short bow brace height

[feral]

I have made a 48 inch Osage bow, with two layers of kangaroo sinew. Just into final tillering. So far so good.
I have quite a few short Osage staves and this was a bit of an experiment.
So, anyway, can anyone tell me the best way to judge brace height?
I am looking at about 4 inches but I wonder if there was a precedent  with the shorter bows?
Cheers

[bassman211]

With a sinew backed Osage bow that length I am comfortable shooting it with a 5 inch brace. With shorter bows a little less ,and with longer short bows a little more. JME

[bassman211]

The natives of north America shot short brace height bows, because of there pinch finger style of shooting. They pushed as much with there bow hand until the bow  would pull the string ,and arrow from the pinch finger hand, which prevented breakage .  Quote by Jim Hamm.

[feral]

Thanks
After the tiller process, I sought of settled on a 5 inch brace. It seems to suit the bow.
It is about 50 at 24 but I can't pull it that far even though I shoot a 55 long bow regularly.
It seems to get to 22 inch about 30lb then just release the arrow.
But I am really happy with it.
thanks

[superdav95]

Ya you might be hitting a wall there at 22”.  I’ve found this with some of my shorter bows too.  When shooting them I stay on target and let the fingers release when it feels right.  Very different then shooting trad or long bow.  I’m no expert on shooting short bows but just been my experience with my own.  I’ll get used to the feel of the tension in my hooks in my fingers at 50lbs and then pick up another bow like a shorty and find that my release just happens.  I think what’s happening is the sudden increase of draw weight at a set draw length or a wall causes the release.  I find with these bows I draw slowly and stay on target the entire time and snap release the arrow by feel.  Sounds a little chaotic perhaps but one can get fairly accurate with some practice.  I have to really practice this to get any consistent accuracy as I have a very long draw under normal long bow or trad bow shooting.  Just my 2 cents.   

[Woodbear]

Regarding brace height, for selfbows, I generally design the bow for a brace height that is close to 10% of the bow length. I measure both the brace height and draw length from the bow back, for convenience in determining the active length of draw. This gives a strain at brace height that is about 40% of the strain at full draw. It is generally enough that string slap on the wrist is not bad (i.e. I do not notice it). Perhaps this is just an appearance thing, it just "looks right".

It does bring up the question of tuning the bow for arrow flight. If you made the bow for a particular brace height, is there still room to "tune" for arrow flight?

Your draw weight and distance numbers look odd to me: you have a brace at 5"(0#), 30# at 22", and 50# at 24". That is 30# in ~17"(1.8#per inch), and then another 20# in the last 2 "(10# per inch). I can see why you might release at a particular weight (by feel) rather than at a particular draw length. So long as you can be consistent, it seems like a legitimate way to shoot a short bow.

Dave

[feral]

thanks all.
It does release by itself at 22 inches. So I will go with that.

[bassman211]

Just recently I made a series of 4 50 inch Osage bows. In the 35 to 40 lb range. All have some reflex. First 3 are ok though I had to patch 1 that lifted a splinter behind a knot on the bows back. The 4th one was a clean piece of Osage that was a nice bow until I tried adding more reflex with a form, and belly heat treat after I had it tillered nice at 23 inches with no reflex, but no set either.. I put to much reflex in it, and right at 23 inches it blew on the top limb. It was the nicest stave of all of them. I just pushed it to far.