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Main Boards => PowWow => Topic started by: snowplow on December 30, 2014, 04:19:00 PM

Title: Not the typical arrow spine question
Post by: snowplow on December 30, 2014, 04:19:00 PM
So unfortunately I have a set of arrows that are way too stiffly spined for me.

I was wondering how an arrow that is 'too stiff' would act on a bow cut to center or past center?

Or take that to the ultimate extreme for discussion purposes and how about for a compound with a drop away rest?

From what I know about spine and it's purpose, it seems like 'too stiff' would be impossible if you were shooting it out of a setup that didn't require the shaft to bend for clearance, such as on a traditional bow.

What are your thoughts on this?
Title: Re: Not the typical arrow spine question
Post by: McDave on December 30, 2014, 04:54:00 PM
It's true that bows cut past center have a greater tolerance for arrow spine variation than bows not cut to center.  Whether a bow with a drop-away rest would have an unlimited tolerance for high spine, I don't know.  Bear in mind that one of the reasons we select a particular spine is so the bow will shoot where we're looking.  I suspect that even if strike plate deflection weren't a factor with a drop-away rest, different spined arrows would impact the target in different places, so there would still be a particular spine that would work best with a particular bow and archer.
Title: Re: Not the typical arrow spine question
Post by: nineworlds9 on December 30, 2014, 04:56:00 PM
Center or more so past center will help a stiff arrow.  If you're using leather for a strike plate switch to a piece of soft-side Velcro it will help as it has more give.  You can also raise your brace height incrementally and it will help.  Additional point weight is always an option.  I tune full length shafts this way.  There's a point though where the arrow will just be too stiff if the general spine is just all wrong for the application, say off by over .100 or more and you have to front load the arrow beyond what gives you a pleasing trajectory.  This is an individual preference but I don't really like shooting more than about a 575-600g arrow on my 50# bows.
Title: Re: Not the typical arrow spine question
Post by: BAK on December 30, 2014, 06:09:00 PM
A perfectly tuned compound bow with drop away rest and mechanical release should theoretically shoot any spine arrow.  That is not true if your shooting with fingers as the string rolls off the fingers and imparts flex to the shaft.
Title: Re: Not the typical arrow spine question
Post by: damascusdave on December 30, 2014, 06:14:00 PM
There are a pair of Docs on here who know all about this but I will be darned if I can remember their names

DDave
Title: Re: Not the typical arrow spine question
Post by: Hud on December 31, 2014, 01:25:00 PM
The following is for traditional bows, only.

There is a difference in the paradox for a given bow, depending on design, speed of the bow, the amount cut past center, point weight, string weight etc. Shooting a longbow with the least amount of center shot would normally take a weaker spine than a faster bow.

I would suggest reading the article by Denny Sturgis Jr. in Traditional Bowhunter, Feb/Mar, pages 78-79. It is about paper tuning, but if you read further, he tells the reader how to adjust for a weak, or stiff spine.

Also read:    http://elitearrows.com/proper-arrow/  

Keep in mind that wood arrows are spined at 26" centers and Aluminum and Graphite on 28". Wood arrows generally have a specific spine and tolerance for correction and graphite the greatest. That means, a 50# longbow may only shoot arrows spined for 55-60#, 50-55#, or 45-50 depending the draw wt, draw length and length of shaft. You will find a spine chart, and conversion for the three different shafts, at:

 http://oakcreekarchery.com/ocapages/spine/docs/arrow_translation.pdf
Title: Re: Not the typical arrow spine question
Post by: JamesV on December 31, 2014, 01:48:00 PM
I shot compound for years and never worried about the spine of the arrows. They all shot good but I did not shoot ultra light arrows with broad heads like I did for 3d using nib points.

James
Title: Re: Not the typical arrow spine question
Post by: **DONOTDELETE** on December 31, 2014, 02:25:00 PM
QuoteOriginally posted by BAK:
A perfectly tuned compound bow with drop away rest and mechanical release should theoretically shoot any spine arrow.  That is not true if your shooting with fingers as the string rolls off the fingers and imparts flex to the shaft.
Actually.... This statement is not completely accurate... You do need to take into consideration how much draw weight And how aggressive the cams are. For example a lighter weight target bow with round wheels will take a much softer spine than something 70# with hatchet style cams.

If you shoot to soft of spine out of a compound you'll have issues....

On a traditional bow tuning carbon shafts i've always leaned a bit towards the weak side on spine, and shim my strike plate out to fine tune.
This slightly weaker spine is more forgiving if you don't quite reach your anchor point than the arrows that are stiffer. The stiffer shafts seem to be more sensitive to a less than perfect release too.

Of course your mileage is going to vary depending on the bow you are shooting and the grains per pound ratio. Heavier arrows are going to be more forgiving than ultra light shafts.
Title: Re: Not the typical arrow spine question
Post by: snowplow on December 31, 2014, 03:32:00 PM
Thanks guys. That all makes sense to me. Happy new year!