Apparently hockey teams have enough money to try out lots of new ideas. Quite often manufacturers even give them new equipment to try out, so they can say that the pros have used it.
My understanding was that a lot of pro hockey players tried it (which is enough for the manufacturer to advertise that pro hockey players use it), but relatively few of the pro hockey players embraced it. But that may be wrong - my info came from a hockey pro shop owner who didn't have the appropriate equipment. He claimed the possible advantages - it is a rather small change in the shape of the edge - are outweighed by changes to that shape that occur when hockey players stop very fast or smash their skates into each other.
There are a lot of other things that pro hockey players have similarly experimented with, but most don't use. Like electrically heated blades, and using thin concave instead of thin convex areas on the blade to prevent side-slip.
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As best I understand it, edge shapes are a compromise between two ideas:
1. Allowing a long, fast along-blade glide on the one side. This is best achieved by a flat cross-section - infinite hollow radius.
2. Preventing slide slip, as well as giving you strong pushes and stops. This is best obtained by a very thin sheet metal-like extensions - the "edges" - at the sides of the blade, which cut into the ice to prevent you from sliding sideways, and give you a stronger push, while creating very little drag to sliding along the blade.
These two ideas fight each other.
In a standard hollow cut, as with almost all sharp steel tools, the tip of each edge is essentially a reshaped, polished sharpening burr. Essentially, when you grind a blade, the tip is knocked over to the sides, away from the abrasive grinding surface, by contacts with the abrasive surface. In addition, though this is controversial, the steel may be reshaped to stretch and push out additional metal into that tip, which becomes the "lip" or "sharpening burr". When the sharpener straightens the edge with a fine grained flat grinding stone, it polishes the tip, and reshapes it to point downwards into the ice. The result is extremely thin. Some sharpeners feel it is too thin, and is too different during the first hour or so from remaining hours of use, and deliberately grind off the sharpest part, but there is still a relatively thin part that cuts into the ice. (Reshaping and polishing the edge is commonly called "deburring" - but does not actually remove the burr. However, in some metal shop work, I think "deburring" sometimes refers to removing sharp edges altogether.)
In a flat bottom V, the standard cylindrical concave hollow shape is replaced by a concave V shape. Most of the time, that part has relatively little contact with the ice, and may not be very important, though I can't prove that.
But in a flat bottom V, I think they get rid of the sharpening burr altogether, and grind to shape a much thicker sheet at the sides of the blade. Perhaps that makes some sense for hockey, because hockey players frequently knock down or smash down their edges, which a thicker edge would resist.
But in principle, the thicker that edge, the slower and shorter the glide, because it has more drag in the ice - or you have to push harder to get the same speed. A flat surface hydroplanes over the ice, which is why speed skates are ground flat across the blade (infinite hollow radius), and also have much less curved rockers.
Thick edges may be OK for some hockey players - players are typically on the ice for maybe 45 seconds at a time, during which they spend a lot of time pushing hard to accelerate and stop. In addition, the typical middle length of a hockey blade has a less curved (longer rocker radius) longitudinal shape than a figure blade, which lets them push harder and stop harder than figure skaters, which is very hard on the edges.
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But that is all theory. I've not tried flat bottom V, and probably not a good enough skater to notice the difference.
But if you try it, tell us how you like it.
At a rink I skate at, in Bowie, MD, the new pro shop managers were sold on the flat bottom V idea, when they bought a new, very expensive sharpening machine made by Blackstone, which I think owns the patents on flat bottom V. I haven't asked any skaters whether they like the flat bottom V, or whether it is only used for the hockey players. I suppose I could.
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Here is Blackstone's link, which includes a description of flat bottom V.
Topic: Flat bottom V hollow sharpening (Read 3976 times)