Thinner shaft....weaker?

[dch0311]

Would an Easton axis shatf spined at 400 be weaker than say a standard shaft like a beman bowhunter at same spine?

[JRY309]

It's not really thinner,it's a smaller diameter but also has a thicker wall.A 400 is the same spine on an Axis as the larger Beman ICS Bowhunter.But being the slightly smaller diameter will move it closer to center then the larger diameter.It may make the Axis seem stiffer due to the closer to center for its dynamic spine.But they have the same static spine of .400.

[Shawn Leonard]

JRY has it right except I would think the Axis would act less stiff as it would not have to go thru as much paradox, the fatter shaft would have to wrap around the riser more than the skinny(may be wrong though) but .400 spine is .400 spine, just remember carbons are spined using 14" centers and trad wood arrows at 13"s on center, so spine a carbon with 13" centers and see how stiff it really is. That is why I never understand why guys want to shoot say a 55/75(.400 spine) out of a 55# trad bow without adding a bunch of weight up front. Sorry for the rant!!! Shawn

[riverrat 2]

I shoot those 400 Axis traditionals out of my Centaur. They do seem stiffer than the 400 spined 5/16 arrows that I use out of my other bows. I have the HIT .75 insert,and a .125 head,and the arrows are cut at 30.5 long. I need a spine tester. I would love to know how much a carbon's spine is affected by every 1/4" you nib one down. But,JRY309 I agree. They do seem stiffer to me as well.

[Bladepeek]

That's where Stu Miller's calculator really shines. Guys will argue all day long whether it works for them at determining the correct arrow for their bow, shooting style, draw length, etc.

However, once you have an arrow that is really set up right for you and your bow, you can put the info in and then change things one at a time, like length, point weight, insert weights and the dynamic spine reading will show you the effect of the change.

Regardless of whether you think it can pick the correct set-up or not, once you have a good setup, it has been 100% reliable for me in making comparisons.

[Shawn Leonard]

Get a spine tester and spine a carbon like a woodie, arrows that were, what was shot off trad bows years ago. They are spined with 14" centers, spine one with 13" centers and see how much that deflection goes up! Also for some reason once carbons get longer than 30.5"s or so the less weight you can shoot up front and I mean by a lot. Still workin on that one. I mean shoot a carbon that is 30"s with say 225 up front, than shoot one that is 31"s with the same amount of weight, just that one inch makes the arrow act way weaker, now cut 1"s off the carbon and make it 29"s, you will be hard pressed to tell the difference. I actually started some more testing today to try and figure this out to make more precise my spine selections for guys with long draws. Shawn

[BWD]

Originally posted by riverrat 2:
I shoot those 400 Axis traditionals out of my Centaur. They do seem stiffer than the 400 spined 5/16 arrows that I use out of my other bows. I have the HIT .75 insert,and a .125 head,and the arrows are cut at 30.5 long.

Could it be due to your Hit inserts being located further back in the shaft, and your 5/16" shafts having the weight located further forward? Seems to work that way for me anyway.

I have a carbon arrow spine tester. It is on a 14"center. There is another difference that should make the two (carbon and wood spine tester) even out. The wood spine tester uses 13" centers and a 2# weight to measure the deflection. The carbon tester uses a 14" center but only a 1.94# weight to measure the deflection. I have always thought that the differnce in the weight would make the readings come out the same, but I have never tested that out?

Bisch

[riverrat 2]

I am going to get a spine tester soon. They cost a bit more than I thought. And BWD,I bet your onto something. And Shawn has me contemplating a few things as well regarding length vs. spine change from full length to cut length. I think that the inserts position way down like that is altering spine more than I realize. Carbons.