Main Discussion Area > Arrows

Spine wt. on arrows

<< < (2/3) > >>

Pappy:
Mechslasher,I have always been confused on that.My spine tester is 26 between the supports
so if I spind them it is at 26 but for a 28in. arrow,Right. If the arrow was actually 26 it would be about 10 lbs. heaver than the spine tester says  and if it was 30 it would be about 10 lbs. lighter.
That is the way I have always done it but a little confussing.Then to make things more interesting if you have a regular wood arrow that flies good at a certain spine then go to shoots or Cain that all goes out the window,you can go much heaver on them.At least 10 or 15 lbs.it seems to me. ???
   Pappy

TRACY:
Clear as mud isn't Pappy :D

Tracy

Mechslasher:
pappy, i'm guessing that when arrow maker's first set up a spine tester standard, 26" is what they went with.  don't know why.  any two pound weight will test the spine of an arrow.  1/2" of deflection equals 52# spine, or is it 51#.

here's my formula for guessing what spine arrow to start with:
-add 5# for every inch over 28" and subtract 5# for every inch under 28".
-subtract 5# for every 1/4" the bow is away from center cut.
-add 5# for every 25gr. over 125gr. for point weight, subtract 5# for every 25gr. under 125gr.

cane and shoots arrows are tapered, so the spine is calculated different for them.  for tapered shoot or cane arrows, i subtract 5-10# spine.  depending on how much taper they have.  the taper is what makes cane arrows so forgiving because when the arrow leaves the string, it's closer to center than at full draw.  this makes them much less critical of spine and release.

Pappy:
Thanks that helps a lot,been doing it for years but still wasn't sure I was right,guess I was pretty close.That is about the way I have figured it except for the points.I knew heaver made them weaker just no guess how much.Thanks. :)
   Pappy

markinengland:
If you do a search for the actual AMO standard for the spine rating of shafts this explained quite well.
This link should give you that information
http://www.archerysearch.com/publications/AmoStandards.pdf
The spine ratings given are for a standard arrow and bow set up comon at the time the standard was written. Obviously not evryone shoots a standard set up. Once you find out what spine rating works for your bow/string/arrow/loose then you know what spine to aim for in the future.
Mark in England

Navigation

[0] Message Index

[#] Next page

[*] Previous page