Arrow spine questions..

[Roy from Pa]

OK, I buy full length shafts, say 31 inches long and they are spined 45 - 50. But on the Ace spine checker the supports are spaced 26 inches apart. I know if you cut an arrow shorter it increases in spine. But yet on the checker if I cut 3 inches off the full length shaft, they still read the same as before I cut them. As I feel they should. So my selfbow is 46 pounds at my draw of 26.5 inches. But while bare shaft testing, I have to reduce the arrow spine to about 36 pounds to get them to fly correctly. Am I missing something? Thanks Roy

[Hot Hap]

I would doubt that your selfbow is anywhere near cut to center, that would require a lighter spine arrow. Hap

[poekoelan]

Yes Roy. There are two kinds of spine. Static spine and dynamic spine. What you read on a spine tester is static spine. This won't change whether the shaft is 28" or 32". It will read the same.

But then there is dynamic spine. This is how your arrow "acts" when it is shot. For instance...a 28" arrow that reads 52lbs on your tester may act like a 52lb arrow when shot. But a 30" that also spines at 52 will act weaker when shot, but it will still read 52lbs on your spine tester. A heavier than normal point will also make them act weaker.

But it sounds to me like arrows are already quite long. Sounds like you should try some shafts that are spined 40 / 45 and leave them long and see how they fly. And if they still seem to stiff, use some heavier points.

I shoot self bows too. I've never tried bare shaft tuning, but some people believe that it can be very difficult to do with selfbows because of the degree of noncentershot for lack of a better word. The farther you are from centershot, the more critical perfect form becomes when bare shaft tuning. At least that's what I've been told. In other words, it can be very difficult to get a good read on spine. But like I said, I've never tried it.

Good luck. Keep me posted on how well it works for you. I just may give it a try.

Austin

[Roy from Pa]

Thanks Poekoelan, bow is real close to center shot. I have bare shaft tested many times and it does work well. Guess I was having one of them senior moments thinking about the spine:)
 

[Art B]

How much handle are you shooting around Roy? You got your shafts rear tapered? What kind of wood shafts are you using? Never had any luck bare shaft shooting a selfbow myself. Arrows will probably be in to much paradox to really get an accurate reading. Bet if you make your arrows 28" BOP at 45# and using 125/145 gr point with rear nock taper using shield cut feathers that they'll tune right in. Wish you luck though.-ART B

[Coop]

BBO's aren't selfbow's ya old phart  

[Roy from Pa]

Ok Coop, a BBO close to center shot, ya happy?  

Art I'd say the bow is maybe 1/8th inch from being center shot, sitka spruce arrows, no taper. I have had good results bare shaft testing it. That is how the arrows got down to 36 pounds.. Ya, I know adding more weight reduces spine too.

[Art B]

That rear taper really helps Roy. Give one a try. You're shooting about the same weight bows that I am but more center shot. My arrow passes are between 3/8-1/2" off center and my wood arrows are spined 50# @ 28" and fly very clean. But then again my draw length is shorter then yours so that helps me out in one respect.-ART B

[John3]

I know that styles and bows are different. I can say that EVERY longbow I've ever owned "liked" an arrow spined at least 5-10#'s lighter than the draw weight. This is from selfbows to modern glass longbows.

John III

[Roy from Pa]

Ok thanks guys.

[Shawn Leonard]

Roy, for every inch over 28"s ya lose 5#s in spine with woood. If ya want to reduce a 45-50 to around 36-37#s than leave it 30"s long. If ya want a shorter arrow get some 40-45# woodies and leave them 29"s long. Shawn

[Roy from Pa]

Thanks Shawn.

[Coop]

Yep, lol

You know I was only messing with ya bro.

[Roy from Pa]

Ya I know Coop:)