Arrow. Weak/stiff. My take

[enewman]

Arrows weak/stiff
Let's look at arrows.

Spine of an arrow is set by a manufacturer. It's tested with arrow setting at two points. 28 inches apart. Center of arrow is 14 in. Then we test with a 1.94 lb weight.

Now when you cut a arrow shorter then 28 inches. Are we making the spine stiffer. NO. Static spine does not change.

you would need more weight. To test. You could take a arrow and set it at 20 inches. With the center being 10 inches. If you had the correct weight. Say 3 lbs. It would show the same static spine. Same going the other way. You could test a 30 in arrow, but it may require say a 1.4 lb weight. This was just a made up number.

Remember years ago amo method was at 26 inches with a 2 lb weight.

So why do we say if we add more tip weight it makes the arrow weaker. Does it. NO. Not static.

So does adding more weight do.

First you need to under stand an arrow has nodes. A node and B node. A is up front B is in the back. So as you add tip weight the A node will move closer to the tip. This increases the width where the shaft is going to flex. Thus giving you a weaker dynamic reaction. This is caused by the amount of weight so at the shot the arrow compresses do to the tip weight. Same as you add more weight to the back of arrow. Even though the B node now is moving back and yes the flex area is getting bigger the tip weight is not getting heavier. So at the shot the arrow does not compress as much. This giving you a dynamic reaction that shows to be stiffer.

why do some arrows say 300 spine shoot better then others. This has to do with how it's made. You can take two arrows with same static spine. Both check good, but one arrow is not made with same process. So the dynamic reaction will not be the same. This is why the programs while a great tool, has its flaw. This is also part of the reason they tend to lean on the stiff side when calculating

Now can an arrow be weak or stiff. NO. but it can be underspined for that bow and or that amount of tip weight. Can a arrow be overspined. No. But there can be a arrow that may shoot better for you. How do we test this. We need a dynamic tester. Good thing is we all have one. It's your bow.

[Limbwalker]

I use a ball and stick analogy. (you know, the "KISS" principle. )

If you have a ball and want to push it with a stick, you apply force with your hand to the back end of the stick. If the ball is heavy and the stick is thin, it will bend before the ball starts to move.

So in this analogy, the ball is the point weight, the stick is the arrow, and the hand is the bowstring.

What we're after is the right amount of flex or bend in that stick. Too much or too little will make the arrow shoot right or left.

How do we change that? If we want more bend we have four options:
1) heavier ball,
2) a longer stick,
3) a thinner stick, or
4) more force.

If we want less bend, we have the same four options but in the opposite direction:
1) a lighter ball,
2) a shorter stick,
3) a fatter stick, or
4) less force.

To me, that's easier for people to visualize. I rarely mention "nodes" unless I have to, because as soon as I do, people's eyes usually glaze over.

[enewman]

But maybe we need to be talking about nodes. That way the eyes don't glaze over.

[Fergeris]

Tagged for reading later

[Limbwalker]

But maybe we need to be talking about nodes. That way the eyes don't glaze over.

You can if you want, but I find discussing the nodes to be the most confusing way to explain paradox and spine selection.

[popup_menace]

I love all these arrow threads. I went from a speed freak to a weight/foc junkie just from reading threads like this and many others

[enewman]

I love all these arrow threads. I went from a speed freak to a weight/foc junkie just from reading threads like this and many others

It's not my fault haha

[TEXAS 10PT]

I love all these arrow threads. I went from a speed freak to a weight/foc junkie just from reading threads like this and many others

Then why are you only shooting a 415gr arrow? That is a toothpick to me.

[popup_menace]

Then why are you only shooting a 415gr arrow? That is a toothpick to me.

Because us poor folk make due...


In all seriousness, I will probably toy around with a 475-500 grain setup during the "off season". I am looking to stick a big axis or aoudad in April, so maybe by then I will have some black eagles

[FULL DRAW]

Question since y'all see to know what y'all are talking about. I have a Hoyt Charger now and it shows to be about 325 fps at 70lbs. I will probably set it about 63-65 pounds. It is a Cam and a half system. I am tall so I shoot a 29.5 draw length. I am about to get some arrows cut in the next week but have been scratching my head around which arrow will be best for me. I would like to shoot a 100 gr broad head fixed or mechanical. I want to try both. I had heard from someone that if I shoot a longer arrow it might be a good idea to shoot a heavier arrow set up so that I get less flex and will fly a little truer. Thoughts? I have noticed in the past with some cheaper Cabelas arrows, $69 a dozen, I could see the arrow flex in air. I switched to some Eastons and had better results. I just want to get a good starting point for which arrow might be best for my set up.

[TEXAS 10PT]

Because us poor folk make due...


In all seriousness, I will probably toy around with a 475-500 grain setup during the "off season". I am looking to stick a big axis or aoudad in April, so maybe by then I will have some black eagles

I shot an Aoudad with a 600gr arrow. 185gr broadhead with 1 7/8'' cut fixed head. Got a complete passthrough broke ribs going in and out and he still went 700 yards. Tough animal....go heavy as you can.

[Fergeris]

I had thought that my .300 were weak but the more I have shot this new bow learning from Newman an Hoyt21 grip is alot of my problem. It's amazing what grip does. But now just with a slight change in my grip I can get the arrow to show weak or stiff

[Doc Peter]

To me, that's easier for people to visualize. I rarely mention "nodes" unless I have to, because as soon as I do, people's eyes usually glaze over.

But don't the nodes really come into play when we look at the effect the string has on the arrow, particularly as the arrow bends left and right as it is being launched. From what I have gathered that is the whole reason people paper tune. If the spine isn't correct for the upfront weight the arrow has to flex more to overcome the static inertia of the tip. The flexing back and forth doesn't stop instantly as he arrow moves forward, it continues for several feet wobbling back and forth. And these "nodes" are not necessarily at equal/same distances for different bows and arrows.

Or am I totally wrong?

[Doc Peter]

I had heard from someone that if I shoot a longer arrow it might be a good idea to shoot a heavier arrow set up so that I get less flex and will fly a little truer. Thoughts?

Interesting question. I have been shooting CX Pile Driver Hunter 350 cut to 27" with a 28" dl and 65# dw 125 gn tip from both a Hoyt NT and PSE Prophecy. Avg arrow weight is 479 gn. This arrow seems to fly and group better for me from either bow than say a Gold Tip XT 340 or even Easton Bloodline.

So now my question is are heavier arrows better to shoot than light ones? Mine appear to be.

[JakeGraves]

The reason this testing method cannot be 100% is because it tests perpendicular to any stress exerted on a shaft.
Testing also does not factor the fact that larger OD shafts are inherently stiffer than same material and weight in a smaller diameter. A better test could be a compressive load concentric to centerline with a dial indicator measuring flex at a given load. This could also prove what side of arrow is stronger.