Impressions - Changing from a 3/8" to 1/2" ROH

[Casey]

Why not try in between around 7/16"'or so first?  Though I don't expect you'd want to do that now...

[Casey]

This is a great video!  https://www.youtube.com/watch?v=3rj0w0x-0yw

At first I was confused because they claim that a deeper ROH can yield faster skating, whereas you're saying you got more speed on a shallower ROH.  Then I reckoned that may be because with a deeper ROH you can push a lot more into turns around the end of the rink to gain a lot of speed and so forth, but it probably takes more work to keep that speed up once gained.

[Bill_S]

Keep in mind that speed skaters hone their blades dead-flat on the bottom. There are some videos online showing how they use jigs and flat grinding stones to hand-sharpen both blades simultaneously. Flat is essentially an infinity ROH, and we all know that those guys are fast.

Their blades are very thin compared to freestyle blades, so that's another data point.

There are a lot of variables at work.

[Casey]

I've done a small amount of speed skating.  They are low-top boots, very soft, so deep knee bend is easy as well as flexing the ankles for precise control that's impossible in figure skates.  The blade has no curve to it either, so a much longer portion is in contact with the ice at all times - probably 10 times the surface area.  It's not possible to turn on speed skates - one must step onto the other foot to change direction.

[Query]

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.

[Bill_S]

Just to follow up again...

I skated on 3/8" in Columbus yesterday, and I prefer this ROH. I didn't have slip when doing fast cornering or with strong pushes. However glide is reduced again and it will take more muscle to keep speed going. Regardless, I like it better for all-round use.

I find it interesting that three-turns and brackets were very similar despite the ROH I had. I couldn't tell which ROH I was using when doing them. I didn't expect that.

The 3/8" ProFiler took a beating changing the ROH to a smaller one. I can tell that the coarse diamond stone isn't what it used to be. I've had this sharpening kit for a few years now, so I've received my money's worth.

[Bill_S]

One more follow-up...

Someone here is interested in how close the Pro-Filer can get to the toe pick. While I was changing back to 3/8" from 1/2", I needed a way to tell when I had removed metal to the edges. I sometimes use a blue machinist's dye called Dykem. Oil doesn't remove it. I use oil as a sharpening lubricant.

Here's a shot of the 1/2" ROH configuration before I began to sharpen back to 3/8". It had been dyed before starting...



After about 10 minutes with the coarse stone, the dye remaining indicated that I still hadn't reached the edges. They still had dye on them. When going to 3/8" from 1/2", there's a lot of metal to be removed from the center of the blade first.



I spent over half-hour on each blade until I reached this stage...



There's a little blue left right behind the pick, but that part will never touch the ice anyway.

[Casey]

When going to 3/8" from 1/2"

Other way around...

That's really close!  Have you noticed that it makes any impact to how the blades feel on the ice over a typical sharpening that ends farther back?  Is that tape on the side of the blade to prevent scratches?

[Bill_S]

No, that's what I did. I had been using 1/2" and returned to 3/8". It means removing a lot of metal from the center before you reach the edges.

The tape does protect against scratches, but it's also necessary to take up some slack in the Pro-Filer's slot.

My blades have never been machine sharpened, so I don't know what it would feel like if the sharpening stopped further back.

[Casey]

No, that's what I did. I had been using 1/2" and returned to 3/8". It means removing a lot of metal from the center before you reach the edges.

D'oh, I read that backwards, oops!

My blades have never been machine sharpened, so I don't know what it would feel like if the sharpening stopped further back.

Wow, that's an impressive fact!  Now I'm tempted to attempt the same feat when I get new blades...  I'll have to read up on the Pro-Filer.  Anything to be aware of?

I'm still curious, have you tried 7/16" on the same blades?

[Bill_S]

No, I haven't. The Pro-Filer company doesn't sell a true 7/16" regardless of what their advertising claims. If you want to know more, go to the end of my webpage about using the Pro-Filer - http://www.afterness.com/skating/profiler.html.

The last time I was on a 7/16" ROH was in the early 2000s on my first pair of Riedell Gold Star boots. It was the last time that I had a shop mount my blades or sharpen them.

[Query]

Wow, that's an impressive fact!  Now I'm tempted to attempt the same feat when I get new blades...  I'll have to read up on the Pro-Filer.  Anything to be aware of?

You don't want to use the Pro-Filer to make major changes to blade shape - you will wear it out, and will need to buy a replacement stone. If you look at the o.p.'s other thread, he pretty much did that.

Properly used, the Pro-Filer is a good tool, and is also rather pretty. But be sure to trace (or photocopy) the original rocker profile, so you can restore it if it gradually changes - as it will.

I have some quick notes on using Pro-FIler at http://mgrunes.com//boots/BootBlade.html in the section labelled "Quick and dirty instructions for sharpening figure skating blades, using hand tools".

However, not everyone agrees with everyone else on how to do things - some people here will disagree with some of what I say.