Author Topic: Efficiency of Sinew Backed vs Self Bows  (Read 10315 times)

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Offline blindarcher

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Efficiency of Sinew Backed vs Self Bows
« on: July 28, 2019, 09:53:55 pm »
All,

I was wondering if anyone had done a study on expected differences in efficiency one might expect by using sinew versus no sinew on a given bow design.  That is, is there an appreciable improvement in arrow speed of equivalent bows, differing only in that one is sinew backed? Has this difference been quantitatively measured?

Cheers!

Offline sleek

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #1 on: July 28, 2019, 10:12:39 pm »
If its designed for sinew, it will work better with it. If sinew is used to save a self bow, it wont be as good as it was before the sinew.

All that is subject to so many variables, you may never experience any of what I just said to be true.

Hows that for small print?
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Offline SLIMBOB

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #2 on: July 28, 2019, 11:38:03 pm »
Sinew allows you to do things you can’t get away with on a self bow. So...2 identical bows, one sinew backed, one self backed...the sinew backed will be slower, all things equal.  Stress the sinew backed bow to take advantage of the sinew and you change the equation.
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Offline Pat B

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #3 on: July 29, 2019, 02:42:09 am »
2x what both said.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Dances with squirrels

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #4 on: July 29, 2019, 06:46:53 am »
Yep. Close enough. X3
Straight wood may make a better bow, but crooked wood makes a better bowyer

Offline bradsmith2010

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #5 on: July 29, 2019, 04:28:44 pm »
for example if you had a 52 inch stave,, and it was wide enough to get two bows 1 1/4 wide
make one sinew backed and one self bow,,both bendy handle ,,straight tip
draw length 25 inches,,
if you put the right amount of sinew on,, it will hold some reflex and shoot in the 170's
ok now the self bow, even if you heat some reflex in,,most is probably gonna pull out,
but it will shoot hard,, pretty hard at first, but after 1000 shots and being left strung for hunting,, its probably gonna have a little set,, and not shoot as hard as when new,,
ok the sinew bow,, it will probably hold the same profile as new,,and shoot about the same,,as when new,, probably out shooting the self bow sister at this point,,by a little, not so much a deer could tell,, but through the chrono,,
now that being said,, if you had a good 66 inch stave for the self bow,, you could get it to shoot about as hard as the sinew bow,, and it would stabalize and shoot like that from now on,,
so on a short bow the sinew will have an advantage,,but on a longer self bow,, the self bow holds its own,, thats been my experience,, lots of variables, and there are exceptions to everything I said,,
on this site,,, if you say it cant be done, theres somebody doing it,, ;D

I will say I love both sinew bows and self bows,, so I am not that biased,, and love to hunt with both too,, Ok I pretty much love all bows,, (SH)


Offline Del the cat

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #6 on: July 30, 2019, 05:37:58 am »
First you have to define efficiency.
Power output/Power input, but at what arrow weight, draw length etc.

I'd imagine the efficiency is very similar, the difference being the sinew allows you to put in more power due to it allowing more reflex and more draw over a self bow. Of course more power in will give more power out.

Mind if by efficiency you include easiness and speed of manufacture...  ::)
Del
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Offline PEARL DRUMS

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #7 on: July 30, 2019, 03:57:27 pm »
I've done no scientific testing, but I have made a few bows and shot a few bows. In my opinion a short sinewed bow is no faster or zippier than a properly built self bow of equal draw weight. Sinew basically allows a much shorter bow for the a given draw length, its about the only advantage I've noticed. I also believe short bows give us the illusion of speed, cant explain it, but I think we all have shot an extra short bow and thought it was faster than average when really it wasn't.
« Last Edit: July 30, 2019, 05:11:09 pm by PEARL DRUMS/PEARLY/PD/DRUMS »
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Offline Selfbowman

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #8 on: July 30, 2019, 06:16:09 pm »
Spot on Pearl! The Osage selfbow has ruled the distance shooting for some years now. But maybe the great sinew Bowyers have not found the interest. Mike Yancey builds a good looking sinew pyramid bow but I have never seen ones performance. I am curious though. Arvin
Well I'll say!!  Osage is king!!

Offline PatM

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #9 on: July 30, 2019, 07:14:24 pm »
The sinewed Osage bows of the  great days of flight shooting actually did better than the selfbows.  They did better than the bows of today too.

 

Offline bradsmith2010

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #10 on: July 30, 2019, 09:52:25 pm »
Pat do you think that was because of recurving,  design,, or what,, ?

Offline PatM

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #11 on: July 30, 2019, 11:18:12 pm »
All of the features and materials combined.

Offline bradsmith2010

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #12 on: July 31, 2019, 12:49:14 am »
thats very interesting to know,, how would I look that up,,I would like to study that,,

Offline Pat B

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #13 on: July 31, 2019, 02:11:03 am »
...but aren't sinew backed hunting bows vs. sinew backed flight bows apples vs. oranges?
« Last Edit: July 31, 2019, 02:58:05 am by Pat B »
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline sleek

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Re: Efficiency of Sinew Backed vs Self Bows
« Reply #14 on: July 31, 2019, 02:30:49 am »
...but aren't sinew backed bows hunting bows vs. sinew backed flight bows apples vs. oranges?

One shoots a light arrow far, the other a heavy arrow far, both are not the same requirements from a bow design.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others