spine

[Cyrille]

I recently aquired a number of arrows of various spine weights so that I might determine which spine is the best for my bow. The arrows are rear nocked and fletched, 32 1/2 " in length, no points installed.
 Two questions:
1. Should I leave the arrows at the 32 1/2 " length when I "bare shaft" test them, or cut them
to my draw length and then test them, with the point weight I would like to use?

2. at what distance from the "target" should I conduct the test, 15, 20 feet, yards or somewhere in between?

[Curtis Haden]

Cyrille,

Here's some good information to get you started:

 http://www.bowmaker.net/index2.htm

(may have to click on the "bow tuning" link at top of the page)

There's a good spine chart there also to get you close if you're shooting aluminum or wood.

If I'm shooting an unfamiliar bow/arrow combination, I like to start fairly close and work my way back.  I usually end up bare shafting out to about 20 or 25 yards.  I don't shoot consistently enough to go much farther than that, but it's far enough to get you in the ball park for the right arrow.

[McDave]

I'm a little confused by your post.  You say your arrows are "rear nocked and fletched."  Then you go on to say that you want to "bare shaft test" them.  Bare shaft means an unfletched arrow, which is the source of my confusion.  We use an unfletched arrow because it is hard to tell anything when we shoot a fletched arrow.

When we bare shaft test a wood or aluminum arrow, we generally start with an arrow a little longer than we think we are going to use.  For example, I like to shoot a 29" arrow, so I might start with a 30" arrow.  I would never shoot a 32 1/2" arrow, so there wouldn't be any point in my testing at that length.  If we are bare shaft testing a carbon arrow, we can start at the length we desire, since we adjust those with internal weights (provided we're shooting carbons that allow that kind of adjustment).

Then we go through our test shots, as is discussed in the link in the post above or similar methods, until we decide if the bare shaft is too stiff or too weak.  If it is too stiff, we can try a heavier point or go on to the next weaker spined bare shaft.  If it is too weak, we can try a lighter point or begin trimming 1/2" or so off the shaft until we get an arrow that flies straight (or until we run out of arrow to trim), or we can go on to the next stiffer spined bare shaft.

We hope to end up with a bare shaft that flies straight, or just slightly weak (since the fletching will stiffen the arrow a tad), and then we will make our fletched arrows with the same length and point weight as the bare shafts.  I save all my bare shafts, as I am constantly referring back to them.  Almost anything you do to the bow: change brace height, nocking point, string silencers, shelf pad, etc., will have some effect on the flight of the bare shaft.  Or if you change your shooting style, that will have some effect, and if you change enough things, you may want to change your arrow at some point.

[Cyrille]

That had me puzzled too. I know/knew that bare shaft testing meant just that, testing a bare shaft. Yet when I received the "test kit" it contained arrows of various spine weights that were already nocked and fletched. Well I figured that the company who sells these test kits must know something I don't. After all they are a reputable archery supplier and are advertised on this site. Perhaps I used the wrong term. What I would like to find out is which spine weight shoots best from my 58# horsebow which, if you don't know about horsebows is of recurve design. Can the best arrow spine weight for a given bow be determined by shooting an already nocked and fletched arrow?

[McDave]

I think you can tell something by shooting a fletched arrow; a lot of people don't ever bother to bare shaft test.  But I'll bet they can't tell if a 28 1/2" arrow shoots better in their bow than a 29" arrow.  They probably say, "Who cares? if they both look the same when shot with feathers, that's good enough!"

If you're testing various fletched arrows, you just have to make sure your nock point is high enough so that there is no bounce off the shelf, and then look at the arrow flight and pick the one with the least wobbles.

[Cyrille]

The bow has no shelf, I shoot off the knuckle of my1st finger left hand.

[McDave]

People use bare shaft tuning to tell if their nock point is 1/8" high or low, etc.  But with the natural variation you would have shooting off your knuckle, I'm not sure that information would be all that useful to you.  Do you use a string nock?  Normally, we set our string nocks anywhere from 3/8 - 5/8" above square (measured to the bottom of the string nock, if you nock below the string nock), so that the arrow will clear the shelf without deflecting off of it.  We measure this with a bow square resting on the arrow shelf, and I suppose you could do the same thing with the bow square resting on your knuckle, although the measurement would be approximate.  With no arrow shelf, I would tend to go to the high side rather than the low side of this range since arrows correct rather well to being shot nock high, and it would also make it easier on your knuckles, I suppose.

As far as spine is concerned, with no bare shaft tuning, based on my general knowledge of recurves, I would be inclined to cut my arrows 1" longer than my draw length and just try them with my bow until I found the one that seems to fly the best.  I might also try them with heavier or lighter points and see if that helps.

Hopefully, you will find someone more experienced in horse bows than I am who could give you better information.