Arrow Spine Summary

[The Gopher]

Hey all, i got fed up with trying to figure out all the things that effect the spine of arrows. Here is a summary sheet that i put together so i can keep it all straight. sorry if the pic is too hard to read, PM me with your email address and i can send you the full size copy. or maybe the moderators will allow an exception to the picture size? anyway here it is. thanks, Dan.

 

[The Gopher]

yeah you can't read that at all, PM me for the full size.

[The Gopher]

Factors Effecting Spine for Wooden Arrows


String
•Fast Flight string weakens arrow.
•Increase spine by ~15 lbs when switching from B-50 to FF.

Head Weight
•Heavier head weakens arrow.
•For every 25 grains over 125, increase spine by 5 lbs.

Arrow Length
•Longer arrow weakens arrow.
•For every 2” increase in arrow length, increase spine by 5 lbs.

Centershot
•The more centershot a bow, the stiffer an arrow can be shot from it.
•A self bow with no shelf requires a weaker arrow than a recurve.

Bow Quiver
•Adding a bow quiver stiffens the arrow.
•A bow with bow quiver will require a slightly weaker arrow than without bow quiver.

Feather Size
•Bigger feathers will stiffen an arrow.
•An arrow with flu flu’s will require a slightly weaker spine than an arrow with 4” parabolic.

Crown Dipping
•Crown dipping will stiffen an arrow.
•An arrow that is crown dipped will need to be slightly weaker than un-dipped

String Silencers
•Adding string silencers stiffens arrow.
•A bow with string silencers will require slightly weaker arrow.


Notes: The first 4 factors are the main ones that effect arrow spine, however the last 4 can add up to a point where a weaker arrow is required.


Source: I did not come up with this on my own, it is summarized from “Picking the Correct Arrow Spine for Longbows & Recurves” by Doug Besherse,  http://www.bowhunting.net/traditionalarchery/default.htm.  I hope Doug doesn’t mind, he did such a good job of describing something I had a hard time grasping that I wanted to capture it.