A
Complete Guide to the Selection and Maintenance of Skate Blades
Blades are commonly made in 1/4 inch
lengths. Blades also have different widths and radii, as well as
different configurations of the "bulge" (spinning area) and toe
picks. These all have major effects on the way a blade "feels".
Figure skate blades start out in three separate parts. TOE
plate. HEEL plate and the part that actually does the work on
the ice. These are punched out on large presses. The blades are
blanked out of long strips of steel which vary in Carbon content
depending on the quality of the particular skate blade that is
being made (i.e. a Majestic would have a lower grade of steel
than say a Phantom or Pattern 99 Although the steel used for all
blades hardens to the same standard, the better grade would keep
its edge longer (under equal conditions).
Before the three parts are put together to make the skate the
blade section is hardened. This is done in large quantities hung
on a frame and lowered into a high temperature salt bath for a
set period of time to be evenly heated and while still glowing
red are quenched in an oil bath. The shock of the sudden
decrease in temperature causes the steel to harden . However,
the hardness at this stage is too brittle, so the blades (still
on the frame) are put into another salt bath of a lower
temperature to temper to about what is called 60 degrees on the
Rockwell scale. When cooled they are removed from the frames fed
into a machine that grinds them to a set thickness.
The toe and heel plates (already ground) are then brazed to the
blade. There are two methods of joining the parts together. Some
products are all silver soldered. This is a fairly low
temperature braze achieved by electrical coil induction which
causes the heat from the brazing to travel down onto the blade
reducing the hardness to about 40 degrees Rockwell 'C' for about
halfway but leaving the lower "working" half (about 5/16'')
still at 60 degrees. Others on the other hand silver solder
theirs but the top quality blades such as Phantom, Gold Star
etc. are hand brazed with bronze. This operation creates a lot
more heat therefore the blades, by no means soft could be a bit
patchy in their hardness. They are then set into an induction
coil, electrically heated, rehardened and tempered about halfway
up the blade.
You can tell if your blades are hand brazed. If you look at them
you will notice that where the toe and heel plate joins the
blade there is a very large radius. This method is very strong.
Silver soldered skates will have a small bead of braze so the
radius will be much smaller. However silver solder flows well
and fills gaps readily. So, whichever method is used there will
still be 5/16'' or more of correct hardness.
The assembled blade is now chrome plated,
the profile is ground on and the chrome is removed from the
edges by grinding. This is the line that you see each side of
the blade edge. This is removed so that hardened steel and
not chrome is at the working surface. There is of course
extensive polishing and inspection before shipping.
Buying new blades
The blade
length denotes the measurement from the front of the sole plate to the back of
the heel plate. Measure the length of the sole from toe to heel and fit blades
which are 1/4 inch less in length.
Some people believe that they have to buy blades that are super expensive in
order for them to become great skaters. You should buy well-built and
*appropriate* equipment. Skaters gradually upgrade their equipment as their
needs change, for example a skater may need to upgrade skates when they move
from basic skating to their first jumps or from double to triple jumps. Advanced
blades require the skater to perfect his/her technique.
Top of the line blades are designed for very advanced skaters. Advanced
free-style blades have a longer radius and have *large* toe picks. Also, the
portion of the blade that is used for spinning is much shorter than on
intermediate blades; that means that unless you are perfectly balanced and
positioned going into and during the spin you will start rocking on the blade.
Intermediate blades like the MK Professional, Coronation Ace, etc. provide you
more "room" to make corrections and continue spinning even if you are slightly
off balance.
Just because the MK Gold Stars are typically over $400 does not mean that they
are inherently better blades than MK Pros or Phantoms. Starting with MK Pro and
Coronation Ace lines, the blades are all made using much the same materials and
manufacturing process as described above. To put it succinctly, certain blades
are more expensive simply because of supply and demand and a few slight design
modifications like side honing which makes them marginally more costly to
produce.
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Three ways of
checking used blades
1. Look at how thick the dull strip is on the
sides of the blades along the edges. They were three or four millimeters when
new. If they're now thin, then your blade has been sharpened many times. The
concern here is that the rocker may be distorted after many sharpenings, and it
is almost impossible to restore without specialized equipment.
2. Put the skate upright on a table, and check the position of the bottom
toepick. The blade should also be touching the table within one or two inches of
the toe pick. If the blade touches the table further back, it means that the
toe-pick is too low (probably a consequence of successive sharpenings). If the
blades touches closer than 1 inch, the master toe-pick may have been ground off.
In this case, the blades will be useless for learning spins and jumps.
3. Ask your skate sharpener to examine the blade. They can tell you if the blade
is bent, incorrectly mounted or obviously damaged by abuse or bad sharpening.
If the only problem is that the toe pick is too low, ask your shop to grind it
some to raise it. Never have the bottom (master) tooth ground off your blades
unless you only intend to use them for figures.
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Mounting
Skates with improperly mounted blades can be
virtually impossible to skate on. The blade must be correctly positioned and
aligned on the boot. To avoid twisting the blade, the boot heel and sole
contours must match the blade mounting surfaces. If not, the surfaces can be
trimmed with a rasp, or shims can be added between the blade and boot.
Briefly, this is how your skate shop will mount the blades:
1) find the center of the tip of the sole and the center of the heel and draw a
line joining them.
2) place the front of the sole plate of the skate blade in line of the front of
the sole of the boot, and maintain the skate blade along the line drawn. This
will place the blade between the big toe and first toe.
3) Screws may be placed only in the slotted holes, so that you can try them and
make minor adjustments (a blade position slightly closer to the big toe is
sometimes favored). Don't do any jumps until the best position of the blades has
been found and more screws have been inserted.
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Problems with
warping
1. The blade may have shifted sideways slightly
when the front or back pair of screws were tightened on the temp mounts, warping
the blade from front to back.
2. The holes for the permanent mounts might not be positioned perfectly, warping
the blade as in #1 above.
3. The heel might not be perfectly level or flat with respect to the front of
the boot. Old screw-holes may have created bumps on the heel. Or the boot might
have been manufactured with an uneven heel. Such a heel will twist the blade.
Checking for
mounting problems
If you have trouble getting good edges, first
have the blades checked to make sure they are straight, properly sharpened and
mounted perpendicular to the sole. If the problem persists, have someone watch
to see if your blades "make snow" as you try to skate on the edge in question.
If they do, this may point to a mounting problem which can be corrected by a
slight shift of the blade mounting. You will need to tell the person remounting
your blades which edges you are having trouble with.
You can also check if your blades are mounted correctly by yourself (you need
recently sharpened blades for this test to ensure that the edges are even)
- Find a clean patch of ice
- Gather some speed and glide on two
feet on a straight line. Keep your body upright. Your feet should be directly
under your hips. Try this several times, both backwards and forwards
- Go back and look at the the traces:
if the blades are set correctly you should get a set of double lines for each
foot. If one of the lines is consistently thicker than its mate (or if there is
only one line), it means that your weight on that blade falls predominantly on
the edge tracing that line,i.e., the blade is unbalanced.
- If you are leaning mainly on the
inside edge, have the blade shifted to the inside and vice versa. You probably
only need a small shift -try moving it by 1 or 2mm and then repeat the test.
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Rocker
Rocker is the curve of the blade from toe to
heel, and is based on the arc of a circle with a given radius. Thus, if you drew
a circle with a 7 foot radius and placed a blade with a 7 foot rocker along the
inside curve of the circle, it would line up with the tracing, at least at the
rear (tail) of the blade. The curve at the front, behind the toe pick is
somewhat sharper. It is this difference of curvature which allows you to turn
and spin on the front of the blade.
The smaller the radius, the more rocker (amount of back and forth rocking motion
you can get when standing on the blade) it has. With small radius blades, you
can do turns with less chance of falling as there is less blade on the ice. For
the beginner, a 6' radius is fine as, among other things, it is very forgiving
in the toe pick department -- you really need to lean way forward on them to
catch the picks.
The bigger the radius, the flatter the blade. This will generate more speed as
more of the blade contacts the ice. You will want a flatter blade (7 foot or
more) as you become more advanced. When you start learning jumps, you will find
that you need good edge control. Because you have more blade on the ice, you can
start to prepare your body position for takeoff without falling off the edge so
easily.
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Grind or Hollow
Hollow or
grind refers to the concave surface on the bottom of a correctly ground blade. A
small radius creates edges that will dig deeply into the ice, while a larger
radius digs in less, but glides more freely. A hollow with a 5/8'' to 3/4''
radius is recommended for beginners and "all purpose" skates. This hollow will
allow you to sense how a proper edge should feel, and at the same time be
forgiving in things like T-stops. The weight of the skater will also affect how
deeply it should be ground: Usually children will need a deeper hollow than
fully grown adults.
Finally, the width of the blade is yet another factor to consider: A deep hollow
with a 3/8'' or smaller radius will be UNFORGIVING on freestyle blades, unless
you are a child or have a very petite frame. This type of grind may yields crisp
and fast 3-turns, ability to hold a very deep edge when landing jumps, and
allows for fast spins IF you have them centered. An uncentered spin on deep
edges will cause you to travel. On the other hand, such a small radius will be
ideal for dance or hockey blades: Because these blades are narrower than
freestyle blades, the need a deeper grind to get the same grip on the ice.
A shallow "figure" hollow with a 1'' or larger radius will require a more
correct lean to prevent skidding and requires more frequent sharpening, but
yields an easy glide and clean tracings.
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Advanced blade
features
K-pick
The K-pick design consists in a set of extra 3-4
picks to the side of the standard toe-picks. This feature is supposed to provide
more control and better anchorage to the ice on toe-jumps. According to blade
manufactures, the jump height can increase by 5-10% and the jump length by about
20% on toe loops and flips. No significant improvements in height and length
have been reported for the Lutz, although the improved stability on the take-off
supposedly makes for more consistent jumps. Many freestyle blades models,
particularly at the high end range, are available with K-picks.
Side honed and tapered blades
Most skating blades have the same constant width
along its full length. However, some advanced freestyle figure skating blades
have a concave section ("side honing"). Side honed blades are thicker at the
stanchions and the edge stripe and thinner in the middle. You can tell side
honed blades because reflections appear inverted.
Another modification to the edge profile found in advanced blades is "tapering".
Tapered blades are thicker at the front near the toepicks and thinner at the
tail, i.e. the edges are not parallel. Some models or custom made blades
can be both side-honed and tapered.
These modifications make the blade lighter (because of the removed steel) and
supposedly provide a better grip on the ice. Not surprisingly, the more
laborious manufacturing process translates in a higher price. Whether they
actually provide any real advantage is a matter of discussion.
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Sharpening explained
by an expert
Take your
skates to a pro shop or ask some regular skaters at your rink where they get
theirs sharpened. Skate sharpening is NOT a do-it-yourself project! Skates are
expensive and it only takes one bad sharpening to turn them into scrap metal!
1) You have to know and trust your sharpener,
2) Your sharpener has to know you and your needs,
3) You have to stand guard over your skates until they are sharpened by the
proper person.
Skates properly sharpened will have a smooth concave grind accurately centered
along the length of the blades, edges squared (parallel to the bottom of the
boot) and level with each other (inside edge at same height as outside edge) for
the length of the blade. Proper sharpening will maintain the correct rocker for
the life of the blade.
Freestyle sharpenings will have typically a 1/2'' radius concave grind and will
be in a sharp condition. The edges of a deep freestyle grind have the great
advantage of holding jump landings on hard or soft ice and also will outlast a
shallow grind by a considerable amount of time. They will also hold landings on
missed jumps and give the skater that extra split second to catch their balance
and avoid unnecessary falls. A sharp deep grind takes a little effort on the
part of the skater to adapt but is well worth the effort and once adapted to it
will be no problem in future sharpenings.
Figure sharpenings will have 1 1/4'' radius
concave grind and will be in a medium sharp condition. The figure grinds are
extremely smooth and flow freely on the ice. More shallow (greater radius)
grinds have extreme flow on the ice but are usually suitable only for the more
advanced skater.
Combination sharpenings will have 3/4'' radius concave grind and will be in a
medium sharp condition so that the skater can skate figures with ease or they
can be used for general skating. The grind will be of smooth finish and will
flow quite freely on the figures (although not as freely as a true figure
grind). This grind can be used for all jumps and spins and will hold well while
blades are in a sharp condition. This grind is also very suitable for occasional
skaters and some dancers; and is also good for adults to start with.
Skates should be resharpened before they become so dull that you begin to slip
on hard ice (eg: not flooded since last night). This will also minimize the
adjustment you need to make to your newly sharpened skates. Nicks in the blades
should also be attended to. Bad nicks in the edges will ruin the finest
sharpenings.
When the blade is ground down a long way after many
sharpenings, the relationship between the bottom pick and the blade edge
should be maintained by removal of steel from the pick. There should be about
1/2'' lift at the heel before the pick makes contact with the ice. Just because
your blades are ground down past the line of chrome plating, that is not an
indication that you need new ones. There is still lots of life left as long as
the sharpener replaces that "line" and adjusts the pick height.
Beware of how some shops do their sharpening: Some shops flat-grind the blade
first, and then hollow grind. This wears the blade at an accelerated rate.
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Maintenance
There are
two kinds of blade covers, hard rubber/plastic guards and terry-cloth "soakers".
The plastic guards should be worn *any time* you step off the ice. Even "safe"
rubber mats or carpets accumulate dirt and grit from the shoes of pedestrians,
and this grit will nick and round off the fine edges of your blades much faster
than gliding across the ice. Do not leave them on your skates between sessions
as they will trap water and cause your blades to rust.
The cloth soakers are put on after you have removed your skates and wiped them
dry with a rag. They protect your blades from bumping in transit and wick away
any condensation so your blades won't rust. If you still have problems with rust
or want to store your skates, rub a drop of oil or Vaseline along the bottoms of
the blades.
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Back to Equipment
Buying New Blades
Buying Used Blades
Mounting Blades
Blade Problems
Blade Rocker
Blade Grind (or hollow)
Advanced Features
Sharpening
Maintenance
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