Rockers Explained

A short story about figure skate rocker radiuses

I had been in business for a little over 2 years.

My sharpening business was in a single sheet facility and I took up residence in the “first aid” room located in the back next to the Zamboni room.

The promise was they could use the room any time they needed first aid, but since I was the furthest room from the entry, all injuries went towards the front of the building. The customers knew where to find me and I was comfortable, except it was a long walk to the bathroom.

As I made that walk one day, a good customer stopped me in the hall between the rink and the front lobby. With an expression of more pain than anger she told me that I had ruined her rocker. The rocker is the radius, measured in feet here in the U.S., from the front of the blade behind the toe-pick, to the heel of the blade. The side of most blades is usually shiny chrome, until you get to the bottom edge. About an eighth of an inch along the bottom of the blades there is a dull line that runs from behind the toe pick to the heel. Some call this the tempered part of the blade and others refer to it as the life of the blade.

Neither is actually true, but the majority of people, both skaters and skate sharpeners alike, use this line as the pattern for the blade’s rocker. She showed me how the dull line was fat at the front of the blade and got skinnier as you followed it to the heel, till it was almost gone.

I apologized to her first, but then explained that I only see one side of the blade while I sharpen the skates. Since the toe-pick is always pointing left as the blade is mounted in the sharpening jig, I only see the left side of the skate while it is on the sharpening machine. As I turned the blade over, so she could see the other side, I explained that I am always very careful not to change that rocker, and the line on the other side was perfectly even from toe to heel.

Not long before that, in the summer of 1989, I spent the better part of a week with P. Joseph DeLio. I responded to an ad in a skating magazine, which offered, for a fee, 1-on-1 professional training on how to sharpen figure skates by a master skate technician. A couple phone calls later (this was before internet) I learned he was the skate technician who worked at the Broadmoor in Colorado Springs, where the US Olympic Figure Skating Team practiced.

Though I had been sharpening skates since I was a teenager, (I bought my first machine at 15 to take care of my skates and my team mates when we were on the road) I was unwilling to touch a pair of high level figure skates because I knew I did not have the knowledge necessary. After spending 4 days with Joe, learning all his secrets, I was prepared to go into business.

I studied hollows for different disciplines of skating, including a special ‘Patch’ sharpening technique that would fool the judges. I was shown how to mount blades and do minor repairs to figure skating boots. I was shown how to use special equipment and tools I would need to take care of high level figure skaters. I was even introduced to Sid Broadbent who was finishing a paper called Skateology and was promoting a new skate sharpening machine he had just developed.

Strangely enough, there was little discussion about the rockers on skating blades. We worked on maintaining rockers and how dancers usually had more rocker than freestylers, as well as how to adjust toe-picks, but nothing about measuring the rocker of a blade.

Back in the hallway with that parent I handed her back the skate. She left satisfied that I had not damaged her blades, but I realized that I was not satisfied with my response. If I can’t trust the lines on the skates, then I have to figure out how to maintain the rocker with some tool and I knew that tool was not available at that time.

So I made my own.

I made tools that could measure eight different rocker radiuses. The greater rocker, or smallest radius, started at 6 ft, then 6 ½ ft, 7 ft, 8 ft, 9 ft, and I made 10 ft, 11 ft, and 12 ft for measuring the hockey player’s skates.

(I know it does not make sense, but “more” or “bigger” rockers are actually smaller radius measurements, and “less” rocker or “flatter” are the larger radius numbers.)

It was a bit more expensive than I thought it would be, but in the end making the tool was actually the easy part. Finding the specifications on all the different blades was the challenge. Again, this was before internet at a time when very few people had computers in their homes and mobile phones were attached to cars and far too big to stick in your pocket. The only way to get this information was to measure every blade I came in contact with.

After a couple of years measuring every new blade, every used blade and recording the measurements in files I kept on my skaters, I was able to come up with blade profiles that made sense. The skating coaches basically categorized blades into 2 types; jumping blades with flatter rockers and toe-picks low to the ice and spinning blades with more rocker and toe-picks that were higher off the ice.

Remembering the dreaded “Factory Grind” could not be trusted straight out of the box, the multiple measurements fell into areas that, over time, showed a preferred radius for every blade. Up until about 2005, by knowing which blade certain coaches preferred to put on their more advanced skaters, I was able to make suggestions to skaters about which blade they should use just by asking which coach they were with.

For example; a Wilson Gold Seal usually measured between 6 ft and 7 ½ ft rocker, with a toe-pick measuring between 3/16 and 1/4 inch off the rocker radius (laying the radius bar along the bottom of the skate and then measuring the distance between the bar and the lowest toe-pick, gave me a way to measure toe-pick heights.).

The intermediate profile that matched those specs was the Wilson Coronation Ace. Thus giving a skater a path to follow from their beginner blade to the blade they would use for doubles and triples. The MK Professional always measured between 7 ft and 9 ft, so I would recommend the higher level blades MK Phantom or Wilson Pattern 99 because they both measured about 8 ft but with bigger toe-picks that were only 1/8th to 1/16th of an inch off the rocker bar.

The flattest rocker was MK Gold Star with a rocker radius of 9 ft-10 ft. Luckily, the Wilson Coronation Comet also measured 9 ft-10 ft, so the transition from intermediate to advanced blades was only about getting used to bigger toe-picks. Dance blades were always the most rockered, measuring between 5 ½ ft to 7 ft radius.

Then, just before the calendar year switched over to the 2000s, MK and Wilson combined into one company. Shortly thereafter they upgraded their manufacturing technique, now using laser cutting to manufacture the blades. The accuracy of the rockers became massively more consistent, except that they also changed their specifications on the blades. Now all MK blades are 7 ft rockers and all Wilson high end blades are 8 ft rockers, including the Gold Seal and the Dance 99.

So now, what used to be the flattest blade on the market, the MK Gold Star, has more of a rocker than the Wilson Gold Seal which used to carry the largest rocker of all the freestyle blades. For some reason they left the Coronation Ace at 7 ft and some of the lower level Wilson skates at 7 ft. But now if you start your doubles in a Coronation Ace there is no high level blade that matches that profile.

Unless you ask me to change the factory grind on a Gold Seal.

The Wilsons’ Coronation Comet is still flatter than the others, but has no advanced level blade to step into. The first 10 years after this change was very challenging because there was a mix of old inventory and new inventory. When skaters showed up with new skates to be sharpened I had make decisions based on the skater’s age and the time they have been skating in that style blade as to whether to match the old rocker or go with the new specifications.

The biggest concern and challenge I have is that the coaches are unaware of the changes that have happened over the years. Fortunately, so far most of the skaters have made the adjustment to the new blade specs. The one nice thing for me is that the “Factory Grind” is now more consistent than before, translating into less work for me on those first sharpening straight out of the box.

Emily Chan                       ½ in hollow          8’ rocker          Gold Seal

Vivian Le                          7/16 in hollow       8’ rocker          Gold Seal

Clare Untalan                  7/16 in hollow       8’ rocker          Paramount

Angela Maxwell              13/32 in hollow     7’ rocker          Gold Seal

Amy Howerton               7/16 in hollow       8’ rocker          Patt 99

Steven Pottenger           ½ in rocker           8’ rocker          Patt 99

Sydney Schmidt              5/16 in hollow      7’ rocker          Gold Seal

Christopher Pottenger   5/16 in hollow      8’ rocker          Patt 99

Andrea Gardiner             Lost files in move from Houston

Chris Browne                   Lost files in move from Carrollton