Which is stiffer

I would be keen to gather your views on which is the stiffer arrow using recurve barebow pulling 36lbs, 28.5 draw length.

Arrow 1 - 31", 700 spine, 80gr points, 11gr pins, same weight vanes and nocks
Arrow 2 - 31", 550 spine, 120gr points, 8gr pins, same weight vanes and nocks

My centre shot setting suggests that arrow 1 is stiffer as arrow 2 tends to land more to the right of arrow 1. Bare shaft testing puts them landing as respective groups. Please let me know what you think. Thanks
 

ArcheryFox

Active member
There is of course the difference between static and dynamic spine to consider which is why different 'tests' for 'stiffness' may yield differing results. In addition to this remember that the arrows will be different diameter (especially if different make - I am assuming they are the same) which will affect the centreshot test.

To answer your original question in my experience stiffness is largely dictated by the shaft, with point weight being only a small fine tuning factor (though you are looking at quite a large change in point weight here). If you want I can run the two setups through archers advantage for you and see what it says.
I'd expect the 550 is stiffer though given shaft makes the most difference in my experience and 550-700 is quite a jump.
 

Mark2

Member
I presume you have the same button setting for each? I must admit I would have assumed the 550 would be stiffer. Not because they are intrinsically so, but I have shot 730 at 28" and 600 at 29.5", both at 36 lb and drawing 29", with 80 gr in the 730 and 120 gr in the 600. The 600s were a little on the stiff side, whereas the 730 were way too weak.
You may want to check your arrow clearances with the different shafts. You can get very misleading results with an arrow that is way off spine, especially if it is catching the bow on the way through. Barebow arrow behavior is not always as predictable as recurve, especially when string walking some distance.
 
Thanks, yes Beiter button set the same, heavy spring and set midway. I'm string walking but using the same crawl for each. Arrow rest is a Gabriel Bidrop and I've both lipstick and foot powder tested them and getting zero interference.
 

Mark2

Member
That would be really helpful. Arrow 1 is a Carbon Express Predator and arrow 2 a Skylon Paragon
Really. The gr/in are nearly equal at (1) 6.45 ans (2) 6.5

However your diameters are (1) 7mm sorry 6.2mmand (2) 4.84mm O/D

So I assume you are adjusting your center shot for each arrow.
 

ArcheryFox

Active member
See below for the results:
AA assumes you shoot a compound, so I had to drop the supposed poundage to 30 to make the results fall in the range.
So this is not saying what is appropriate for your setup, just which is objectively stiffer.
Screenshot 2020-05-25 at 14.34.33.png
Screenshot 2020-05-25 at 14.35.16.png
The 550 is much stiffer, as anticipated.
NB if I raise the poundage up to 36 then the skylons are still seen as stiff for a compound, so I expect very stiff off BBR. For the 36lb setting the Predators go off the scale as weak.
Screenshot 2020-05-25 at 14.35.31.png
 
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ArcheryFox

Active member
Really. The gr/in are nearly equal at (1) 6.45 ans (2) 6.5 O/D

However your diameters are (1) 7mm and (2) 4.84mm O/D

So I assume you are adjusting your center shot for each arrow.
Yeah, this is what I was getting at before.
If you shoot them off the same setup arrow 1 is going to be pointing a fair bit further left (for a RH archer) than arrow 2.
This would (maybe) explain the result that arrow 2 is flying further right.
 

Mark2

Member
But even if you didn't (assuming rt handed) the thinner Carbon ex would lay to the right increasing a tendency for a weaker looking shot. It is most likely down to dynamic spine differences but this is not easy for a manufacturer to specify, although arguably more useful
 

Mark2

Member
Yeah, this is what I was getting at before.
If you shoot them off the same setup arrow 1 is going to be pointing a fair bit further left (for a RH archer) than arrow 2.
This would (maybe) explain the result that arrow 2 is flying further right.
Sorry yes, I agree with you, I m getting my o/d's crossed.
 

ArcheryFox

Active member
Sorry yes, I agree with you, I m getting my o/d's crossed.
:ROFLMAO:
I did also feel whilst writing that it was a bit confusing with too many 'point left's, 'fly right's, 'right handed's etcetc.
A common problem in the world of archery.
 

Mark2

Member
I coudn't agree more. Especially with barebow. They would only lay around 0.75mm to the left compared to the Paragons. Thats 3/4 turn on a button. Not insignificant but I have adjusted way more for less effect.

Michael, You don't say how far apart your bare shafts are from fletched, or what distance you as shooting, although I guess it's around 20yds.
 

KidCurry

Well-known member
AIUK Saviour
I would be keen to gather your views on which is the stiffer arrow using recurve barebow pulling 36lbs, 28.5 draw length.

Arrow 1 - 31", 700 spine, 80gr points, 11gr pins, same weight vanes and nocks
Arrow 2 - 31", 550 spine, 120gr points, 8gr pins, same weight vanes and nocks

My centre shot setting suggests that arrow 1 is stiffer as arrow 2 tends to land more to the right of arrow 1. Bare shaft testing puts them landing as respective groups. Please let me know what you think. Thanks
I would say Arrow 2 is a tad soft at 31" arrow length. Arrow 1 is probably coming out sideways and giving you false feedback. Maybe even taking part of the bow riser with it :) assuming right handed archer
 

ArcheryFox

Active member
Arrow 1 is probably coming out sideways and giving you false feedback. Maybe even taking part of the bow riser with it.
Given the clearance tests were clean it could be a possibility that the arrow is hitting the armguard, kicking out, and giving a false result - this has happened to me before.
You can test by putting some small loops of tape on the armguard and seeing if they get torn off during the shot.
 

Mark2

Member
You could remove the arm guard and measure the depth of the lacerations 😵 wrong emoji, right expression.
I would probably start very close and with bare shaft, work your way back and see how the arrows behave in the target every couple of yards (or metres if you are under 30 years old). That may give a good idea of some really wayward behavior not always easy to see by eye.
 
Thank you all for your suggestions. So the upshot is that the Skylons should be stiffer but react weaker. I'm a bit reluctant to break off some of the point weight to make them stiffer as they should be stiffer if you see what I mean. I rarely hit my arm so I think I can discount that. When setting centre shot I ended up with the arrow so far to the left that I had to discount that as a cause, hence my query. At 10m 20m and 30m they behave the same and the arrow flight looks pretty good. Barebow is of course an element here but I've been very careful to get the string blur in the same place and discounted bad shots.
 

ArcheryFox

Active member
I wouldn't worry about point weight as, as I say, I find the effects to be minimal.
I personally view point weight as a way to tune to my desired momentum/FOC vs. speed rather than stiffness.

At the end of the day I would suggest to shoot whatever is grouping best and giving you the best results. Especially if you're happy that there are no major flaws in your technique. Just because a book or computer says something, doesn't mean it's perfectly true in reality!! I have often shot well with arrows that were slightly 'wrong' in spine. :)

Equipment is important, and I love thinking about it and playing around to understand/experiment/optimise, but I try and keep in the back of my mind the advice I was once given of 'I think you'll get more benefit from going out and shooting than trying to research whether 1 or 3 degree offset is best!'. ;)
 

ArcheryFox

Active member
Also at distances out to 30m (close range) a stiff arrow will behave and group a bit better than a weak one (true for compound, I think it also holds for other bows as based on recovery and bending in flight).

I'd suggest checking out to 50m if you can, but after that just pick one arrow and tune it in.
You could always try and get some video to see how the arrow is flying - it's amazing what modern phones can capture.
You say barebow is an element, but the mechanics of the arrow coming out the bow aren't too different from recurve and I have shot with some shockingly good barebows in my time! 😜
 

Mark2

Member
Personally it probably doesn't matter how they behave comparatively, on a bow that is not tuned for each arrow, as long as you can tune them both in without going to solid/very soft button or very light/stupidly heavy point weights. But you will most likely end up with a very different bow tune for each arrow.
I change between ace 620 and carbon one 600 and have significantly different tuning, although they are the same length and point weight. So I have tuned the carbon ones for 18m with a large string walk on my G2k and the ace 620 for the GMX for longer distances and less extreme anchor.
 
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