Flat Bottom Sharpening

by Scott Noble
Will flat-bottom sharpening bring a new aspect to the game?

The current hot topic in skate sharpening is alternative dressing forms. I know a lot of  you are about ready to just turn the page right now. And who could blame you after seeing frightening terminology like alternative dressing forms tossed about with such cavalier disregard for reader sanity in the very first line of the article. But bear with me, I promise this isn’t a fashion article. I had to toss out that term at some point so I thought it might be best to just get it out of the way immediately.

However, before I decaffeinate that terrifying term, some of you might need a quick refresher on skate sharpening. So here it is. Most skates today are sharpened with a radius of hollow, essentially a perfectly centered valley down the center of the blade. This hollow forms two edges running along the the entire outside length of the skate blade, giving each skate a left and right edge. A traditional skate sharpening is based upon a radius on the sharpening wheel somewhere between 1/4-inch to 1-1/2 inches.

By varying the radius of the hollow used to sharpen the skates, players can strike a balance between more edge control or more glide. A sharpening wheel dressed to a 1/4 inch hollow leaves a very deep impression in the skate blade. These skates would give more bite than most players could live with—imagine going from hockey stop to cartwheel in one second flat and you have the idea. Conversely they’d offer very little glide. On the other side of the spectrum, skates sharpened at 1-1/2 inch would have excellent glide and so little bite many skaters would end up doing an impersonation of an excited dog on a hardwood floor. Most players opt for a hollow closer to 1/2 inch, which offers a balance between glide and edge control. The simple phrase, “strike a balance,” smacks of compromise. This is where the alternative dressing forms come into play.

Recently, the top two sharpening equipment manufacturers introduced new sharpening styles. Blackstone introduced equipment designed to create a new form that they call the Flat Bottom V or FBV. Blademaster introduced their version of this that is a flat-bottom radius, which they call the Blademaster Form Dresser. Blademaster proved they have a sense of humor, abbreviating their system BFD (which stands for Boulder Fire Department, among other things). Both of these systems enable the sharpener to put shapes other than a simple radius on the skate blade. The goal of these systems is to allow the skater both glide and bite without compromising. Of course, the first question is, “How does it work?” So once again we need to backtrack a little.

In order to understand how the flat-bottom sharpenings might improve glide without sacrificing the bite of skate blades, it seems important to have a basic understanding of how ice skating works. Surprisingly, the question of why ice is slippery is one that science hasn’t entirely revealed yet. Common belief for years was that friction from ice skates (or shoes, for that matter) created a layer of water droplets which acted as ball bearings, causing the skater to slide forward or the shoe-wearer to have a seat. Professor Gabor Somorjai, of the Lawrence Berkeley National Laboratory, is on the cutting edge of ice research (pun intended, my apologies). His research in 1996 points to an unstable layer of molecules on top of the ice surface as the culprit which makes ice slippery. He calls these unstable molecules a “quasi-fluid level.”

What does this mean?

So what does this mean in light of the flat-bottom sharpening? I could deliver a phenomenal, in-depth explanation that would make you feel smarter based upon Professor Somorjai’s research. But that would ignore the 2002 research of his colleague, Miquel Salmeron, which determined that ice wasn’t actually very slippery . . . uh, OK. Long story short, we live in a world that can produce at least four brands of blankets with sleeves; put the Internet, a camera and phone on one pocket-sized device; and can produce a Chia Pet version of the president . . . but we’re not quite sure how ice works. However, while we aren’t sure of the scientific properties of ice that make it functional for skating, we do know how skating works. Yes, I could have skipped right to those points, but then I would have missed the opportunity to reference two Berkeley geniuses and poke fun at two of our society’s silliest innovations.

So how does skating work you ask? It’s the combination of two elements that makes it possible: slip and grip. Slip allows skates to glide forward, while grip allows us to propel ourselves and do important things like turn and stop (important to most of us, anyway). While we don’t know exactly why, we do know that having more blade surface on the ice (as with a shallow radius of hollow sharpening) creates more slip. This is the basic premise behind the new alternate form dressings. By going beyond a simple arc to a more complex shape, as pictured below, skaters can improve the slip while maintaining the same level of grip.

. . . Or so the theory is.

Those who haven’t used a flat-bottom sharpening probably have the same questions that I did before trying it. Does it make enough difference for recreational skaters to benefit? Does it make enough difference that it’s worth paying the premium most shops charge for it? Will the transition from a traditional to a flat-bottom sharpening be seamless? Do skates stay sharp as long with flat-bottom sharpening as traditional hollows? Anyone know where I put my car keys? Is one of these two form dressing systems superior to the other?

Thanks to the generosity of the good people at Blademaster, I have answers to all of these questions. I’ve been test driving the Blademaster Form Dresser for two weeks and have compiled feedback from skaters at various skill levels and ages. The answers to the above questions were for the most part positive. You want details? Statistics ahead!

Of the players I polled, 98% felt improved glide over a traditional sharpening. This seems a surprisingly high number. Also interesting was that 62% thought their edge control was improved compared to only 20% who didn’t think their skates felt as sharp. An impressive 76% of my Guinea pigs . . . er, customers felt that the new sharpening improved their skating, although oddly a few noted better glide, better edge control and no notable improvement in their skating. So perhaps there is some level of truth in the words of Benjamin Disraeli, “There are three kinds of lies: lies, damned lies, and statistics.” So let me drop one more important statistic and be done with them—62% of respondents indicated that they’d be willing to pay more for the flat-bottom radius. That one might be the most significant.

I’ve personally been skating on the flat-bottom radius for two weeks now. The increase in glide that I noticed is phenomenal. Edge control was slightly improved for me as well. But perhaps the most important part was that the transition from a traditional radius was instant and painless. My first thought was that I should keep the BFD a secret to give myself a slight edge over my competition.

Not all skaters made the switch seamlessly though. Players switching from shallow hollows seemed to have the most positive experience. Several players switching from 3/8-inch hollows mentioned that the skates felt less stable when standing still, which confounded me at first. I was finally able to divine from one of them that what they perceived as a negative issue was with the very thing that we were trying to improve. He didn’t like the improved slip when taking face offs. Having been on a very deep hollow that minimized his slippage, increased glide seemed a liability rather than an asset. Conversely, all of the skaters who were previously skating on hollows of 5/8 inch or shallower had very positive feedback about their transition.

How long will a sharpening last? Blademaster’s BFD sharpening creates arches on the bottom of the skate that are very similar to those of a traditional sharpening. I’ve been on my skates 10 sessions and they’re still quite fresh. I generally sharpen my skates after between 10 to 15 sessions since I skate on a shallow hollow, so I’d say the BFD is going to be in the ballpark of a traditional sharpening for durability.

So what’s the bottom line?

For one thing, my car keys were on the kitchen table. More important, the new form dresser sharpening systems won’t improve your hands or your shot, but they might give you an advantage on your skating. I proved both points my first day on the BFD. I walked right around one of the opposition’s better defensemen. Once in the open, I shot the puck directly into the goalie. Regardless, skating is arguably the most important part of the game. I’d recommend that everyone  at least give it a try. And if you find something that gives a similar improvement in hands, let me know.

How does it feel skating on the BFD?

The design of the Blademaster BDF sharpening makes skates feel different in a number of ways. The benefit is obvious—an increase in glide.

However, one of the first things many skaters notice is stability when their skates aren’t on edge. The reason for this is simple: While the edges are as sharp as or sharper than those of a traditional sharpening, the edges don’t dig in as deeply when a player’s skates are upright. So when tracking
in a straight line, skates sharpened with the form-dressed sharpening can feel a little less stable.

However, when on edge, the BFD offers a slight increase in bite for most skaters. For cornering, the BFD excels, actually offering increased control along with improved glide. However, a skater’s style also comes into play.

Aggressive skaters benefit the most from the BFD, while those with a more upright skating approach in their turns will struggle to gain the benefit of the sharpening. So, if you give it a try, make sure you lean into your edges, bend your knees and skate aggressively. If you skate hard, you’ll likely love the new sharpening.

Try it out yourself and let us know! Do you already use a flat bottom sharpening? How do you like it?  

NOTE: Thank you to Blademaster for supplying their equipment for the purpose of this article. Although the flat-bottom sharpening technique is offered by both Blademaster and Blackstone companies, the customer surveys and opinions here are based on the Blademaster system only.
Visit BladeMaster.ca and BlackstoneSport.com for further information.

This article first appeared in our Winter/Spring 2010 issue.