This is a bit of an aside, relating to the speed skating topic drift.
I'm going to base most of this on conversations with Don Giese, who held several of the U.S. Masters age class ice speed records for many years, and who also ran a skate shop in Beltsville, MD, where he was my skate tech.
He and most of the speed skaters I have spoken with sharpen their skates using a technique that creates long thin foil edges on each side (essentially planar surfaces that point into the ice). (HOWEVER, not all speed skaters use that foil edge.) Most figure and hockey skate techs either don't, or create shorter foils. To some extent the foil edges compensate for the lack of hollow. Also, a typical speed skater re-sharpens with every race heat. In effect, speed skates are still very sharp, despite the lack of hollow.
Whereas the tips of the edges in hockey and figure skate blades tend to get rounded off (dulled) a little - in fact most figure and some hockey skate techs do a little of that deliberately - creating a much lower effective sharpness. A slightly dulled edge is a lot less fragile, and can take rougher treatment - though I used to prefer putting foil edges on my figure skates too.
Anyway, this has nothing to do with ROH. Other than that you can use foil edges instead of a smaller ROH to create effective sharpness. But you need to use a fine grade sharpening stone or wheel, and to center it very carefully on the blade. (If, for example, you use a Pro-Filer sharpener, and it has a little too wide a gap, it is very hard to keep it precisely centered on the blade, and it will tend to knock down the foil.) Careful sharpening produces a sideways pointing burr, which you need to carefully polish and repoint into the ice. Also, you have to be very careful of your edges - e.g., you pretty much can't take a single step off ice except in blade guards, which can be inconvenient.
(The o.p. has said he doesn't see a foil edge when he uses Pro-Filer - I'm not sure what gets in the way of that in his case. I do see and feel one - but sometimes remove some of it, especially if I don't feel like being so careful.)
I would argue that hollow on hockey and figure skate blades does two things - it creates a narrower edge angle, which does help with sharpness. But it also gives the thin layer of water on top of the ice a place and a push to move away from the edge. That means they probably don't hydroplane quite as well as a speed skate, which drops the ultimately speed. (Speed skates are also much thinner than figure and hockey blades.) But the sharper edge helps insure that the edges dig into ice more than they otherwise would. That lets you get a lot more push and acceleration.
Speed skaters don't accelerate as strongly most of the time as hockey and freestyle figure skaters - except at the start of the race, when those long foils (or the undulled right angle edges, if they don't like foils) are fully intact - during which they also use a specialized running-with-outwards-pointed-tip technique together with a huge forwards lean to push extra hard, and dig more into the ice. It's kind of fun to try it, as long as your skate session isn't too busy for the speed.
Also, while they generally have no hollow radius curvature, the blades used in short and long track speed skating do have some rocker curvature - typically 18-21', a matter of personal taste. Some elite hockey skaters, when skating on large (Olympic size) ice sheets, actually do use no rocker curvature in the center only of the blade, so they can go faster and stop faster, according to a video I once found on Blademaster's web site. Both the reduced rocker curvature and the "click skates" that short track speed skaters use (outlawed in long track speed skating) lengthen the time-of-contact with the ice, because they can roll through a longer distance and angle.
(I don't know any speed skaters who race on ponds, lakes, or canals. I don't know if they use rocker curvature.)
The side-by-side sharpening dual-blade idea produces identical rocker profiles, but I don't understand why that matters. But they all say that it does.
A few speed skaters, last I talked to them, had started playing with side honed edges. Note that there isn't much blade to side hone - speed skate blades are amazingly thin. So thin I doubt they would take the stress of freestyle figure or hockey skating.
Short and long track speed skates turn constantly, as the skater goes CCW around the oval. That's why their blades are curved to the left.
Topic: Impressions - Changing from a 3/8" to 1/2" ROH (Read 6313 times)