400 carbon = what in wood?

[F. Dobbs]

Anyone?

[stonekiller]

My ace spine tester says 65lbs.

[F. Dobbs]

Wow, i was guessing 50/56s max.

[Orion]

Actually .400 spine in a carbon is equivalent to about 78#-79# in wood. 

Stonekiller.  You're probably measuring on a spine tester set up for measuring wood arrows with a 2# weight and the posts 26 inches apart.  The method used by Easton, and all other carbon makers, uses a 1.94# weight and the posts 28 inches apart.

A .4 deflection on the former is 65#, but .4 using the Easton method is 78#-79#.  So, OP, if you're shooting .400 carbons and you want wood spine to match, it will be 78-79#.
 

[F. Dobbs]

So, if I'm shooting 400 spine carbons out of a 50# bow I need a 75- 80 spine in wood????

[Orion]

Strange as it may seem, yes.  That being said, I expect the .400 carbons aren't well tuned to your bow. Very likely more spine than you need, but lots of things affect tune.  A low stretch string, long draw length, more bow center shot, point weight, etc. require more spine.  Your shooting form also comes into play. 

If you don't have a long draw length, and your bow isn't cut at least to center, and you're not shooting a low stretch string and relatively heavy points, I suspect you would need quite a bit less spine.

I'll add my own example.  My elk arrows are .400 spine carbons that I shoot out of a 50# cut to center Bear TD at my 28-inch draw length. However, I have the shafts front loaded with 350 grains for a 650 grain arrow.  Without that much weight up front, they would be too stiff.

I can also shoot .500 spine carbons with 200 grains up front out of the same bow, with excellent arrow flight. 

[Terry Green]

Orion, I have acquired a 55 and 50# bow for layer in life.  Been shooting heavy bow since a kid and still am.... however, well just check this thread out... recommended spine from D n M and Big Jim..... also shooting 400 darts from the new trad only barebow shafts...... 29 bop and i draw just short of 28.

http://www.tradgang.com/tgsmf/index.php?topic=167279.msg2862776#msg2862776

[Terry Green]

And a 175 grain head.

[Orion]

I don't doubt they work.  I think the combination that ended up working best for you in the flagged post was a .400 grain arrow with 225 grains up front out of a 55# bow.  There's just so many things that combine to determine the particular spine that works best for us individually.  I probably should have asked what kind of bow, arrow, point weight, etc. the OP was shooting before I suggested he likely had more spine than needed.  For some bows, yes, for others, no. 

Too, it's also been my experience that I get good arrow flight by overspining.  Thus, while .400s at 78-79# spine would seem too heavy for a 50# bow on paper, they obviously work in some situations.

[Terry Green]

I'm shooting 400 barebows, centershots and dark timbers from both 55 and 50# bows.  Those 3 are all lazer beams. The 330s not so much.  I didn’t think they would be that high of a spine in woods.  Heck if I know. 

[Kelly]

Actually .400 spine in a carbon is equivalent to about 78#-79# in wood. 

Stonekiller.  You're probably measuring on a spine tester set up for measuring wood arrows with a 2# weight and the posts 26 inches apart.  The method used by Easton, and all other carbon makers, uses a 1.94# weight and the posts 28 inches apart.

A .4 deflection on the former is 65#, but .4 using the Easton method is 78#-79#.  So, OP, if you're shooting .400 carbons and you want wood spine to match, it will be 78-79#.

Jerry, you’ve actually got this backwards. A 400 spine carbon will be quite a bit stiffer at 26” centers than at 28”. According to Easton a .400 spine on 28” centers is 70#. 28 divided by .400 = 70#. Now if my memory serves me correctly a .400 spine done on a 26” center spine testor like my Scheib(same one Easton uses) except mine has a 2# weight it will measure close to 80# or .325.

[pdk25]

OK, so does anyone know what the wood # equivalent of a 500 spine carbon is?  Thanks in advance.

[Magilla]

I may be looking at this all wrong but if a 400 flys good then check that shaft on a spine tester  at 26” with a 2oz. Weight and it is 72# and a 500 is 62# on my Ace spine tester. That should give you the comparable wood shaft.

[Orion]

First Madre:  I forgot one other factor in arriving at your arrow spine, and that is arrow diameter.  I expect your carbons are 5/16 or smaller in diameter, while your woodies will be 11/32 or larger.  That means that the center of the arrow will be further from the center of the bow, which in turn means that it will need to flex more/be a little weaker to clear the bow.  Thus, 70-75# spine in wood will likely work better for you than 75-80# spine.

pdk:  a .500 spine in carbon is equivalent to a 62-63# spine in wood, as Magilla points out.  If you make the conversion, don't forget to consider the effect of arrow diameter. 

Kelly:  Don't think I have it backward.  Yes, if a carbon is measured on 26-inch posts, it would be quite a bit stiffer. I'm working from a Deflection and arrow spine weight chart I found on wwwRangersArchery.com a while back. It lists .40 deflection using the 1.94# weight and 28 posts as 78-79#.  On the same line, it lists that weight (78-79#) as as yielding a deflection of .33 on a tester using a 2# weight and 26-inch posts.  Which is exactly what you said, and the recommendation I offered to Madre.  That is a .400 spine carbon (measured one way) is equal to 78-79# woodie (measured the other way). 

What doesn't fit is (According to Easton, a .400 spine on 28-inch centers is 70#.) If that's the case, this entire chart is wrong. But I don't think it is.  I've also seen conversion ratios (that I can't find right now) that yield the same results as this chart. 

[M60gunner]

Without the bow weight at his draw we are spinning the wheels. His 400 spine arrows could be overspined for his bow? Besides, it harder to add weight to a wood shaft to compensate for overspined shafts than carbon shafts. Not everyone wants to buy special weights or jigs to drill the shaft to add weight. Why not just use the old 5# rule from his draw weight? Buy a test kit of shafts, get the intended point weight and go from there?

[F. Dobbs]

Actually it doesn't matter.  I'm shooting 400s with great flight, and have been for years.  I just would like to get a nice set of wood arrows that will spine the same.

Now I'm totally confused by all these different answers

[Kelly]

A 500 spine carbon done on 26" centers with a two pound weight is 65-70#(depends upon brands).
A 400 spine carbon done on 26" centers with a two pound weight is 75-80#(depends upon brands).

Really carbons are nowhere as consistent in spine nor weight(unless you pay tons of $$$$ for matched) as aluminums. I said earlier from my memory when I last spined these shafts on my Scheib Spine Tester back in 2005 when I was still in the business. This was after I corrected the faulty scale that all spine testers have over 65#. Never used or seen an Ace so can't say if their scale is correct or not, but I know Scheibs and Adams are off. Base everything off of .260 is 100# spine and .520 is 50# spine. To figure your own 26 is divided by pounds + deflection OR 26 divided by deflection + pounds. This is the AMO method for wood shafts and everything else I've tested over the years to compare spines. If you'll look on my old website it will tell you the spine of various shafting.

[Tim Finley]

I shoot a 400 carbon from a 50# bow and get perfect arrow flight and from a wood shaft I spine mine at 58 to 62# the heads on carbon are little heavier 145 grain and on wood 125 grain . With a 28" draw . I might add I have spine tested several 400 shafts of different makes and they were all different spines . Try wood in  a 55 to 60 lb. or 60 to 65 lb. spine.

[Orion]

Madre.  We've given you the carbon conversion to wood, but as I noted in my first post, a whole bunch of things affect the spine you'll need because wood has other properties that carbon doesn't.  As I also noted above, it's generally larger diameter. It's generally a bit heavier per inch.  Often can't load the front end as much as one can with carbon.  It doesn't recover as fast as carbon. 

Regardless, we're all pretty much guessing regarding what might work for you. If you tell us the kind of bow you're shooting, how the arrow shelf is cut, type of string, the arrow length and point weight you want to shoot and the draw weight at your draw length, we can give you very specific recommendations.  For example, Tim just provided one combination that works, but if your draw length, bow type, point weight, string type, etc., is different, you'll likely need a different spine. 

Or, you could use the spine calculator on the 3-Rivers site to get you in the ballpark of what you will need.  It asks for the same type of information.  Or, ask the shaft vendor what you will need.  He/she will also ask for this information in making a determination. 

[rainman]

Call Paul Jalon at Elite arrows and talk to him.  I have had 2 sets of arrows from him and they hit exactly where I aim.