Comparison between MK Pro vs Ace

[Bill_S]

This is split off from an earlier thread concerning a purchase of blades and boots. I thought that the info here might deserve it's own thread.

I purchased two different blades in 10-1/4" length. I have been making some observations about the differences between them. In the other thread, I compared weight where I found the Aces in the 10-1/4" size to weigh 360 grams and the MK Professionals to weigh 355 grams. That's very close.

The edges on both blades were sharpened at the factory to a reasonable degree. On a couple of the blades, one edge appeared just a bit sharper than the other by feel. Most purchasers have them re-sharpened anyway, but these were still skateable with the factory edge.



The toe picks were visibly different.

Aces...




MK Pros...



Note the wicked looking top pick and bottom (drag) pick compared to the Aces. The top pick is the one that I call the "shin pick" for when you are skating with a partner. You'd have to be especially careful with the MK Pros!

I performed the heel lift test where you rotate the front of the blade down until the drag pick touches, and measure how high the heel lifts. Both skates measured 1.3" heel lift. When skates wear, the lift is reduced. This is a baseline measurement for the future.



As expected, the mounting plate hole patterns differed. Darn! Wouldn't it be nice if manufacturers created a standard to make switching blades easier?

The Aces had the adjustment slots toward the rear...



MK Pros had the adjustment slots toward the front...



Not apparent in these photos is that the mounting surface of the MK Pros is cupped. The front mounting plate of the Aces is flat both front to back, and side to side. The boots are rounded a bit on the bottoms, but not to the extent that the MK is cupped. Both will bend the sole of the boot to their respective shape when mounted, but personally, I'd rather have a flat plate like the Ace for reasons that I won't get into here.

The last experiment for today's look was to trace each blade rocker onto sheets of paper, then scan them into Photoshop. In software, I was able to align them to highlight profile differences. I found a couple of surprises there.



Both blade tracings aligned and overlaid, with the Ace tracing tinted red...(clicking sometimes enlarges the picture)



Here's an enlargement of the area close to the spin rocker..



There is more of a hump on the Aces near the spin rocker. The MK Pros are supposed to have a smaller spin rocker radius, but it depends on where you define the spin rocker. Very curious!

I also noted that the Aces are a bit shorter.

I'll continue characterizing these blades in the future, but some of you may be interested in the differences discovered to date.

[Bill_S]

I almost forgot a thing or two.

I measured the stanchion height from the blade to the mounting surface (where plate meets boot). I took the measurement at two places along each blade. I selected the areas at each of the upright stanchions on the blade itself.

Blade       Front     Rear
MK Pro     1.856    1.894
Aces        1.876    1.881

I also measure the blade thickness at the chrome relief at several points along the blade.

The Ace was 0.161" near the tail, 0.163" mid-blade, and 0.165" approaching the pick. A slight taper! I didn't measure the other Ace blade.

The  MK Pro was 0.161" near the tail, 0.159" mid-blade, and 0.161" approaching the pick.

Now we have some idea of manufacturing tolerances for these blades. It's not perfect, but I'm sure that it's perfectly serviceable.

[MCsAngel2]

I can't believe the two tracings are SO similar around the spin rocker. Clearly, a little goes a long way in blades.

Bill, what blades were you skating on previously?

[Loops]

Very interesting! 

My US tech always whinges and moans about the quality control at MK/Wilson.  Did you measure just one or both blades in the pairs? (I suspect just one....seems like this might be a fair bit of work to get these measurements!)

Nice to have a base, and first set of measurements.  Thanks for this work!

[Bill_S]

I can't believe the two tracings are SO similar around the spin rocker. Clearly, a little goes a long way in blades.

Bill, what blades were you skating on previously?

I am currently skating on Coronation Aces, but a size 10-1/2. I have tracings of it, and if I have time, I might try to compare that to the new ones here. It might be fun to see how size differences are accommodated, but the difference is only 1/4".

Loops - I traced only one blade per model for expediency. Time permitting, I might trace the other two to compare.

[tstop4me]

This is split off from an earlier thread concerning a purchase of blades and boots. I thought that the info here might deserve it's own thread.

Interesting results here.

(a) It's bizarre that the mounting plates are different. MK and Wilson merged under the parent of HD Sports back in 1997.  By now, for economy of manufacturing scale, you would think they would use as many common piece parts and processes as possible.  E.g., previously, MK blades came in 1/3" increments, but at some point they shifted to 1/4" increments, in line with Wilson.

(b) What about the slot configuration on the MK heel plate?  Is it the same as the Wilson, with the slots diagonally opposed on different rows?  That configuration never made sense to me (Eclipse and Paramount have the slots on the heel plate on the same row, as on the toe plate).

(c) Your tracings of the blade profiles are curious indeed.  Paramount concluded that the Ace has a compound spin rocker, 12" radius right behind the drag pick, and 27" radius further back; while the Pro has a single spin rocker, 12" radius.  That was done with a mechanical gauge (3-point fit).  They didn't mention their sample size.  Looking forward to your detailed curve fittings.

[Bill_S]

There are a lot of similarities in the packaging of the two blades, and that looks like something done for efficiency.

The heel plates are different. Here are two photos showing the two...

Ace...



MK Pro...



I'm also curious about what the profile numbers will show.

I'm even more curious about how they will feel on ice.

[FigureSpins]

I measured the stanchion height from the blade to the mounting surface (where plate meets boot). I took the measurement at two places along each blade. I selected the areas at each of the upright stanchions on the blade itself.

Thank you!  I had asked two JW/MK rep about the differences between these two blades and they both said the MK Pro had a lower stanchion height, but neither said the HEEL stanchion was higher than the CorAce.  It explains so much about kids with balance issues and changing to higher-heeled boots.

Bravo for your analysis - you should submit it as a trade journal article, perhaps for the PSA or the ISI Rink magazine?

[Bill_S]

I took measurements of the rockers of both of these blades today. I used a method as before, seen in this thread... http://skatingforums.com/index.php?topic=6925.msg82766. One minor change this time is to start measurements at the toe pick root instead of the tail, but that will not impact rocker radius calculations. It's just a coordinate starting point change, and it's a little more elegant that way.



I'm still digesting numbers, but the main rockers of both the MK Pro and the Coronation Ace are nearly the same. The rockers, calculated from three points (5", 6.5", 8") measured back from the toe pick "root", are a little over 6' 8".

Advertised rocker is 7' for both, so I'd say that's pretty good.

More to come.

[Bill_S]

I plotted the rocker profile numbers and expanded the vertical axis to greatly exaggerate the differences between the two blades. The pick end of the blades is on the left, tails on the right. Both curves have been normalized to have the lowest measured part touch zero on the Y-axis.

(Click plot to enlarge on some displays)



tstop4me wrote earlier:

(c) Your tracings of the blade profiles are curious indeed.  Paramount concluded that the Ace has a compound spin rocker, 12" radius right behind the drag pick, and 27" radius further back; while the Pro has a single spin rocker, 12" radius.  That was done with a mechanical gauge (3-point fit).  They didn't mention their sample size.  Looking forward to your detailed curve fittings.

It certainly appears in the graph that the Ace (in red) has a compound curve (3 radii?). It has a bulge at ~1.5" to 3" from the root of the drag pick. The MK Pro curve (green) appears to be a simpler two-curve shape.

BTW, the Ace rocker radius in the 2"-3" area is calculated to be 14.8". The tightest I found so far on the MK Pro is 18.75" in the 2"-3" area. This goes counter to some of the charts that I've seen at retail web sites which claim that the MK Pro has a smaller spin rocker (12") than the Ace. From the graph, I don't think I could find a 12" radius curve anywhere on the MK Pro.

I wonder where the retail sites get their data for spin rockers?

[tstop4me]

I wonder where the retail sites get their data for spin rockers?

This is my guess.  Wilson and MK are tight-lipped about their specs.  And, according to Sidney Broadbent, they really didn't have specs, just some master templates.  The only detailed measurements I've found, other than yours, are the ones from Paramount.  My guess is that the retail sites simply copied the values from Paramount without attribution.  And the retail sites typically only list the Coronation Ace as having a 27" spin rocker radius (which is fairly flat), without going into the finer distinction of a compound radius.  Then, when a blade from another manufacturer is marketed as "comparable to" Coronation Ace or MK Pro, the retail sites simply regurgitate the values for Coronation Ace or Pro, without confirmation. 

As I noted in my review on the Eclipse Aurora ("comparable to the Coronation Ace"), the spin rocker on the Aurora appears to be flatter than on the Coronation Ace (by direct feel on ice and by heel lift measurement; I'm not equipped to do your detailed profiles).  Other skaters have reported the same feel (flatter spin rocker on Aurora than Coronation Ace).  I contacted Eclipse; they told me the spin rocker radius is 23" (no mention of a compound radius).

Paramount makes special note of their CNC profiles, including sharpening.  It would be interesting to see whether their versions of MK and Wilson blades have the specified spin rockers (specified by Paramount, that is).

[Bill_S]

Comparing 2019 vs. 2007 Aces

Well, well, well.

I dug out the tracing from my then-new 2007 Coronation Ace blades and compared it to the newly purchased Aces. They were both new, out-of-the-box blades when traced, with only the factory sharpening.

In addition to the expected difference of being 1/4" shorter, another difference is the extra material near the spin rocker on the new 2019 Ace! That can't be explained by a difference in length. Up-thread, that was also the chief difference between the MK Pro and the Ace. Here it is again when comparing two Aces 12-years apart.

If the new Ace has a bit of extra material near the rocker, I wonder how this will translate to feel on the ice? Will spins be better, or worse? Does it matter once I get used to it?

Either there was a running design change, or it points to a QC issue. The 2019 Ace is shown in red.



Detail of the two Coronation Ace blades (2007 vs. 2019)...



This is getting more interesting all the time.

[nicklaszlo]

Great thread!

[Bill_S]

Thanks, Nick!

Comparing Left and Right 2019 Coronation Aces

Because of the differences between the 2007 and 2019 Aces, I thought that I'd better compare the left and right blades of the new pair before mounting.

I'm happy to report that these two blades are a matched pair. I can't detect any difference in the rocker profile in a tracing. The stanchions show very minor differences, but that will have no effect were the metal meets the ice.

[Click to make picture bigger on some devices]



That's a relief to know.

It's still a mystery why the old Ace blades are different from my new 2019 pair.

[Bill_S]

An Aside

Going out on a limb here, but it might be a valid exercise.

I have been interested in SkateScience dance blades as an alternative to the others. They are sold online, have a 1-3 week wait, and are fairly expensive ($444.24). However I have heard glowing testimonials about how they perform.

Skate Science has a photo of the blade in profile on their site. Go to http://www.skatescience.net/products.html and click on Olympus Dance. I overlaid the MK Pro over the photo to see if there are obvious differences in the rocker profile.

Granted, doing it this way is fraught with unknown problems, but I thought that it would be better than "armchair speculation". Maybe I could tease out some differences.



It looks like the main rocker on the dance blade could be flatter than the MK Pro, so I'd assume that it would be an 8' rocker. That's in character for a dance blade after all. Being a larger rocker radius, the blade would be faster than the MK Pro, especially compounded with the traditionally thinner dance blade. Having less friction, it would feel more "slippery".

I noticed that the spin rocker is flat compared to the MK Pro, with the picks lower to the ice. The manufacturer claims that this blade has a large twizzle sweet-spot, and the flatter spin rocker could be their method for doing this.

However, that's a lot of speculation on my part without the actual blades to trace and measure. Still, I presume that the major differences might be identified in the comparison.

[Isk8NYC]

I wonder if the manufacturers might loan you blades for these analyses?  Thanks for sharing.

[Loops]

I wonder if the manufacturers might loan you blades for these analyses?  Thanks for sharing.

I have been thinking the same thing. If not the tight-lipped manufactures, friendly neighborhood pro shops? Or would one of the skating or Prof society magazines sponsor a more in depth study?

I personally want to know more!!!

Bill- you're awesome!!

[Bill_S]

Thanks for the kind comments.

I wonder if the manufacturers might loan you blades for these analyses?  Thanks for sharing.

I would expect a cold shoulder from the blade makers. Manufacturers would be reluctant to spill their "secret sauce". An analysis might also show that there's little or no difference between two of their blades that might be positioned in different price brackets.

What I'd like to do (dreaming here) is to make some sort of quick-change interface plate between blade and boot. It should allow an experimenter to switch between blades within minutes to try out different makes and models.

Even that has some issues. It often takes a while for someone to get used to just a new sharpening, so imagine switching between different blades in a short time. There are some basic geometry issues too that would not provide an exact comparison to directly mounted blades.

But it would be fun!

[tstop4me]

I would expect a cold shoulder from the blade makers. Manufacturers would be reluctant to spill their "secret sauce". An analysis might also show that there's little or no difference between two of their blades that might be positioned in different price brackets.

I suspect that would be the case too.  There's also the issue of determining the manufacturing variation for each blade.  You would need to establish that before concluding definitively whether the differences between different models of blades are significant or not.  You would likely need a collaboration with a major distributor who would be willing to lend a large selection of blades for unbiased measurements; manufacturers would likely cherry-pick samples.

[tstop4me]

What I'd like to do (dreaming here) is to make some sort of quick-change interface plate between blade and boot. It should allow an experimenter to switch between blades within minutes to try out different makes and models.

It's a pity that previous attempts at blade-holder plus interchangeable runner systems for figure skates didn't succeed (whereas, different interchangeable systems for hockey skates have become common).

[Bill_S]

Comparing Left and Right 2019 MK Pro Blades

This morning, I compared the left vs. right MK Pro blades via a tracing onto paper. They weren't as closely matched as the Coronation Aces, with the right blade having a little more material on the tail end. The extra material is apparent starting from the rear stanchion.

[Try clicking the picture to enlarge it]



Here are details of two tracings, starting with a good rocker match at the front of the blade...



But here is the rear...



Because the difference is at the tail where we don't skate much, it shouldn't matter significantly.

BTW, when I first saw this, I thought that my original tracing technique might have been a little sloppy. I re-traced both blades, but the anomaly remained. I feel confident that it's a blade issue, not one of inspection.

Even though I don't think that it will matter much in actual skating, this does show that QC isn't up to standards required in other manufacturing disciplines. Someone (tstop4me?) speculated that MK and Wilson used templates for shaping blades. Templates can be an excellent way to produce closely matched parts, comparable to CNC computerized manufacturing. They do require maintenance though. Even if that is done well, the sharpening done afterward could affect the rocker.

[Query]

I have sometimes scanned my blades at the edge of a printer/scanner instead of tracing them, for better accuracy. But I have to be careful not to scratch the glass.

I do find it very interesting that the left and right skates in the pair were an almost perfect match, despite the inconsistency often claimed of MK/Wilson factory sharpenings. Could they somehow sharpened together at the factory?

Which shape do you like better for skating - Ace (you mean Coronation Ace, right?) or MK Pro? Why?

I'm a bit surprised at how gradually the rocker radius changes. I feel that a more abrupt change between the spin rocker and main rocker makes it easier to feel where the change is, which gives me a felt reference point for where I am on the blade. But maybe better skaters don't need or want that.

How much of your blade measurement techniques is just for fun, to see if you can do it, and how much do you actually use them to reshape your blade to improve your skating? Do you make your engineering students cook up new measurement systems too? Maybe a good engineering project for your (advanced) students would be to design and build skate measurement tools or even skate sharpeners?

BTW, Skate Science's web site suggested (I haven't looked at it recently) that the shapes were designed to match muscular power curves of elite athletes - e.g., that they take into account how much strength they have, at what points in the roll along the blade, and that they created rocker profiles to match, in order to vault higher into the air on jumps, if I understood correctly, though they weren't that specific. (They didn't explain, when I looked, what their ice dance blades were supposed to optimize.) I haven't seen you skate, but is it is conceivable your strength and power curves don't match the specific elite skaters they designed their blades for?

When I called them, they tried to convince me that their blades,  would nonetheless be optimal for not-so-athletic me, despite the advertised match to the strength and power curves of elite athletes. That left me wondering if there might be more hype than substance to their claims, especially in my case. But maybe that is unfair.

The basic idea - that the blade shape should match the athlete's strength and power curves, for optimal results - makes a certain sense, if the athlete is willing to put sufficient time into learning to use the new blades. I'm just not sure that the curves are the same for everyone.

With your engineering skills, perhaps you could figure out a way to measure your strength and power curves, and derive the optimal blade shape for you, for the kinds of skating you do, and reshape your new blades to match?  That could be a really cool product you could offer, or make your students design - perhaps you (or they) could also design C&C control software to cut blades to match individual customers' strength curves...  

(It's a shame no one has figured out an easy way to rapidly reshape a blade, a la the liquid metal Terminator, so we could rapidly experiment with different blade shapes... Maybe custom sharpening is the closest we can come for now.)

[Bill_S]

Which shape do you like better for skating - Ace (you mean Coronation Ace, right?) or MK Pro? Why?

That's one of the things that want to discover. I've skated in Coronation Aces for almost 20 years. I thought that it might be time to experiment. We all want a magical blade that transforms our skating into something wonderful, but, without evidence, the pragmatist in me thinks that you should pick one, and get used to it.

BTW, I am retired now from teaching.

[Bill_S]

Blade Straightness

One more test, and it's something that anyone can do with their own blades, mounted or not. I checked both sets of skates for straightness using a straightedge. Placed along the side of the blade, it's fairly easy to see if there are any gaps along the length of the blade. I tested both sides because sometimes gaps located at the ends are hard to spot. The opposite side will then show any deviation from straightness more readily, which will be apparent as a gap in the middle of the blade.

Both Coronation Aces were dead-on straight. One MK Professional was fine, but the other blade (right one) had a slight sideways curvature. I'd estimate that it deviates about 0.020-0.025" from straight in the middle. That's about the thickness of a matchbook cover.

Look for the small daylight gap between the straightedge and the blade in the photo below.

[Click to make bigger]



This is not ideal, but it's not a great amount of bend either. I'd probably notice a little "shhh" sound when gliding on it, but it shouldn't affect much else. I've skated on blades like that before, having discovered it after a year of usage.

I can make a little press in the shop to straighten it to perfection.

[Loops]

Very interesting the deviations in quality between the Wilson blade and the MK.

It's a sample size of 1, so doubtfully exemplary (especially considering I've heard warp stories coming out of both MK and Wilson).

BUT, having said all that....who bought who?  Wilson bought MK? The other way 'round? Merge?