies in landing, footwork, etc.

I had heard (and believed) that the deeper the RoH, the less efficient (and more work) was required in skating. When I switched from 3/8" RoH to 5/16" (a 12% change) my perception was the opposite - it was like being on ball bearings! Not only were my edges more secure (being able to hold an edge right down to the point where the boot touches the ice) but my glides were longer - seemed like much more than 12%! On the other hand, when you put your foot down, you had better be prepared to go in the direction the blade is pointing because you have no choice! (Ask my coach who watched me do a laughable splits coming down out of a spiral!)

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Dianne
(A.O.S.S.? Got it BAD! )

Oh no, not for freestyle, LOL! But she only sharpens her blades a few times a year and may even dull them down a little right after sharpening.

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"You don't have to put an age limit on your dreams." - Dara Torres, 41, after her 2nd medal at the 2008 Olympics

I remember your post about that. It WAS surprising. I wanted to ask some questions about that, but never did at the time.

I have felt a fresh sharpening to be faster than an old sharpening. Are you sure it wasn't just a shiny new edge that made the blade faster, and not the ROH change?

I'm sure you felt the extra speed, but I'm trying to narrow down the other variables that might have been at work.

Plus, a flatter rocker will be faster too (I felt that BIG TIME when I had a pair of blades ruined by a rink sharpening). When you went to the smaller ROH, I'm sure that you had to remove more metal than a touch-up sharpening. Could that have contributed?

Oh, to have rink time and research dollars available! Right now, I'd settle for just the rink time.

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Bill Schneider

Yes, you, me, and Sid Broadbent (an engineer who has studied the skate/ice interface for years)!

Then you have had the same experience! A fresh sharpening creates a sharper bite angle where before there was a radius (worn edge) created a more obtuse angle.

Since I have my own sharpening machine, I tend to touch up my blades frequently (10 to 12 hours) so I don't have that dull-to-sharp shock. When I switched radius, it DID take a lot of grinding but they weren't anywhere near dull.

So who is going to fund our Radius of Hollow research project?

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Dianne
(A.O.S.S.? Got it BAD! )

I have his book, which I picked up at Klingbeils with Don's approval to permanently remove it. DH copied it, but I have yet to remember to return it.

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Hey party people! Thank you, doubletoe, for the compliment.

Yes, I did pass my 8th figure test on patch blades, sharpened at 1-1/2. But my freestyle blades are 5/8, and I only get them done maybe three times a year ... and that's pushing it. LOL. Twice a year is more like it. And when I do have them sharpened, I have the person sharpening them use a stone to "take the bite out of them" too!

I don't know if there is any correlation between skating quality and degree of hollow, I just know I hate sharp blades. Even as a kid I rarely got them sharpened. I must say, the biggest advantage is that my current blades are almost seven years old and they still have a lot of sharpenings left in them! (Unfortunately, the boots are also seven years old and are on their last legs!)

The pie analogy got me thinking (and hungry)....

Figure sharpening - basically dull & flat = nibble out of a cookie
5/8 or 10/16 Recreational sharpening- sometimes called combination= bigger nibble
1/2" or 8/16 = freeskate sharpening = small bite
7/16 = sharper freeskate = bigger bite
3/8 or 6/16 = dance sharpening = biggest bite

The bigger the bite out of the flat blade - the deeper the hollow on the sharpening and the higher the edges are on the inside of the blade, which means deeper edges. The shallower the bite out of the blade - the lower the hollow is to the ice and the smaller the edge, which means you will slip more without a great deal of lean etc.

Perhaps it varies from skater to skater. Personally, I find that when my blades are getting too dull, I have trouble spinning (especially camel spins and flying camels), the take-offs of jumps like my double sal get worse, and I have trouble really holding on to my edges or taking deep edges to begin with on my [Gold] dances.

Maybe your patch blades are flatter...and that will make a big difference with the hollow.

Everyone likes a different "bite" to their blade, and it also depends on the weight of the skater and their style. My husband, who is just above a beginner, has the same roh as I do. My daughter, who was working on a double loop and such before she left home, has been skating on a 1/2" roh.

go figure

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Skate@Delaware
Ah, show skating!!! I do it for the glitter!

The reason I used the "pie" analogy was to simplify things at first. But being that most who are online here are 12 and older, I moved on without the pie for the rest of the fractions. I knew somehow that those who were a bit confused with the differences of 5/8 and 7/16 would catch on once they were reminded that all they had to do was to get a common denominator for whatever ROHs they were comparing.

I've also used pie to teach note values. For example a whole note (circle) would be a whole pie or 1/1 or in music 4/4. A quarter note (filled in circle with a stem attached) would be a quarter of a pie or ¼.

By the way, what flavour is your pie? I love cherry, strawberry, apple, apple & rhubarb and blueberry pies. But I have to be careful that they aren't made with artificial colour, artificial flavours or sweeteners that aren't sugar because of my alergies.

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"It's not age that determines but the heart." "Skating is not just a sport for the young but it's a passion for the soul of the young at heart." Brigitte Laskowski

I am a nomadic adult skater who is a member of Windsor FSC (Skate Windsor) WOS SC again since Sept. 1st, 2008.

http://eastcastlemusic.tripod.com

Singerskates Sports Music Editing

I think a lot of other variables must go into what sharpening works best for each skater, including the skater's ability; what the ice is like; and what kind of sharpening the skater learned with.

I find that I can spin better on duller blades, but that I can jump and ice dance better with sharper blades. Our rinks are all bitterly cold with very hard ice. I much prefer the sharper blades; however, most of the other adult skaters here tell me that it's harder for them to skate on newly-sharpened blades.

(And I can just barely do a two-foot spin in my hockey skates--sharpening is probably about the same, but a much narrower blade and different rocker.)

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You miss 100% of the shots you never take.--Wayne Gretzky

There's a country song in there somewhere...

That would make a great research paper. I wonder if the University of Delaware has done anything like this in their Sports Science program?

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I get the "pie" analogy...I am a home school mom/teacher as well, and am well versed in the "pie" analogy thingie! I am also getting really good at learning (read: re-learning) math along with my dd! I was making a joke about just "pie" in general...of which I LOVE raisin pie..mmmmmm!...after that, I guess any berry will do...*licks lips just thinking about it...*

It definitely does help to reduce all fractions to the common denominator to decide which it the largest/smallest.

LMAO!!!!

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BuggieMom
><>
Some people are like a Slinky...not really good for anything,
but you still can't help but smile when you shove them down the stairs....

...and the name of the group would be "Rusty Blades and the Professors"


One thing no one has mentioned yet is to use decimal equivalents for the fractions. In other words,

3/8" ROH = .375"
7/16 = .4375
1/2 = .5
5/8 = .625

Or would that be confusing too?

I know I'd prefer it though.

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Bill Schneider

Or Engineers on the Edge

Personally I usually work in decimals for mechanical stuff. Fractions get WAY too confusing when working to tight tolerances. Quickly, in your head, solve:

1" + 3/128 + 5/64 - 3/32 = ?

See what I mean

And if that's not confusing enough, try reading a Vernier caliper that is calibrated in fractions!!!

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Dianne
(A.O.S.S.? Got it BAD! )

Or you could just spend the extra $2 and get one with a digital readout...

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You miss 100% of the shots you never take.--Wayne Gretzky

That's what I have Hon, all dial instruments now!

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Dianne
(A.O.S.S.? Got it BAD! )

I saved the $2 and still use vernier calipers - decimal inches and millimeters. Trouble is that my eyes aren't what they used to be.

At least with the $2 I saved, I can put that toward a skate sharpening.

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Bill Schneider

Or reading glasses!

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Dianne
(A.O.S.S.? Got it BAD! )

Wish you were around at some of my college parties! We could have used some wit like that in engineering school.

Since you are an engineer and prefer numbers over vague and various descriptions, but are also sensitive to the non-engineers, why not create a series of sharpenings that use decimal inches in 0.05 increments? That's roughly a 1/16th.

The series could be:

.5 - average to light freestyle or recreational grind (exactly = 1/2")
.45 - general freestyle (roughly equivalent to 7/16")
.40 - for experienced skaters who love a deep bite (roughly = 3/8")
.35 - for semi-lunatic skaters who drag their boot edges in turns or for thinner dance blades, etc. (sharper than 3/8")

You might even pick and choose from these to avoid so many different grindstone dressings.

This avoids the messy four-digit decimals, and customers can remember it easier. It provides precision in discussion about edges that any engineer could appreciate.

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Bill Schneider

Better than that ..... I'll flip all my skaters out and go METRIC - I'll tell them it is the ISU standard:

13 mm - recreational
11 mm - freestyle
9 mm - elite freestyle
7 mm - super skaters (like me! LOL!)

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Dianne
(A.O.S.S.? Got it BAD! )

Do Canadians freak out over metric? I thought that was a US thing.

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-Jessi
What I need is a montage...
Visit my skating journal or my Youtube videos (updated with 2 new videos Sept 26, 2009)

I think all poor skaters would flip out over metric. We might all be taught metric at school, but when you have someone tell you that your blades take a 4/8 or 8/16 or 1/2" sharpening that's what you remember. To be told you want something different will freak anyone out, Canadian or European.