Paper Tuning vs. Archers Paradox?

[Mr. fingers]

I bare shaft through paper til  i get a perfect bullet  then a fletched arrow through paper for a perfect billet with 3 neat fletch tears. 6ft out too. 30 ft.
Then I will double check a bare shaft with my fletched arrows out to 20-25 yds.  BH and field point usually hit right together.
If not its a small amount of tweaking nock point hight or brace hight. To get it dialed in.
An arrow saw is a must

[DaveT1963]

So is your arrow proper spine if it hits where you are looking at 20 yards but flies pretty much tail left (for right handed shooters)?  I've also noticed that targets can straighten out the shafts as they hit and that your release can give you pretty mixed results?  I've just gotten to the point that I shoot broadheads all the time now and if they hit where I am looking without crazy flight problems they are good enough.  I use 3 four inch feathers and some pretty big Simmons so I thought they were spined properly.  SO I decided to test them, I striped off the fletching, replaces my broadhead with a matching field point and shot at a snad bank... about 15 yards down range they take a hard left and nose dive.  I tried to resolve this with bareshafting and I came to the conclusion that with the high FOC I am using that I will always get a tail left and down when bareshafting - am I wrong?

[KSdan]

DaveT-  Nock kicking left- point heading right means weak spine (for right hand shooter.)  Nock high- point heading down means high nock point. Even with EFOC you may be surprised how much you can adjust that tweaking nock pt. and brace ht.

Dan in KS

[DaveT1963]

Lowering brace height weakens spine and raising it increases spine - is this correct?

[KSdan]

How I remember: lower brace = more power stroke (arrow on string longer).  higher brace ht. = less power stroke  (arrow off string sooner).  

So all other things being equal- technically- lower brace ht. may require stiffer spine.  Higher brace may allow weaker spine.

Others may need to correct me.  How I think of it though. . .  

Dan in KS

[mahantango]

Actually, it's just the opposite. A lower brace height requires a lighter spine because it increases the angle of the arrow away from center as the string approaches the riser.

[Dale in Pa]

KSdan, actually it's the opposite,not because of powerstroke though. It has to do with the angle of departure of the shaft at release.

Since your arrow always points somewhat away from the shelf when viewed from behind,the lower the brace,the more severe the angle is. With a higher brace,the arrow is pointed closer to center. The same as changing center cut on your riser.

[DaveT1963]

So if my arrows are currently weak I raise the brace height?

[Stephengiles]

If weak,lower b.h. If stiff raise b.h.

[KSdan]

I am sure open to learning and correction.  I hear you guys on angle- but I thought the energy the bow delivered to the shaft had a lot to do with power stroke. If I check fps based on contrasting brace hts I will see a direct correlation.  Higher brace is less energy = slower arrow = shaft acts stiffer.  Lower brace is increased energy = faster arrow = shaft acts weaker.  So- one way to fine-tune a slightly weak shaft is either to increase brace ht or slow the string down (more strands, add another set of silencers, or go to more pliable string material,ie dacron).  This is also why you can quiet a bow down this way though you are decreasing some potential performance.      

I know the FITA Manual agrees with me on brace ht. adjustment.

Perhaps you guys are suggesting the angle is a stronger variable than the power stroke. I wonder if style of bow has any bearing on this. Has me curious???

Sorry if I messed anyone up

Dan in KS

[ironmike]

no, the low brace height is a longer string,the longer string reduces bow poundage overall.so longer stroke,lower spiner because of lower draw weight.(it will shoot faster however because of the longer stroke) a higher brace hight make for increased draw weight, therefor increase in arrow spine is  required ,shorter string, shorter stroke, a bit slower...so,with a given arrow,you simply adjust brace hight up or down to move you poa right or left(for right handed shooters.

[LB_hntr]

This is brace hieght thing is interesting. I have always believed as Dan has. That the lower brace equals longer power stroke needing stiffer spine. higher brace equals smaller powerstroke and weaker spine needed.

I too would love any brace height gurus that can verify this correct or false.

[KSdan]

I am still watching this. . .    :confused:  

Review the FITA Manual! If some of you are correct that lower brace height means less energy you need to correct the International Archery community.    

[DaveT1963]

I've always moved my arrow impact to the right (weakening shaft) by lowering brace height and stiffening a shaft impacting more left by raising brace height?  Am I seeing this wrong?  I've already been told the arrows paradox always starts as it bends around the riser.... the longer the string stays in contact with the arrow the more it will initially bend around the riser?

[DaveT1963]

I suppose on a true center cut bow the opposite might be true?

[Stephengiles]

I believe  what they're trying to say is that even though you have a shorter power stroke,you have more weight initially bending the arrow. But if it works differently with your bow I wouldn't worry.

[KSdan]

Originally posted by DaveT1963:
I've always moved my arrow impact to the right (weakening shaft) by lowering brace height and stiffening a shaft impacting more left by raising brace height?  Am I seeing this wrong?  I've already been told the arrows paradox always starts as it bends around the riser.... the longer the string stays in contact with the arrow the more it will initially bend around the riser?

Yes. This is how I see it regards brace ht. Been tuning the bows I shoot this way for 3 decades. As noted: perhaps some bow styles react differently though.  That would be new to me.

FITA Manual pg 10:  "Decrease brace ht- Be careful here as this gives a longer power stroke thus makes the arrow seam weaker.  Increase brace ht- Be careful here as this gives shorter power stroke thus makes the arrow seem stiffer."

[Prairie Drifter]

For me if the arrow is stiff, raise the brace height, if weak lower brace. Also been doing this for decades.

On most bows changing the brace enough to shift the spine, does not change the poundage all that much. If one needs a drastic brace change the shaft spine is way off and a different spined shaft would be a better fix.  The old rule was that a lighter spined arrow would have a better timed paradox with a lower brace and a stiff arrow would not skid off the shelf and move to the left with a right hand bow as bad with a higher brace.
If we watch carefully, the Howard Hill short shows that initial bend of the arrow at release bends into the bow.  This is because the arrow is pointing to the left and resistance of the weight of the arrow is reacting to the forward drive of the bow.  As some of the arrow gives and extends beyond the bow, then the arrows shows the outward bend.  Well the arrow is still on the string, it has two bends going at once for a time.  I know the old rule works the same for today's Hill style bows and wood arrow that are cut to the proper length and the same holds aluminum shafts.  With a bow that is cut inside of center and with a lot of shaft beyond the bow, and with a lot of foc, any number of variables can come into play.

[olddogrib]

I've just been enjoying my popcorn and watching this one because every time this question has come up the debate has honestly been about 50% defending both sides.  I certainly don't know the answer, but obviously somebody's wrong.  I would offer a bit of clarification for those having trouble understanding the opposing argument to the "power-strokers".  Their point is that arrow spine "is what it is" and lower brace height logically requires the nock to remain on the string slightly longer and release closer to the riser, thereby reducing the "window"(for lack of a better term)that paradox can occur or conversely increasing the amount of bending required for the arrow to get around the riser to a comparable point due to the later release from the string) If this is true a given spine would act stiffer.  I have no dog in this fight...my dog is a lover...just ask my leg!