2315 spine?

[Jeff Sample]

Can someone tell me what the spine is for a 2315 aluminum arrow?

Thanks!

[bigcountry]

Spine is 0.340" AMO

[WESTBROOK]

Bigcountry is right, I think that what they use for the 340 GG shafts now, 300 is a 2317.

Eric

[Jeff Sample]

OK, but what does that translate into pounds? I'm trying to figure out what spine wood shafts to order based on the fact that 2315s shoot well out of my bow. I seem to remember that they are in the range of 110#.

[bigcountry]

According to Arrowsbykelly charts, a 2219 is close to teh same AMO spine as a 2315spine.  And according to his chart, yourlooking at 95#

 http://www.arrowsbykelly.com/Spine_Charts.html

[Jeff Sample]

Thanks. 2219s are clearly weaker in spine, based on comparison of them to 2315s shot out of my bow. Unfortunately, 2315s are not on Kelly's chart.

[Jeff Sample]

ttt

[Cupcake]

Jeff,
The spine of a 2315 is 92.1 lb.  For any aluminum or carbon shaft the spine can be calculated by dividing 31.5 by the deflection.  For the 2315 deflection is .342" so: 31.5/.342 = 92.1 lb.

This calculation is derived from beam deflection theory that I used to translate between wood spine test methods and the aluminum/carbon methods.

I have verified the calculations with measurements.
Kevin

[Jeff Sample]

Thanks Kevin! I just had another TradGang member PM me with the same spine. I would have thought it was higher than the 2219, as the 2219s are very clearly weaker than 2315s shot out of my bow (same length, tip weight, etc). I guess the heavier weight of the 2219, coupled with its smaller diameter that brings it closer to center on my bow in effect makes it a weaker-spined shaft. Also, my 90-94# POC arrows (same length and tip weight) show a bit weak; these are 23/64" diameter like the 2315s, but heavier. Looks like shaft weight contributes significantly to overall/dynamic spine.

Thanks all!