August 30th, 2010, 10:26 PM
Arrow spine charts from Easton
Do the arrow spine charts seem off from easton?
Just Livin the Dream
August 30th, 2010, 11:17 PM
I suggest trying a search on this topic. It has been hashed over more than once.
I feel like they are pretty much on. The charts however are not gospel and only provide a close starting point. It is more likely that something in the archers form (usually in the release) is off. The charts get you close, but simply can't account for variations in form that affect the dynamic spine of the arrow.
There however are others on this board that totally disagree with me on this point and believe the charts are way off and read too stiff.
August 30th, 2010, 11:18 PM
i think they are on for the most part
August 31st, 2010, 12:01 AM
Thankyou for the repllies!
Just Livin the Dream
August 31st, 2010, 10:08 AM
I personally find them atleast a spine too weak for me, with both ACE's and X10's. Shooting 1260+ FITA's (recurve).
August 31st, 2010, 12:21 PM
I think too, that it matters where you are on the chart.
If you (like me) find yourself to any of the extremes i.e. low/high poundage and/or short/long arrows the charts are of less use.
As and example...
When I shot competively, I was at #51 and 32" arrwow, it was hard to find an arrow stiff enogh (ACE 370's too weak)
Now I'm old and shooting #29 and 31.5" arrow, it's hard to find an arrow that weak enough (2016 are too stiff)
As with anything YMMV.
This is a good place to ask and compare with others as far as draw weight/length arrow selection.
August 31st, 2010, 12:49 PM
to use the chart properly make sure you use the adjusted draw weight calculation too. Easton has it available for download on their site. Depending on your draw length, poundage, arrow length, point weight, and cam type the choices for your bow will change. The best system for finding a really good starting point is with some sort of arrow selection software like Archer's Advantage or TAP.
August 31st, 2010, 02:57 PM
My experience with ACE and X-10 is that they are one size too stiff, at #38 and @28 inch draw. With aluminum arrows I think it is three spines too stiff, at least that's been my experience and I've got the shafts too prove it!
August 31st, 2010, 04:39 PM
I did have athletes with 10 f/sec variation (1100 averege) and some with less then 1.5 f/sec (1230 over) and this is the level of a dynamic technic.
So the variation of your technic have an effect on the chart so an experience coach is normally able to help with that chart.
But as Spangler mension, it's only provide a close starting point.
August 31st, 2010, 10:07 PM
A little heads up. You have to know your bow for the charts. (I can really only speak from the recurve side of things)
While every HOYT I've ever owned I've had to go in size or a little stiffer from the spine charts (I prefer stiff arrows... no jokes please)... with the RX, because it's more efficiant with the spine, I have to go on the weaker side of the charts. My arrows ARE flying faster out of the RX, but the tune on the RX is crazy stiff compared to the GMX (same arrows, same limb weight, etc). I know it sounds crazy, but I'm not the only one experiencing this with the RX.
I'm sure the guru engineers can explain it in technical terms, but from a practical standpoint... Easton spine charts are pretty darn good, but with the RX, definately consider the weaker shaft.
GMX- 30 inch groove to point (I shoot a Cavalier Extended clicker - 1 inch in front of the riser). 28 inch to center of plunger. 120g points. 68 inch bow. 40lb 990s cranked down to 42-44 lbs. 550 X10s tune perfectly for me. 520 ACEs. I shoot 2312s for indoor but leave them almost full length and load up the point.
RX - same set up. Bare shaft is 1 1/2 ft stiff at 20 meters. Arrows actually FLY 4 fps faster. Indoors, I had to add point weight. Think I went from 160g to 185g, but I honestly don't remember.
Last edited by KJarchery; August 31st, 2010 at 10:15 PM.
Reason: more info
August 31st, 2010, 10:42 PM
there are so many variables
example, Last year I was shooting a GMX with 40 pound 900 Hoyt limbs (25" riser, med limbs). 28.5 inch (nock to start of point) 600 X10s-very good tune. Now, RX, 27 riser with 40 pound F4 mediums and the 600s are several rings stiff at 30M (on a 122) I know that I lost some weight with the longer riser but the holding weight is within a pound due to cranking the limbs a bit
two years ago a 550X10 cut to the same length shot out of a 25" hoyt riser with 42 Medium 900 limbs were very stiff
now my student Sean Curtin was using them on the same basic set up (he was using 42 Medium M1) and they tuned perfectly. We have the same draw length. When he went to 44 pound 990s on his aerotech the were 4 rings weak-so we cut them down a half inch and went down 20 grains on the point weight-still weak
different people get different results even if holding the same weight and having the same DL
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