# Is there anything bad about shooting a stiff arrow?



## ATB

*Overspined?*

Arrow flight
I am no bow tech expert, but I just went to a heavier arrow for hunting this year. I am having a overspined issue the flight of the arrow is ugly it fishtails right. At short distances it hits where I aim, but at 25 to 30 yards or more the spacing gets a little sloppy. I need to increase broadhead weight or increase draw weight to make up for the heavier spined arrow. This is not the best link I have seen discussing flight with over or underspined arrows and tuning but it may help.
http://www.skookumarchers.com/Archery Library/Paper_tuning.htm

Good luck


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## Deezlin

Basically, if you are not too overspined and are a release shooter, you will see larger groupings at longer distances. But, the plus side is you will have very good groupings at close distances. Now, if it get too over spined, it could get very release critical.

With weak spined shaft you will see the opposite. This is pointed out in the Easton Tuning Guide. Because finger shooter have more release variation they need to have properly spined arrows for as much forgiviness as possible. Also, they use larger feathers for better control of the arrow and for forgiviness from fletching contact if they have a bad release.

Release shooters will also get the best grouping and the most forgiviiness with properly spined arrows. They just can get away with a little more. A stiff arrow also aids the control of broad head flight.


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## Zen Archery

also understand that easton charts are eastons charts. throughout the years they will change their opinions on what they believe you should be shooting. my theory if it aint borke don't fix it. according to easton im overspinned but when im putting the 1st arrow on the spots at 20 30 40 yds what differance does it make that your arrow is overspinned.


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## lwilt

Zen Archery said:


> also understand that easton charts are eastons charts. throughout the years they will change their opinions on what they believe you should be shooting. my theory if it aint borke don't fix it. according to easton im overspinned but when im putting the 1st arrow on the spots at 20 30 40 yds what differance does it make that your arrow is overspinned.


It wont make any diff. unless you see a monster buck at 60 or 70 yards. Also please note, many people are good at these yardages and longer. I personally know a guy that killed a buck laying down at 100 yards and he told me about some gorilla shooters in Arizona that killed a buck at 127 yards. If your bow is tuned and you have correctly spined arrows they will shoot straight forever, but it takes lots of practice and I mean lots.


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## Zen Archery

lwilt said:


> It wont make any diff. unless you see a monster buck at 60 or 70 yards. Also please note, many people are good at these yardages and longer. I personally know a guy that killed a buck laying down at 100 yards and he told me about some gorilla shooters in Arizona that killed a buck at 127 yards. If your bow is tuned and you have correctly spined arrows they will shoot straight forever, but it takes lots of practice and I mean lots.


90% of archers hunt in closed terrain with the average kill range being less than 25 yds. for the 10% who do hunt in open terrain spine and f.o.c. is more of an issue.

still doesnt change the fact that Easton will change their spine chart every couple of years.


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## Deezlin

Zen Archery said:


> 90% of archers hunt in closed terrain with the average kill range being less than 25 yds. for the 10% who do hunt in open terrain spine and f.o.c. is more of an issue.
> 
> still doesnt change the fact that Easton will change their spine chart every couple of years.


I agree with you to a point. Yes, it it for the average short range hunter good to be overspined as long as it doesn't get stupid. I mean like a guy with a 60 pound bow, shooting a 26" 7595. He doesn't need it and it will hurt his accuracy if he uses are release or not. Then as has already been mention is the longer distance shooting done in open country. Here, a properly spined arrow would be the best choice.

I am with you on our type of hunting. Ohio is very thick in the majority of area I hunt. A shot beyond 30 yards would be very rare for me. As far as Easton changing their charts, I personally, hope they keep it up. They have new designs and manufacturing procedures which may change their products some. Also, the bow keep changing. A hard cam of yesteryear, does not compare to a very, very hard cam of today.


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## hoyteaston

Right On To Deezlin! IF Easton didn't change they're charts that would mean that ALL of the bow manufacturers and ALL of the bow string manufacturers have wasted MILLIONS on design and development making better, and more efficient equipment for us to enjoy. simply put, todays equipment is BETTER and more efficient than yesterdays. Why else would anyone shell out $700 or more for our bows?


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## lwilt

Deezlin said:


> I agree with you to a point. Yes, it it for the average short range hunter good to be overspined as long as it doesn't get stupid. I mean like a guy with a 60 pound bow, shooting a 26" 7595. He doesn't need it and it will hurt his accuracy if he uses are release or not. Then as has already been mention is the longer distance shooting done in open country. Here, a properly spined arrow would be the best choice.
> 
> I am with you on our type of hunting. Ohio is very thick in the majority of area I hunt. A shot beyond 30 yards would be very rare for me. As far as Easton changing their charts, I personally, hope they keep it up. They have new designs and manufacturing procedures which may change their products some. Also, the bow keep changing. A hard cam of yesteryear, does not compare to a very, very hard cam of today.


 How do you say that a properly spined arrow is good for shooting in open country. But not up close, 30 or less yards. I agree with you up to a point. I do shoot at long distances, 40+ yards, if I have to. I also shoot at short yardages. A properly spined arrow will do both. The thing about arrow spine, it is the single most important thing about shooting a bow! That is, if your bow is tuned correctly. An underspined arrow will start shooting to the right of center the further you move back. Same with overspined only it will shoot left. The MAIN thing is that, over or under spined the arrow is not going STRAIGHT into the target. On overspined the point hits first but the arrow is really going in like this /, on underspined like this \ , so its isn't getting good penetration like an arrow going straight in. In other words the arrows are not going to go straight in unless they are correctly spined, where you will get the best penetration. The charts are just a starting point, thats why they conflict sometimes. All of the different technology doesn't mean that much, after all bows have been around a long time and now or then the arrows had to have the correct spine to shoot straight. The two things to determine the correct spine is DRAW WEIGHT and HOLDING WEIGHT. Thats it. Tell you what, I shoot a bow that has a draw weight of 57# with a 65% let off. What arrow spine should I be shooting. Now look on the charts and tell me. What I am shooting is a beeman carbon hunter .570-15 with 4" feathers and 75gn fieldpoints, or 75gn mech. broadhead. These arrows shoot straight at all distances. So maybe you can tell me what the chart says I should be shooting as I dont have access to one. PS, I wouldn't change anyway as I'm already shooting the correct spined arrow which I measured on a spine tester. Good Luck with your shooting.


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## Corsair

I do not really understand the issue of spine with *compound bows*.

I understand why one needs correctly spined arrows with a recurve or a long bow - the arrow has to bend around the riser and a finger release makes the string move sideways on release and therefore the correctly spined arrow will allow bending to compensate for these factors and enable the arrow to recover quickly after clearing the riser. Similarly, when shooting a compound bow using fingers for release.

But with a compound bow - *when using a release aid *- I do NOT understand why one needs the arrow to bend at all.

The arrow doesn't have to bend around the riser, because you are using a release aid, string travel is free of any sideways movement, the arrow rest is sprung, or drop away or non existant (as is the case of the air rest), so please explain to me exactly what benefit is gained by having the arrow bend in these circumstances.

When an arrow bends, it loses some of its energy to the bending process. This detracts somewhat from speed. In addition, bending increases the drag forces on an arrow. The stiffer the arrow, the less the bend. The less the bend, the more energy that goes into forward speed and the less drag on the arrow.

When you think about it, logic seems to indicate that for a compound bow, using a release aid and a properly set up rest, the stiffer the arrow, the better. If this is not so, then I would love someone to explain to me why it isn't so.


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## lwilt

Corsair said:


> I do not really understand the issue of spine with *compound bows*.
> 
> I understand why one needs correctly spined arrows with a recurve or a long bow - the arrow has to bend around the riser and a finger release makes the string move sideways on release and therefore the correctly spined arrow will allow bending to compensate for these factors and enable the arrow to recover quickly after clearing the riser. Similarly, when shooting a compound bow using fingers for release.
> 
> But with a compound bow - *when using a release aid *- I do NOT understand why one needs the arrow to bend at all.
> 
> The arrow doesn't have to bend around the riser, because you are using a release aid, string travel is free of any sideways movement, the arrow rest is sprung, or drop away or non existant (as is the case of the air rest), so please explain to me exactly what benefit is gained by having the arrow bend in these circumstances.
> 
> When an arrow bends, it loses some of its energy to the bending process. This detracts somewhat from speed. In addition, bending increases the drag forces on an arrow. The stiffer the arrow, the less the bend. The less the bend, the more energy that goes into forward speed and the less drag on the arrow.
> 
> When you think about it, logic seems to indicate that for a compound bow, using a release aid and a properly set up rest, the stiffer the arrow, the better. If this is not so, then I would love someone to explain to me why it isn't so.


 OK, I'll try to explain for you. You've heard of Sir Isaac Newton I hope. His first law of motion: An object at rest or in motion will stay at rest or in motion unless acted upon by a force. In the case of the arrow you're applying a force to an object at rest and that arrow will tend to stay at rest until the string begins to push at the nock-end. Weight now becomes a factor as the point, usually being heaver, tends to stay at rest longer than the lighter weight nock-end and so, the arrow shaft is forced to bend to accommodate this condition. Can't escape the law of physics, Sir Isaac was right and all arrows bend when you shoot them.
This applies to all bows not just compounds. The arrow does'nt NEED to bend, it just does. Hope this helps.


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## Corsair

For IWilt

I will simply repeat what I said in my post in the hope that someone will read it, understand what I said and maybe answer it.



> When an arrow bends, it loses some of its energy to the bending process. This detracts somewhat from speed. In addition, bending increases the drag forces on an arrow. The stiffer the arrow, the less the bend. The less the bend, the more energy that goes into forward speed and the less drag on the arrow.
> 
> When you think about it, logic seems to indicate that for a compound bow, using a release aid and a properly set up rest, *the stiffer the arrow, the better.* If this is not so, then I would love someone to explain to me why it isn't so


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## lwilt

Now that you mention it I dont think anyone of the 350 people who have read this post gives any credence to a person who thinks that an arrow shot out of a recurve bow has to have the correct spine so the arrow can BEND AROUND THE RISER. Apparantly YOUR logic is flawed in some way or else your smarter than all the arrow companies out there. Otherwise with all their combined research and development capabilities they would have built only one arrow. The stiffest one, but since they didn't, they might answere your question. Or maybe Omar ibn al halif can answere you.


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## Corsair

IWilt

What a rude, supercilious person you are. Totally uncalled for and it is going to make you look very silly.



> I dont think anyone of the 350 people who have read this post gives any credence to a person who thinks that an arrow shot out of a recurve bow has to have the correct spine so the arrow can BEND AROUND THE RISER.


If that is the case there are 350 people as stupid as you and if doubt very much that this is so.

Being a nice guy, I'm going to help you.

Firstly, and this one is simple because it is clear that you are going to have some trouble accepting what is said:



> Simplified Arrow Dynamics: The "One Bend" Archer's Paradox
> The archer's paradox is most clearly observed with traditional longbows that do not have a cut away in the riser for the arrow rest.
> When shooting a traditional longbow, the arrow must point significantly to the left (for a right handed archer), yet a well shot arrow will shoot straight with respect to the centre shot line of the bow.
> The "archer's paradox" is that the arrow shoots straight, even though it starts off pointing outwards.






























> The crucial point is that *the arrow must be of the correct spine so that it dynamically bends around the bow*, the fletchings/vanes do not touch the riser or arrow rest and the arrow flies cleanly to the target.
> If an arrow of the wrong spine is shot, the fletchings, nock or arrow shaft will hit the bow. Indeed, consistently damaged fletchings/vanes are always an indication of poor arrow clearance.
> Thus, the archer, bow and arrows must be matched with each other.


Got that???

OK - now modern recurves and some so called long bows have centre shot cut outs in their risers to try to minimise Archer's Paradox but the arrow then bends around the pressure button (I presume you know what that is?)

Werner Beiter has a nice little video of this which should be clear even for someone as dense as yourself:

http://www.wernerbeiter.com/videos/Demo_3.mpg

Now, if you have been able to cope with this so far (and I do uinderstand what a reach it must be for you) there is this somewhat more detailed explanation of Archer's Paradox supplied by Dr. Robert P. Elmer:



> The Archer's Paradox
> The term "Archer's Paradox" was labeled in the mid 1930s by Dr. Robert P. Elmer, a well-known archery writer. It concerned the question as to why an arrow would hit a target when, from all appearances when placed on the bow, it should strike to the left.
> After a number of tests on shooting machines by several individuals and using the high-speed camera of Dr. Clarence Hickman, resultant slow-motion movies at 6600 frames per second produced the following sequence that shows the initial flight of a correctly-spined arrow from a well-designed bow. (A right-handed shooter is assumed)
> At full draw the arrow shaft is pointing at the target. The string, left side of the bow and the target are lined up.
> 
> When the drawn bowstring is released, a compressive force is applied thru the nock down the length of the arrow. In addition, for a three-finger release, there is a force away from the fingers, pushing the string and narrow nock to the left.
> 
> The string then snaps back to the right, pulling toward the center of the bow.
> 
> This action jerks the point to the left as it deflects off the bow. As the arrow passes about 1/3 of its way down the bow, it buckles even more, due to the pressure of the string and its flexibility, causing the arrow shaft to push the arrow rest slightly right.
> 
> Then the arrow bounces back away from the arrow rest a fraction of an inch and should never touch it again.
> 
> The inertia of the arrow point resists the leftward movement but the center of the arrow doesn't. Thus, the point moves around toward the front of the bow , causing the arrow to curve back around the arrow rest.
> 
> When the arrow leaves the string (which has been dragging the nock to the right (toward the bow), the nock reacts by snapping back to the left. The point, in reaction to the nock snap, moves back to the left again. As the feathers pass the bow, the point is back in line with the target.
> 
> As the nock end leaves the bow, it comes back in line, while the center of the arrow bends to the right.
> 
> The arrow straightens out and the center keeps bending to the left, but not as much as before.
> 
> The point and nock ends stay almost in line while the center of the arrow continues to vibrate back and forth, though less and less each time.
> An arrow must be spined correctly to oscillate at just the right frequency to *"bend around" the bow*. If it is too limber it will strike to the right of the target center. If it is too stiff it will strike to the left of the target center.


Now if you have been able to cope with that then a more academic and complete explanation of the process can be found at:

http://www.bio.vu.nl/thb/users/kooi/kooi98.pdf#search=%22archer's%20paradox%22


Frnakly I think this last one will be a bit too much for someone of your intellect but I put it up for the more intelligent readers.

As for you, I suggest you take no further part in this discussion as you already look silly enough.

Now - back to my original statement:



> When an arrow bends, it loses some of its energy to the bending process. This detracts somewhat from speed. In addition, bending increases the drag forces on an arrow. The stiffer the arrow, the less the bend. The less the bend, the more energy that goes into forward speed and the less drag on the arrow.
> 
> When you think about it, *logic seems to indicate that for a compound bow, using a release aid and a properly set up rest, the stiffer the arrow, the better.* If this is not so, then I would love someone to explain to me why it isn't so


Perhaps NOW there might be someone with sufficient insight to be able to answer my question?


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## lwilt

Read the part about the arrow companies and then look behind the button you are talking about.


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## Deezlin

lwilt said:


> How do you say that a properly spined arrow is good for shooting in open country. But not up close, 30 or less yards.


I don't think I said that, if I implied it, I didn't mean to. A properly spined shaft will work good at all distances. But, if you are primarily hunting close, you would be much better of a little over spined than underspined. In indoor archery competitions, many archers feel the stiffer the arrow is, the more accurate it is. This may be true for this specialized type of shooting, but I sure wouldn't want to try to kill an animal with those "logs" they use.

Hunters would in general, be much better off if they would buy an arrow to fit their mid range poundage adjustment and then work with the limb bolts or point weights to get a correctly spined arrow, than how fast they can make the arrow go.


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## lwilt

ok Deezlin, I like that.


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## Deezlin

Corsair said:


> I do not really understand the issue of spine with *compound bows*.
> 
> But with a compound bow - *when using a release aid *- I do NOT understand why one needs the arrow to bend at all.


Well, I really wish you would go out and invent one!!! I have shot all sorts of bows over my life time and I know exactly what you are talking about from the old stick bows and recurves, I use to shoot.

The bottom line is an arrow bends when it is launched from a bow. It really doesn't matter what type of bow it is. In order for the arrow to not bend it would have to be too heavy and large in diameter for it to fly any distance effectively. Then you would get into a lot of other aerodynamic problems and factors.

The more the arrow bends coming out of the bow the more oscillation which occurs and the long distance it covers before that oscillation ceases.

Now this oscillation is not all bad. Even a release shooter doesn't get a perfect, exactly the same, release every single time. He also need forgiveness in an arrow. This forgiveness is dictated by the spine. 

When the arrow is launched it starts oscillating about two points on each end of the arrow called nodes. These point remain on a the final arrow path. The weaker the shaft the more the bend and the more oscillation which will occur. If you make a bad release the arrow will bend more and it will take longer to recover than the previous arrow. But, if the arrows have sufficient time to stop oscillating before they hit the target then the one that bent more will average out it oscillation cycles about the same as the other arrow did.

The trouble with weak spined arrows is at close range they don't have enough distance to stop oscillating. So, if you take dead aim with each arrow, one is going to strike the target here and the other here and the dispersion of your close range grouping is larger than it should be.

The stiff arrow will work just fine for close range. The oscillation will stop and it will impact the target and have very tight groupings. But, it doesn't have forgiviness. If you make a bad release, if you are not aimed just right, or any form variation it will show this.

The other problem with a stiff arrow and is long distance groupings. The stiff arrow will stabilize too fast. So, again a bad release, or a little difference it the arrow itself, slightly changes it flight attitude when it stabilizes and by the time it hits the target, way out there, they are all over the place.

I hope this explains why, every shooter should have properly spined arrows. Oh, certainly there are the cases where indoors and FITA shooters many elect to go away from this, but in general, it is the case.


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## Donhudd

"IF" an arrow could be be constructed perfectly straight with perfectly uniform walls (both material and thickness) and supported with no contact except at the center of the nock AND "if" the force of the string could be applied directly inline with the center of the arrow, all of the force would be consumed in a linear compression around the center of the shaft and no linear bending would occur. 

Having said that , IF any one of the perfect conditions assumed above is changed, the shaft will bend. I prefer to have my shafts a little on the heavy side to minimize the bending effect.


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## Corsair

Deezlin

Many thanks for your thoughtful reply. At least you didn't behave as though I was a new arrival in kindergarten.

It ought to be clear from my lengthy posting in reply to IWilt's rude response to my first question, that I do understand the issue of why arrows bend in flight and the importance of selecting correctly spined arrows for a bow - *other than a compound bow.*

It's this latter that has exercised my mind constantly over many years and still does. Even your fine explanation does not clarify the issue for me any better than before, I'm sorry to say.:embara: 

Here's what I don't understand. Firstly, let's now forget about archer's paradox and the necessity for correctly spined arrows to shoot correctly with recurves and longbows. *I just wish to emphasise right from the outset that I am concerned only with the behaviour of arrows out of a compound bow, being shot over a properly set up arrow rest using a mechanical release aid.* I'm emphasising this so that other readers don't misunderstand my points. OK? 

Right - clearly one can never get an arrow that won't bend. Even an inch thick arrow would bend by a measurable amount, if you could shoot such a thing out of a bow. The bend may not be obvious but it would be there. So that is a given for all arrows.

The issue for me is simply this. I have shot many different types of arrows over the years I have been involved in FITA style archery and the one thing that has imprinted itself clearly on my mind in relation to the behaviour of arrows out of a compound bow has been that the weaker spined arrow never seems to perform as well as a very stiff arrow - and by this I mean a stiff arrow that is way over the recommended spines for the bow weight, cam type, release aid etc.

I've thought a lot about why this appears to be so and all I can conlcude is this. With a compound bow, the things that appear to eliminate the "bad" things associated with archer's paradox are the mechanical release aid and the properly set up rest. 

The release aid, in particular the really good quality caliper releases, allows the arrow string, with the nocked arrow, to travel forward with none of the sideways movement caused by using one's fingers for release, whatsoever.
The arrow still bends but as far as I have been able to ascertain that bending occurs mainly in the vertical plane in a porpoising action.

I have seen high speed videos of this which show some arrows with very little such bending at all. My theory is that the sprung arrow rest - regardless of type - acts like a shock absorber and tends to dampen out fairly quickly these vertical oscillations - not completely, because there isn't enough time for that - but to a certain extent. It has always seemed to me that on a compound bow, the thing to get right is the "springiness" of the arrow rest.

If it is totally rigid, then the arrow will behave, in the vertical plane, just like an arrows does, when it travels around a traditional long bow. As you make the rest springier, the arrow does not need to bend as much to overcome the resistance of the rest and some of its bending is absorbed by the rest. This can be taken to excess, I think to the point where the rest is providing no absorbtion of arrow oscillation at all and I'm not totally convinced (but I'm not sure) that this is a good thing.

Even the drop away rest provides a minor degree of absorbtion for a little while. The rest that really makes me ponder about this is the air rest, which by its very nature provides no cushioning whatsoever. Whether that is a good thing or not I can't say but I would love to see some high speed video of an arrow passing through such a rest.

Anyway, it is my belief that the sprung rest acts to provide a degree of absorbtion of the natural oscillations of the arrow caused by the thrust of the string onto its nock. Those oscillations are going to occur regardless of how stiff the arrow is, because that is how long cylindrical objects behave when given a hard and sudden kick in the a**e.

Now in a recurve or longbow, which do not have centreshot cutouts in them, it is not only desirable for the arrow to bend in the horizontal plane around the bow structure itself, it is essential that it does so, in a controlled manner so that the arrow won't go flying off to the left, but will, instead, bend around the bow and eventually straighten up along a path which will hopefully carry it on its way to the desired target. so the bending of the arrow with this type of bow is absolutely essential for good operation, particularly when a finger release is used.

But, in the case of the compound, there is no "need" for the arrow to bend so that it can get around an obstruction and continue on its way to the target. The bending that occurs will result from the natural action of a long cylindrical object being given a hard sudden shove at one end. How much it will bend will depend on the stiffness of the arrow itself.

Given that the mechanical release aid will, under most circumstances, release the string with the nocked arrow attached, without imparting any unwanted movement to the string and thereby transmitting that to the arrow AND given that the arrow rest, if it has been properly set up, will do nothing more than provide a degree of shock absorbing support for the moving, bending arrow, the question still remains - other than the normal bending that is going to take place in the arrow, why would anyone choose an arrow that has more bend in it than another that has less, to shoot out of a compound bow?

As I picture the whole process in my mind I cannot help but come to the conclusion that the more rigid arrow has to be a better performer out of a compound bow because the bending is dampened out far more quickly in a stiff arrow and the arrow is able to continue on its way with the minimum loss of energy and speed caused by the loss of energy through bending and the increased drag that this causes.


I don't see how a bendier arrow is going to be more "forgiving" of a poor release (in fact, using a release aid, I find it hard to envision how a poor release occurs). It seems to me to be more logical to choose the stiffer arrow for the reasons mentioned above and practise perfecting one's form so that induced errors are minimised.

So, I'm yet to be convinced that a compound bow should NOT use the stiffest arrow available as opposed to one which has a more "correct" spine (ie a bendier arrow) for that bow weight. I really do not understand this issue of "correct" spine in a compound bow at all, and even your thoughtful presentation doesn't help me in this regard, I'm sorry to say, Deezlin.:embara: 

I currently shoot the stiffest X10s that are made out of my compound and they perform beautifully. They are about two spines stiffer than the charts recommend but that doesn't seem to affect them adversely at all. Quite the contrary. So if I was ever asked for advice as to which spine to go for I would always say go for the stiffest made - only because it seems to be the logical thing to do.:confused3: 

If I'm wrong, I just wish someone would explain to me, in a way I can understand, why, keeping in mind all that I have written above.


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## Michigander

There are so many trains of thought on this post. I could type all day 
I think I'm going to stick to the general question however to save argument. 
I agree that a stiffer arrow will work well from a compound bow. The only question to me is how stiff you can go before you begin to loose accuracy.
Apparantly Gold Tip agrees also, many of the shafts they put out are a single, stiffer spine......the Series 22, X-cutters, and 30x's.
I think some bending is desireable however.(or paradox if you wish to call it that). You can get definent results from fine tuning a shaft that doesn't react wildly(this is also why a weak spine cannot be tuned). Have you ever noticed that even a change of launcher blades will help gain you points? This is because you have a well matched arrow that can react to small changes that are put in the arrow path. The same goes for adjustments on a plunger. I think the slightly stiffer shaft that doesn't react so much is more desirable..........at any distance. 
Now to the question of how stiff can you get away with? For the same reasons as above, too stiff of a shaft is not desireable. With little reaction from the stiff shaft during the shot process, you don't get the tuning ability that you have with the closer matched arrow.
Arrows don't just bend left and right.....they also bend up and down. I think this is what causes many people grief. Prongs that are set stiff will interfere with the path of the shaft. This is one reason a tuner blade helps gain people accuracy. The blade will move out of the way when needed, provided it is the right thickness. Slight adjustments help correct the paradox, and by the same token, help the rest stay out of the way when needed.
What I've found is that shafts that are chosen on the stiff side normally perform better for most compound archers. This is not to say that its better to go three frames ahead on the chart. There is in my opinion, too stiff of an arrow, just as there is too weak of an arrow to choose from.
Tunability is the key.
JMO,
Jerry


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## Corsair

Thanks for yout thoughts on the matter, Jerry.

Mine was and still is a serious query and an absolute puzzle for me. What I don't understand and still don't despite your input (and that of others) is WHY a certain degree of bendability is desirable in a compound bow. I accept what you say about arrow rests, having observed the phenomenon myself in tests I have carried out with my gear but what about the case of say, the Air Rest in which the arrow contacts nothing at all?

I am not trying to be argumentative here nor am I being deliberately dumb. It is simply that I do not understand the why of the matter or even if the thought that a certain degree of bendability is desirable is really true, or one of those things that seem to be true even if one doesn't know why.

I'm certain there must be a scientific explanation for one side of the argument or the other and would love to know what it is.

I thank you and others who have contributed well reasoned opinions on the matter but sadly for me, I am still none the wiser.:embara:


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## StevenB-NC

Corsair,

Now, I'll admit up front I'm no bowyer I'm just posting my opinion on the matter. In response to your question, I would think there would still be need for some bendability (spine, if you will) in the shaft to counter a few similar things that are needed to counter on a long bow....just not nearly to the same _degree_ as is required on a longbow. (not picking on the longbow, of course) And I think that measure of _degree_ is what might be really at issue. Agreed that with a finger shooter, the string will deflect as it rolls off the finger..but it will still do it with a release-just to a VERY much smaller degree. The jaws aren't going to be set perfectly square on the d-loop, and the loop will roll off one jaw of the release before the other- inducing a VERY slight vibration. The D-loop itself is probably not EXACTLY (and it has to be perfect, not close, but truly PERFECT) in the center line of the applied force, and so when the release does occour, the angle of force isn't going to be in a perfectly straight line- also inducing a slight 'wobble'. If the bowstring is pulled even a slight bit off-center during the draw, whether that off-center is induced from improper timing(again, however SLIGHT), or from not drawing the bowstring back EXACTLY perfect, even a slight degree of deflection will also induce a slight vibration. The manufacturing process might have close tolerances, But they are TOLERANCES...meaning that nothing is manufactured to the EXACT same PERFECT standards. So lets add tolerance allowances for the nock being SLIGHTLY off-center, shaft wall thickness tolerances, points not being truly round to tolernaces( all of these causing an offest, however slight, to the line of applied force), inserts not being consistent in circular weight distribution or even wall thickness, fletches not being equally applied nor weighing the same, nor perfectly centered around the line of applied force....we could go on and on listing things, just from a mechanical standpoint that induces slight, the key word here I think is slight, variances from arrow to arrow and shot to shot. Say nothing of the fact we haven't even begun to address the human standpoint introducing variances in the final equation. ALL of these variables, and more, build upon themselves from the moment potential energy is applied into the system until the arrow finishes its flight and releases the kinetic energy out of the system. The spine of the arrow simply allows for these miniscule variables and helps compensate for them. You simply aren't going to get SO many potentially different applied forces and variables to be exactly perfect in a repeated manner from current manufacturing processes. 

If you think about it, its really what makes a compound bow more 'accurate' than a longbow in the first place...all the individual variables involved that create an arrow shot are at SIGNIFICANTLY tighter tolerances. CAN a longbow be shot as well as a compound? sure it can, but you have a lot more adjusting of the variables involved to compensate for...and is what makes traditional shooting the more demanding and harder to master discipline. As we (as a people) have learned techniques to shooting better, use better materials, better manufacturing techniques with tighter tolerances and processes, the necessity for the arrow's spine to compensate for ALL, keyword is ALL the variables involved has significantly been reduced.....but we are still a-ways from eliminating it entirely. Hence, the need for SOME spine flexibility in the shaft of even the best set-up, manufactured and perfectly shot compound bow - we simply don't have the equipment (either manufactured or biological) of PERFECTLY re-creating the _theoretical_ perfect shot....nor can we do it repeatedly - however much closer we are to that goal than we were 4,000 years ago.


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## Corsair

StevenB-NC

That was a pretty sensible sounding explanation. If that is what it is all about then I have no trouoble accepting it because it seems logical and I would never have considered the problem from the viewpoint you presented.

Many thanks for that. I'm not altogether convinced that the arrow companies create differently spined arrows for these reasons alone but I don't want to go down that path.

I suppose the only degree of uncertainty that remains following your excellent reasoning is how much resilience is necessary in a compound bow arrow to compensate for the issues you raised.

I guess there is no way of working this out other than by trial and error. Bit of an expensive way to have to do it unfortunately, but I suppose if one is really serious about this game, it's something one might do.

Thanks again for an interesting and enlightening posting. I really appreciate it.


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## Michigander

I think we can now agree that some bendability is desirable no matter how you look at it. Weather its to help adjust flight, or so that it adds forgiveness to the inherit mistakes of equipment and shooter alike.
Now lets look at why the manufacturers choose to make different spine selections available to the consumer.........
There are a number of reasons the way I see it. First is the most obvious........
Archers are rich with tradition. Even sound science won't change most of our minds on a new way to do things in archery. For example.......If you were shooting when the compound first came out, how long did it take before you decided to finally try one of them "Newfangled Bows"? It took years for me! The fact is, there are still a lot of archers that think there is no place in the field for compound bows. Even the Olympics won't recognize them, even though it is a huge money sport all over the globe. 
The point is......archers would scream bloody murder if the arrow companies produced only one choice in spine selection for them to choose from.
As I said earlier, Gold Tip has taken that step with a few target selections only. I suspect they will never change their entire line over however.
Secondly...... The manufacturers know that we need those different selections. There are still a huge span of ages and sizes of people that enjoy archery. Matching arrows to their equipment is important. Show me an archer that never gets better, and I'll show you an archer that will give it up eventually. We try to teach equipment and technics to new shooters so they will hang with it.
And Finally..........MONEY!......There wouldn't be near the sales margin of shafts if a person could choose one shaft to fit all. I'd be shocked if a manufacturer tried to push this issue simply because it would cost them sales. How many of us have more than a dozen shafts lying around to use for different types of shooting? Most everyone I'd be willing to bet.:wink: 
There are more reasons than the short list of the ones I listed. These are just the first few. 
Pretty entertaining actually, if you think about it. I've enjoyed this thread and thought it would be a good idea to try to see it from the manufacturers side of things, since it was mentioned. 
JMO, 
Jerry


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## Deezlin

Corsair said:


> I am not trying to be argumentative here nor am I being deliberately dumb. It is simply that I do not understand the why of the matter or even if the thought that a certain degree of bendability is desirable is really true, or one of those things that seem to be true even if one doesn't know why.


The fact of the matter is compound archery want to achieve more accuracy. If they could they would want to one hole every single arrow. You are right in your reasoning, but the fact of the matter the arrows can not be made to not bend. Even if it could the compound archer still needs some amount of forgiviness for variations in the bow or arrow or himself.


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## StevenB-NC

Michigander said:


> .............. And Finally..........MONEY!......There wouldn't be near the sales margin of shafts if a person could choose one shaft to fit all. I'd be shocked if a manufacturer tried to push this issue simply because it would cost them sales.


Methinks you have it pegged, there, Jerry. Sales. I mean, afterall, the shaft has to be in the newest camo colors to match the bow, right?  Can't you hear the new ad campaigns? ..........

:horn: Its NEW! Its in the hot colors! Its got radial biased-ply forward S-5000 technology cross-rotated and flame-broiled for balance and strength! Nobody else has these! Its GOT to be better dangitall, than what you bought last week! You've just GOT to have a set else your scores will plummet, the deer will laugh at you and you'll l be less attractive to the opposite sex! My word, man, what are you WAITING for?!? BUY these new shafts!!

::cough:: yeah..or something like that, right? :wink: 

Steven


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## Corsair

Michigander, Deezlin & StevenB-NC

Many thanks again for your input. Everything you have said is logical and I feel a lot better about the issue now. I just have to determine now what the correct degree of bendability is for my set up so I'll progress incrementally on this with my X10s and see how it goes.


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## soldier

*Speed?*

I apologize if this has been brought up somewhere else in this thread, but I believe arrow speed is the answer to your original question. The stiffer the spine, the more an arrow weighs, at least in my experience. Unless someone wants more kinetic energy, a faster arrow is always more forgiving for inaccurate range estimations. It stands to reason that an average archer (myself included) would want the lightest possible arrow that will group well. 

Light = less spine = more speed = flatter trajectory. I'm not an archer who's hung up on having the fastest rig out there, but I like the idea of having the flattest trajectory possible.

I'm no Physics major either, but take it easy on me...it's my first post

-Soldier


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## BTM

Corsair: You and I must be brothers separated at birth, because I have loooong pondered the same things re. spine. Although I have an engineering degree, some of these matters are rather arcane and one needs to sift a LOT of chaff to get at grains of truth.

I primarily shoot 31" arrows with BHs, a d-loop, prong rest, and release, and have found that it's hard to go too stiff on the charts. One of these days I'll need to go to the Vegas shoot just to buy some time with that high speed camera and see how my arrows bend. (I assume most of the flex will be in the vertical direction.)

This has been an enlightening discussion; keep it up!


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## Corsair

Hi All

I just thought I'd post this answer I got from another shooter on a different Forum and I found it very enlightening.
This was posted by a chappie called Vittorio Frangilli from Italy whose son is Michele Frangilli, one of the top recurve and compound shooters in the world, so whatever Vittorio says carries quite a lot of weight and authority. The fact that what he says supports many of my own feelings doesn't hurt either.:wink: 

Here is what he says:



> Intersting topic... I remember some discussion already done about same subject but not were and when..
> Anyhow, my bit of basic available infos are:
> - Bob Ragsdale web site ... "there are no arrows stiff enough for a compound bow" (or a very similar sentence ..)
> - All top compound men using X10 are using 410 or 450 sizes heavily cutted on the back (up to 2 inches and even more) and they do not use 380 because "too heavy".
> 
> While it is not completely true that the arrow oscillates on the vertical plane, only (many high speed videos are showing also horizontal oscillation), surely compound is accepting a very wide range of spines. Basically, the maximum of the force is applied to a short segment of the arrow, so any kind of bending tends to happen on the second half of the arrow, while it is travelling out of the bow. This increases the tolerance of the acceptable spine, and also increses the need to have arrows stiffer at the end (cutted on back), opposite requirement from the recurve bow. The dynamic of the power stroke also changes the way an heavy point influences the grouping. It does, of course, but only in relationship to the flight of the arrow and the downrange part of it, not so much in terms of dynamic spine at the beginning of the flight.
> Same situation for the size of the vanes. Compound arrows need smaller vanes than recurve arrows to stabilize. Usually Compound archers use vanes bigger than they need, and recurve archers smaller than they should use.. (sentence by Don Rabska, not by me).
> 
> Summarizing, ideal arrow for compound should be as stiff as possible at least in its second half, have small vanes and then, as for recurve, have an heavy point and be as light as possible...
> Only problem, present arrows aren't stiff enough for modern compound bows, so proper arrows for 60 pounds and 30" does not exist, yet.



Some interesting points there. He also supports my belief that I have held for a long time that for a fast compound, one should use the smallest fletches available. I currently use Bohning X vanes (shield cut) and they are great. I'm actually thinking of cutting them down further to see how small I can go and still keep good stability. I have a feeling that with the correct point weight and arrow stiffness it should be possible to shoot really good scores with no fletches at all, out to 90m. One of our top shooters in Australia mentions one of his club members (might have been Clint Freeman) shot 345 out of 360 on the FITA target at 70m using bare shafts. Hell, if I could do that, I'd give up fletching altogether. I think there is a complete field of research here that could be explored profitably by those equipped to do so.


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