arrow clearance issues

[Tuck]

GGC

I do not know what TAP is

Easton spine calc gives 520 ish for 45# 30" dropping to 470 ish for 46#

it is usually regarded as good to go for a SLIGHTLY stiffer arrow.

In my book at 45# that means 470, before you go any stiffer PLEASE try some as you could be trying to tune beyond capability.

430 COULD be the right answer but please check befor you commit £200


Dave

[Shirt]

470 is wrong. I've got a virtually identical setup, and the next set of arrows I buy will be 430s because my button is wound up extremely stiff (arrows acting weak).

TAP - The Archery Program. Like Archers Advantage, only a bit different.

[Tuck]

Originally Posted by Shirt

470 is wrong. I've got a virtually identical setup, and the next set of arrows I buy will be 430s because my button is wound up extremely stiff (arrows acting weak).

TAP - The Archery Program. Like Archers Advantage, only a bit different.

I am NOT saying that 430 is wrong - it MIGHT be right depending on many factors - loose, actual weighed weight, string strands etc....

BUT you cannot say that 470 is WRONG as you do not know all these factors!

USUALLY the ACE charts SEEM to be 1- 1.5 spines too weak with modern equipment so a 470 OR 430 COULD tune - checking is the only resolution.

Dave

[Munsterman]

I must admit my button is wound right in too. Come to think of it, it should have given me the info I was looking for i.e. the arrow was too weak

[Rik]

Out of idle interest I ran some basic figures through the old Easton Arrow Flight simulator with a 30inch shaft length, 68inch bow and 110gr points...

It doesn't do Navs specifically (they didn't exist back then), but the results for ACEs and X10s are usually fairly applicable.

Assuming 45# draw weight:
430 - 104% (slightly stiff)
470 - 94% (slightly weak)
520 - 85% (weak)

Assuming 46# draw weight:
430 - 102% (slightly stiff)
470 - 92% (on the weak side)
520 - (out of range - too weak)

Assuming 44# draw weight:
430 - 106% (on the stiff side)
470 - 96% (more or less dead on)
520 - 87% (weak)

Now the assessment of stiff/weak is based on the assumption (which appeared correct at the time) that the EAFS recommended shafts which were a little stiff, usually. That may be an incorrect assumption with faster limbs. What the figures *do* illustrate is that the actual draw weight might be fairly critical. The only way to determine this is with a good set of calibrated scales. Note - not the ones that the average club archer (or shop) has knocking around, unless you trust them to have been checked against test weights recently.

[Shirt]

Key point in Rik's post - faster limbs. I went from Vectors (68", 44# at 30") to G3s (70", initially set at 44# at 30". Same scales used on same day to check and set poundage, so while it might not have been 44# it was at least the same).
Bareshaft XX75 2213 (30" arrow, 100 grain point, 3 x 4" vanes)went from middle of group at 18m to approx four feet to the right (weak side). Similar effect was noted with ACE 470, (30" arrow, 100 grain point, 3 x 1.7" vanes) although it was only about two and a half feet to the right.

Now, the 70" limbs should be slower because of increased limb mass? But hey, it turns out they're quicker, or at least cause the arrow to believe that they are and thus the arrow acts whippier.

Logic: G3s, as many current top of the line limbs, are quicker than many previous generations. Thus software written for the OLD generation (EAFS, TAP, AA, and pretty much everything) will recommend a weaker spine than will shoot comfortably. This includes the Easton spine tables, which have always had a disclaimer of being a "guide" rather than gospel and which lots of people have found to be a bit off by a spine or two.

Summary: I think 470s out of this setup will react fairly whippy, and may be on the borderline of "bloody nightmare to tune".