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Old May 4th, 2012, 05:36 PM   #73
Armadillo
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-Armadillo said:
"...I am stating flatly that it is the GEOMETRY of the shallower action for the DA5-10-15 style plates enables them to work better for speed skaters than the GEOMETRY of the steeper action DA45 style plates, and NEITHER style plate's action GEOMETRY can be significantly altered by mere cushion or pivot adjustments... "


Quote:
Originally Posted by fierocious1 View Post
BS, The geometry can be changed. That is the point you don't get, You are so used to the non-D/A 45 not lending itself to adjustability. It doesn't take much change on the D/A 45 to see the difference, that it can be altered.
Don't believe it, fine by me. But don't claim things to be fact when you haven't explored it.
Speculation is usually before testing, an unknown. Cushions themselves can be changed to affect the pivot angle thus changing the mechanical response of the plate, making the trucks turn more or less with X(same) input angle.
This argument is not about whether the action's pivoting angle can change, it is about the limits on the degree of change possible.

By just placing your weight on your skate you will change the action's pivoting angle. It will become shallower as the truck tilts upward a bit from your weight load on it. No big deal though, and not going to alter the skates performance profile noticeably.

You can even stretch your DA45 adjustable pivot pin out to the max, and place the necessary taller cushion (or spacer) above the truck. If the truck's cushion platform remains near 90 degrees to the kingpin, and the truck hole stays near to centered around the kingpin, then the trucks pivoting angle is not going to be altered very much at all.

You will certainly raise the deck height significantly, which can be a good thing to resolve wheel bite, but there is no way you can consider this pivot tweaking to be a major alteration of the plate action's pivoting angle -- it remains effectively a DA45, or a DA 44.5 or a DA 46 or a DA44.....


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-Armadillo said:
"...I have been doing these exact same kinds of pivot pin tweaks with Chicago Panther trucks for over five years already, and trying them on a wide variety of different style plates too. No doubt I have tried using them with more frakenplate testing setups than just about anyone. So I do get the picture of what you are up to with your DA45 pivot tweaks..."


Quote:
Originally Posted by fierocious1 View Post
Pivot angle is not a fixed value in 99% of all skates, if you don't understand that you have serious problems grasping what is fact. The only plate out there that I know of that the angle cannot be changed in is the Micro Star(maybe a couple more I don't know of), it is absolutely fixed. Testing is what you need and lots of it, outside the box testing....
Nothing in the universe is "fixed" in the way you imply, and everything vibrates and flexes to some extent.

That being said, you need to realize that when a plate is designed and the choices for the plates style of action geometry are made, this absolutely does make the action's pivoting angle "fixed" ==> FIXED WITHIN NARROW LIMITS

I am not denying that you have the ability to play around within this available, but limited, range of DA45 suspension tweaking wiggle room, but I suggest you going way overboard in exaggerating the degree of DA45 plate performance changing results that can be accomplished within the DA45 design imposed physical limits of this range.

The trucks' cushion platforms need to be maintained at near 90 degrees to the kingpins. How far from this optimum setup are you willing to skew the cushion platform?
This requirement, combined with the limited amount of pivot pin extension, is what what dictates the "fixed" limits for your range of tweaking the DA45 pivoting angle.
Skewing the cushion platform away from 90 degrees by more than 2 or, at the extreme, 3 degree starts to have a detrimental effect on action smoothness. How few pivot pin threads are you willing to leave engaged in the truck as you extend it out to the max?

So, let's assume that with a max of about 2.5 degree of shift of the trucks pivoting angle you have the ability to alter the performance of the plates to reach. a 42.5 degree pivoting angle. This only brings you roughly 10-12% of the way toward matching the pivoting angle of what a DA10 true speed plate has for a pivoting angle.

This is certainly a detectable difference, but it still leaves the DA45 plate performance a being 88-90% matching the DA45 action that it retains, and only 10-12% shifted in the direction of how a shallower action DA10 performs.

Bottom Line: Using skewing of the truck cushion platform as a way to gain significant changes in a plates turning response profile, is only going to alter plate performance by a limited amount.


-Armadillo
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