A Guide To Your Blades
Ever looked at your blades and think, how do they work? How do I sharpen them? How often do I need to sharpen them? What grind do I need? Do I have the right blades for what I am doing? Whats a rocker? Why do I need a toe pick?
All sound familiar?
Well your not alone. All these questions are examples of what every skater asks, but no one can always give you a straight answer. Well we are going to try and answer some of these questions on this page. Don't get me wrong, you're not going to walk away a blade master, but it is important to know about your skates and blades so you can maintain them. It's also important to know what you want and ensure your blades are not damaged in the process.
Maintain your skates
When skating, it is important to have skates that are well sharpened. This means that you should sharpen your skate blades every now and then to restore the edges and remove any light rust. Generally speaking you should resharpen 10-15 hours of skating on indoor ice or when damages on the skate blade are noticed. Outdoor ice is generally tougher on the skates. This means that you need to sharpen more often.
When a skate is pressed against the ice, its edges will dig into the ice. This is what gives you the grip and glide abilities. The grip depends on the angle of the outer edges, the glide depends on the shape of the skate blade underneath. Body weight, skating skill, the contour profile of the skate, and ice conditions (indoor or outside) also effect the grip/glide.
Sharpening of a skate hollow
The most common type of sharpening is called ROH (radius of hollow) or hollowness. Here the shape underneath the skate blade is a centered circle arc. This type of sharpening is used by most people, such as ice hockey players, figure skaters and recreational skaters.
Finding a perfect hollowness will require a lot of testing. A general rule used in Europe to find a suitable radius of hollow (in mm) is to divide the body weight (in kg) with π (3.14). An example would be to take 75kg/3.14 which gives 24 mm (then you can withdraw 2-3 mm if you want more bite).
A deep hollowness will be more fragile and less durable then a shallow hollowness. This leads to more frequent sharpening being needed.
Clean those skate edges
When a skate has been sharpened to get sharp edges underneath, burrs will arise on each side of the skate blade. A hand hone (whetstone) is used to remove them by pulling it along the sides. Now you will have perfect sharpness!
Check The Grind
Look at the hollow of the blade
Once you are done with the sharpening, the blade surface should have a smooth finish. A poor finish (wavy pattern or snake skin pattern) is a sign that the grinding wheel needs to be redressed. If you still get a poor finish and blade chatter, then this is a sign that the diamond is dull and needs to be replaced.
A tip is to use your fingernail and see if those edges are sharp. If they are not then you need to sharpen that skate more. When you are more experienced you can instead use your fingerprint areas (thus saving your finger nails!) to check the sharpness instead.
Figure skates are wider than regular skates and they have toe picks (master picks and a drag pick) that cause some unconvenience when sharpening. The blade thickness also varies among figure skating categories.
The bottom toe pick (or drag pick) should be ground down an amount equal to that you have sharpened away from the skate blade. Otherwise the drag pick will get a different relative position than when the blade was new. An easy way to check this is as follows: before you start sharpening, you place the skate blade against a flat surface, tilt the blade so that the drag pick touches the flat surface and measure the distance at the rear end between skate blade and flat surface. This distance should be kept constant.
After you have had the skate sharpened you should measure again and then remove material from the drag pick so that you restore the previous distance. By doing it like this you will always have the same angle between skate blade and drag pick.
If you lean the blade forward against the ice, you can only go so far before hitting the drag pick. This position is called the "Forward Balance Point". When you spin, you are skating on this point, with the drag pick just touching the ice. Because of the drag pick, you cannot skate on the part of blade between the forward balance point and the drag pick. This no-skating zone does not come in contact with the ice. New blades are not sharpened in this area and there is really no need for a hollow sharpening here. Instead when you grind down the drag pick to keep the skate blade construction in the same angle you can grind down this area a bit as well.
A general rule is that good figure skaters should use a ROH between 11-16 mm (7/16"-5/8"). Advanced skaters can go as shallow as 19 mm (3/4").
Sharpening skates for a plastic ice is a bit different compared to regular sharpening. When a skate has been used on plastic ice, the skate blade will be covered with plastic material. This needs to be removed before sharpening. The easiest way to do this is by using some sort of solvent. You might also have to clean the blade support roller in a similar way after sharpening a skate since the plastic material will get there as well. The grinding wheel will also get this plastic material on it, decreasing its effectiveness. So you need to dress it more often than usual.
When skating on plastic ice you should always have your skates sharpened with a hollowness. Otherwise you will not get any grip at all. You should also use a deeper hollowness than what you normally have when skating on regular ice. Those who are used to skate on flat sharpening should have a hollowness around 25 mm. The plastic ice is very tough on your skates so you will have to resharpen quite often (around every 1-2 hours).
There is a difference between skating on a hard (fast) ice compared to skating on a soft (slow) one. When skating on a soft ice (above -5 °C) your skates will sink deeper into the ice. This makes you move more slowly and you will get more tired. A hard ice (-5 to -8 °C) requires more edge to give a good grip.
By adjusting the hollowness you can get the same feeling on both types of ice. A soft ice requires a more shallow hollowness while a hard ice requires a somewhat deeper hollowness compared to your standard hollowness.