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Author Topic: How blade hollow, rocker, side honing, etc. affect skating?  (Read 6523 times)

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Offline Query

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How blade hollow, rocker, side honing, etc. affect skating?
« on: December 17, 2010, 09:38:18 AM »
[previously cross-posted to Yahoo competitive and ice dance groups]

Consider these blade features:

1. rocker radius

2. hollow radius (effects other than skid control and speed?)

3. blade width

4. vertical side honing (blade wider at bottom) (effects other than skid control?)

5. tapered width (blade wider in front)

6. parabolic width (thinner in the middle)

7. Spin rockers - e.g., 1 vs 2 - and other forms of sweet spot

8. K-picks (beyond what MK says)

9. Blade weight (can anyone actually tell the difference?)

10. Anything else.

How do these features affect skating, e.g., how you
(A) balance,
(B) glide,
(C) turn,
(D) spin [e.g., speed and centering],
(E) twizzle [e.g., travel speed, balance],
(F) jump,
(G) etc.
?

I have my own opinions, based on intuitive physics and my own very limited
experience, but would appreciate anything anyone has to say, especially if it is
based on actual experience or authoritative sources. (I have already looked at
the recreational figure skating FAQ, and MK, Wilson, Ultima, and Paramount sales brochures.)

PS, does anyone have current manufacturer contact info for the following skate
blade manufacturers:

ISE
ICE
John Watts

Yes, this is to prepare for my class.

Offline Sk8tmum

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #1 on: December 17, 2010, 06:59:04 PM »
ISE blades are through Jerry's Skatewear.

http://www.jerryskate.com/category/6.aspx

Offline FigureSpins

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #2 on: December 18, 2010, 12:21:49 AM »
John Watts is no longer in business, iirc. 

Michael Weiss bought several pairs of Freedom blades for himself so he had a ready supply, lol.
(Those are the blades he uses for the heel-spreadeagles.)
"If you still look good after skating practice, you didn't work hard enough."

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Offline katz in boots

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #3 on: December 18, 2010, 02:05:54 AM »
1. rocker radius
2. hollow radius (effects other than skid control and speed?)
3. blade width
5. tapered width (blade wider in front)
6. parabolic width (thinner in the middle)

My understanding is that all of these affect speed & manoevrability.

4. vertical side honing (blade wider at bottom) (effects other than skid control?)
weight reduction?


Offline fsk8r

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #4 on: December 18, 2010, 08:52:40 AM »
I've just switched from ISE to Ultima blades. Both are meant to be an 8ft rocker, however there's a more pronounced spin rocker on the Ultima.
I'm now wondering whether being told that a blade is an 8ft rocker is a useful indication of how the blade performs. To me it's of more interest to know about the spin rocker than the overall rocker profile.


Online Bill_S

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #5 on: December 19, 2010, 06:20:54 PM »
I have some experimental evidence that a flat rocker increases speed. When I was in college in the early 70s, I had my blades sharpened by someone who took away most of my rocker.

Man, oh man, could I go fast!

But I couldn't turn sharply.

I concluded that speed skaters had flat rockers for a meaningful reason.
Bill Schneider

Offline Hanca

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #6 on: January 01, 2011, 11:12:15 AM »
I've just switched from ISE to Ultima blades. Both are meant to be an 8ft rocker, however there's a more pronounced spin rocker on the Ultima.
I'm now wondering whether being told that a blade is an 8ft rocker is a useful indication of how the blade performs. To me it's of more interest to know about the spin rocker than the overall rocker profile.



Where do we find information about the spin rocker, as opposed to the rocker of the whole blade?
Do you have any link so that I can find out what spin rockers the various blades have?

Offline spiralina

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #7 on: January 01, 2011, 12:33:01 PM »
Where do we find information about the spin rocker, as opposed to the rocker of the whole blade?
Do you have any link so that I can find out what spin rockers the various blades have?

The MK and John Wilson catalogues show a side profile of all their blades but the pictures are quite small. JW uses a 3-radius pattern for its spin rockers and MK uses a 2-radius pattern, making the MK rockers more pronounced.

Offline Query

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #8 on: January 02, 2011, 11:09:02 AM »
The strength of rocker transitions matters too.

E.g., on an Ultima Dance blade, a lot of strength is required to overcome the initial 8' rocker, that once you pass into the spin rocker, it is difficult not to rock all the way to the toe pick.

A problem with the profiles shown in blade manufacturer catalogs is that they are taken with a camera, creating various shape distortions, and they only show only one blade length, which is also usually hard to figure out.

The manufacturers would be quite happy if you figure this all out by buying one pair of each blade model, and try them all out. I've known people who came somewhat close to doing that.

If you sharpen your own, and are willing to waste a few cheap blades experimenting, you can create different blade shapes, and see how they skate.

Offline Hanca

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #9 on: January 03, 2011, 07:03:32 AM »
The MK and John Wilson catalogues show a side profile of all their blades but the pictures are quite small. JW uses a 3-radius pattern for its spin rockers and MK uses a 2-radius pattern, making the MK rockers more pronounced.

I thought that MK are more pronounced because they have (mostly) rocker as opposed to rocker 8 in JW's blades.

Offline blue111moon

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Re: How blade hollow, rocker, side honing, etc. affect skating?
« Reply #10 on: January 04, 2011, 08:27:19 AM »
"Skateology" a book by Sidney Broadbent goes into all of this is great detail.  The website iceskateology.com lists the publications he's written on his research into blades, boots and technology.