Author Topic: string tension at brace and bow performance  (Read 907 times)

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Offline stuckinthemud

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string tension at brace and bow performance
« on: June 06, 2019, 01:04:51 pm »
Several of my bows have low string tension at brace.  What does that indicate - is the brace height (I use a fistmele) too low, or the bow too long and what, if anything, would tinkering with brace height achieve in terms of performance, would the improvement in pre-loading the bow be off-set by decreasing string angle?

Offline Badger

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Re: string tension at brace and bow performance
« Reply #1 on: June 06, 2019, 01:17:06 pm »
  Your brace height will have little affect on performance. Most likely you have low tension because of high string angles Maybe you are whip tillering or letting the outer limb bend too much. Have you got a braced pic of a bow. Increasing reflex will naturally improve braced tension as well.

Offline DC

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Re: string tension at brace and bow performance
« Reply #2 on: June 06, 2019, 01:50:03 pm »
Set or deflex can cause it too.
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Offline stuckinthemud

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Re: string tension at brace and bow performance
« Reply #3 on: June 07, 2019, 12:49:01 am »
They are about 67" long and draw weight of well below 40# so whip tiller would fit the bill, I guess. I could pike them but I like the way they shoot (lightweight) target arrows.  I was mostly concerned I might be missing a trick or two. Thanks both.

Offline simson

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Re: string tension at brace and bow performance
« Reply #4 on: June 07, 2019, 03:41:30 am »
What wood, what draw length, what design (side profile).
If you use osage, stick bow the bow length is way too long for a 28" draw.

I always like to have very high string tension at brace, the string sound should be a high tone when plicking the string.
The side design (unbraced) has an important influence.

So, to discuss your problem we need the specs (above) and side pics (unbraced, braced, drawn)
Simon
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Online George Tsoukalas

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Re: string tension at brace and bow performance
« Reply #5 on: June 07, 2019, 05:41:22 am »
I usually set the brace height at the lowest at which I achieve good, silent arrow flight. Other than that I don't worry too much about string tension and such. Jawge
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Offline gutpile

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Re: string tension at brace and bow performance
« Reply #6 on: June 07, 2019, 06:01:02 am »
high early tension equals speed and performance... IMO.. when I get that early tension on draw, pluck string and its high pitched .. you done good .. I smile ..gut
to take from nature the materials needed to take from nature the meat needed...they all die from natural causes osage, rivercane, stone points,...

Online SLIMBOB

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Re: string tension at brace and bow performance
« Reply #7 on: June 07, 2019, 06:22:53 am »
Just a quick thought on this....Early string tension is not a goal in and of itself for me.  It is simply the result I get from doing several other things.  Amount of reflex and string angle primarily.  DC mentioned both aspects, whip tiller and set, or more correctly I think, string follow.  As you move the tips farther behind the grip you will lose string tension, all things equal.  As you move those tips farther in front of the grip, you increase it.  String angle is at play as well.  Whip the tips and your string has more leverage on the limb and so the limb bends against the force of the string more easily.  Straighten or recurve the tips and stiffen them and you are pulling at an angle where the string has less leverage.  More tension on the string per brace height inch as a result.  Whip the ends on a bow with some string follow and you compound the issue.
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Online Deerhunter21

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Re: string tension at brace and bow performance
« Reply #8 on: June 09, 2019, 07:55:58 am »
The TBB 1 says the lower the string tension the better the performance. I cant remember why though? I'll look it up in the book. Also in my museum they keep the bows strung with the string they found it with and alot of them have a super low brace hight too.
"Only when the last tree has died and the last river been poisoned and the last fish been caught will we realise we cannot eat money." Cree Native-American Proverb

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Offline PEARL DRUMS/PEARLY/PD/DRUMS

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Re: string tension at brace and bow performance
« Reply #9 on: June 10, 2019, 06:04:02 pm »
If your tips are behind the handle a higher brace is needed. The farther ahead of the grip the tips are the lower you can get away with. Fistmele is a useless way to set a bows brace, I see it used way too often. Lets say you and I both pull pull 28". My hands are huge and yours are small. Should we shoot the same bow with different brace heights as a result of our hand size? No. That is just one reason it doesn't work well. It may be a nice way to quickly gauge a brace height after the bow has been tuned correctly. Maybe your thumb touches or maybe its 1" away, either way you can quickly reference it. The bow you described will shoot best and feel its best at about 7.0"-7.5. Not sure how many millimeters that is :)

 
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Selfbowman

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Re: string tension at brace and bow performance
« Reply #10 on: June 11, 2019, 12:15:52 pm »
Pearl What would be a good brace for 69" 50@28 2" reflex , pyramid. I have been going at 6-61/2 from inside of grip at thumb web. Arvin
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Offline PEARL DRUMS/PEARLY/PD/DRUMS

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Re: string tension at brace and bow performance
« Reply #11 on: June 12, 2019, 04:25:00 am »
Arvy I would say 6.5" must be right since you are a good builder and shooter, you know when a bow is tuned.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Selfbowman

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Re: string tension at brace and bow performance
« Reply #12 on: June 12, 2019, 06:49:51 am »
Ok Pearl but always like your oppinion. Arvin
Well I'll say!!  Osage is king!!

Offline PEARL DRUMS/PEARLY/PD/DRUMS

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Re: string tension at brace and bow performance
« Reply #13 on: June 12, 2019, 08:00:42 am »
That read kind off snotty, not my intentions Arvy. I just know you know what a tuned bow feels like. I do think there are slight differences in a tuned hunting bow and tuned distance/speed bow.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Selfbowman

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Re: string tension at brace and bow performance
« Reply #14 on: June 12, 2019, 10:00:32 am »
New you ment no sarcasm. Arvin
Well I'll say!!  Osage is king!!