Tip Weight/Spine

[DC]

In my quest for light arrows I'm playing with tip weight. If I reduce the tip weight by 25gr I can take 5# spine out of the arrow. Same dynamic spine and the arrow still flies nice and makes the arrow maybe 30gr lighter. Then I can do it again. Another 30gr etc. Obviously there is going to be a point where this goes bad. Is it when the FOC moves too far back?

[Pat B]

25gr lighter tip weight will increase spine value by 5#. Lighter tip make spine stiffer.
 Spined arrows shafts are sold as if they were a 28" finished arrow with a 125gr tip.  ie. shafts with an indicated 50 to 55# spine weight are to be used as a 50 to 55# spined, 28" arrow with 125gr point. Any changes to tip weight or arrow length will change the effective spine value.

[Danzn Bar]

 Seems like I've heard you say that before Pat....
 

[DC]

That's what I said. If I take 25gr off the tip it makes the arrow 5# stiffer so I can reduce the spine by 5#. Yes he has said it before and I think he misunderstood me then too.

[Pat B]

Yes, I guess I misread what you wrote.

[DC]

Sorry Pat sometimes I don't write very clearly.
So  "Obviously there is going to be a point where this goes bad. Is it when the FOC moves too far back?"

[Pat B]

I've not dealt much with FOC so I doubt I could give you a good answer. I guess if you are bare shaft testing the arrow would loose stability the farther back the FOC is. Fletching would change that though due to drag.

[TSA]

the turkish flight arrows actually have a negative FOC.
usually though negative foc is purported to cause arrows to somersault once the velocity bleeds off.

[DC]

There must be a saw off point with the FOC where accuracy starts to suffer and increasing the fletching size to compensate just bleeds off speed. I have to do some reading on your website.