What is a secondary rocker?

[Arwen17]

https://www.johnwilsonskates.com/products/gold-seal-revolution
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They added a new column to their skate comparison chart. What is a secondary rocker?

[Loops]

The spin rocker maybe?  Kinda weird that they're inventing their own terminology if so..... 

And what would be, do you all think, the difference between a "standard" and "subtle" secondary rocker?  (See the Coronation series)

I guess this also means that the CorDance is not just a cut off CorAce as  I always thought....

[tstop4me]

Yes, in this instance, "secondary rocker" refers to "spin rocker".  Wilson is not cooking up this terminology.  I've seen it elsewhere.  From a grammatical consistency perspective, it makes sense when used in conjunction with primary:  primary, secondary, tertiary, ....  Note that the "primary rocker" is often also referred to as the "main rocker".  "Secondary rocker" is a more generic classification than "spin rocker", since that portion of the blade is used for moves other than spinning.

Caveat:  Some references refer to a "compound spin rocker"; i.e., a spin rocker with, e.g., two radii.  They will then refer to a primary spin rocker and a secondary spin rocker.

It would be much clearer if Wilson followed Paramount's example, and gave the nominal target values of the radii for the spin rocker instead of the vague "aggressive", "subtle", and "standard".  Even then, as Bill's measurements have shown, however, real-life profiles are more complex, and can't be characterized by one or two values.  Especially taking into account manufacturing quality control and the vagaries of sharpening by techs.

[Arwen17]

If it's the spin rocker, why is coroAce subtle? Isn't that supposed to be the best blade for spinning?

Gold Seal is aggressive and I love what it does for my MIF turns/twizzles and my axel take off pivot, but I don't like how easy it is to go too far on forward spins, camel spin especially, and end up drilling for oil. Back spins of all types are fine and unaffected.

[Query]

Is it possible that the spin rocker(s) they use actually depend on the length of the blade? I've always wondered about that. A guy who sharpened for Riedell (a long time ago - before their were Riedell blades) told me he didn't think the front of the blades (on MK and JW blades) varied with size, but it makes sense to me - perhaps a small person might be better off scaling the spin rockers and corresponding lengths that those rockers are used over.

I guess it makes complete sense (to them) that they do not give precise specifications. They wouldn't want to make it too easy for another company to say they have successfully imitated their blades. Also, if they failed to create exactly the specified shape, people would complain. The only figure skate blade company I know of that has sometimes given precise specifications for at least some of their blades is Paramount.

It would be so cool if someone would measure the exact shapes of all the common blades, in all the common lengths, and publish them. Of course, that would be a lot of work.

[tstop4me]

If it's the spin rocker, why is coroAce subtle? Isn't that supposed to be the best blade for spinning?

Gold Seal is aggressive and I love what it does for my MIF turns/twizzles and my axel take off pivot, but I don't like how easy it is to go too far on forward spins, camel spin especially, and end up drilling for oil. Back spins of all types are fine and unaffected.

*  I don't recall previously seeing (here or elsewhere) posts stating that the Coronation Ace is "the best blade for spinning".  The usual context is that a skater posts that she's wearing beginner or intermediate Ultima (or other brand) blades with a relatively flat spin rocker, and complains about her spins.  Others then chime in that she should switch to a Coronation Ace or MK Pro (blades with a more pronounced spin rocker).

* Also, the Coronation Ace is an intermediate blade, while the Gold Seal is an advanced blade, so wouldn't a better comparison be between the P99 (also listed as having a subtle secondary rocker) and the Gold Seal (aggressive secondary rocker)? 

* Not sure that a "subtle" or "aggressive" spin rocker (whatever those terms mean) is dispositive of "the best blade for spinning".  Individual preference comes into play.  By analogy, the P99 has "aggressive toe picks" and the Gold Seal has "subtle toe picks"; yet elite skaters land triples and quads with both pick patterns.  And elite skaters pull off fantastic spins with both spin rockers.