2018s=What Wood Shaft Spine?

[snag]

I just tuned some 2018s with 150gr. tips out of a Blacktail recurve, 55#@28". They left bullet holes in paper from 5yds and 15yds!
I was wondering what a 29" 2018 cross references to in POC shafts? Is there a chart to check this out?

[Eric in FLA]

A 29" 2018 is spined for 60#, check the link for a chart.
 http://www.arrowsbykelly.com/Spine_Charts.html

[Molson]

2018's spine around 66# @ 28".  Try a 65/70.  My Ramhunter longbow shoots 2018's cut 28" with 160 up front and 65/70's at 28 1/4 with 160 up front. Check the chart at Foxfire Archery from the Sponsor's list.

[SlowBowinMO]

I'll second that, a 65-70 should give you similar results.

[portugeejn]

Snag,
I had a question about the 2016's that I have.  They shoot like darts out of my Martin Savannah, but I like wood better and wanted to try them.  I was told the 2016 spines at 59# on a spine tester.  I tried 60-65 Douglas Fir and they seem to be close.  My guess is 2018's are probably 5 pounds heavier.  Someone here will know for sure, I am guessing.

RonP

[jacobsladder]

29" ...60#

28" ...65#

[laddy]

For a reason I don't quite understand, the wood spine and aluminum charts don't always work right for me. With 160 weight heads.  I find that 2018 can be to stiff when I get get 70 lb. woods to show me perfect flight.  On the flip side I get perfect flight out 1918s on 50lb. bows. with a variety of point weights and 2016 come out to stiff, they should be nearly the same.  I have concluded woods are more forgiving, but even that forgiveness changes if you compare extra heavy Rogue River to more average weight Rogue Rivers with the same spine. That is why i need so many bows, because no matter what they will fly right out of something.

[snag]

It is confusing to me too guys.  See the 2018s at 29" w/ 150gr. tips fly perfect! But out of the same centercut recurve I can shoot 80-84# down to 70-74# real nicely. I don't know if wood is just more forgive or what.  I will never forget the day I picked up this 55#@28" Blacktail recurve from Norm's shop. He took me outside after stringing it and handed me a couple of old ACME POC 80-84# spined arrows. I proceeded to drill his turkey target. When I asked him what spine they were I was in disbelief! He said that bow would handle a wide range of spines....But when I try to tune carbons (GT5575s) these shafts drive me nuts.

[snag]

Hi Ron!  What poundage bow is the Savannah?  Kathy said she saw you at the Christmas party. I was going to go over and crash it to meet you in person...but she couldn't find you again.

[portugeejn]

Snag,
My Savannah is 55@28, but I only draw 26 1/2 or there abouts, so I figure it is right around 50.  I should weigh it, as I have a scale-just never got around to it I guess.  

To bad I missed you at the Christmas Party-we probably won't meet now until the rabbit hunt in April?  Is Kathy's new job going well?  We all miss her.  

RonP

[dragonheart]

I have found th Aluminum and Wood arrows are more forgiving than most carbons.  I believe the carbons in general are too light in mass weight.  One thing to think about is this.  When you screw in a 150 grain head, it is really 175 grain total because of the insert.  2018 spine at 67#.  If you keep the point weigh the same as wood of comparable spine should shoot well.  With any arrow material for me 10-12 grains of mass weight per pound seems to give the most forgiving flight and quietness of bow.  The 80-84 POC shot good.  Maybe you just need heavier (mass weight) wood arrows.  I shoot 28" 2018's and weight them with poly rope inside behing the insert, 145 gr. BH, 610Gr. arrow, 63 @ 27" Bighorn Ramhunter Longbow.  You and carbon just do not get along.  I know the feeling!

Longbows & Short Shots,
Jeff

[snag]

I think you've got it Jeff...I'm just not a carbon guy.  I love wood and aluminum shoots consistant.

[John Nail]

If shafts are spined on 26" centers, why would you guys say a 29" spines less than a 28"? I understand that the longer shafts need to be stiffer, but 67 spine is 67 spine regardless of length. If you shoot 30" arrows like I do, you need to add at least 5 lbs per inch and add some more for other factors like centershot and kevlar string. IE: if my Bud shoots my bow at 55lbs and draws 27", he can shoot a 55 spine arrow. I draw 28.5 and shoot 30" arrow, and I need 65 spine. Two completely different arrows.

[Cupcake]

2016 spines 59.5# on the Spine-O-Meter

2018 spines 68#

I calculate that the 2016 should sine 59.3# and the 2018 67.9#.

I think that a wider range of woods fly well than aluminum because they damp the natural frequency faster.

Try this.  Clamp the end of a shaft in some manner with at least 24 inches protruding.  Pluck the end like a guitar string and observe how long the different materials take to stop vibrating.  There is something similar happening coming off the bow.
Kevin

[dragonheart]

You may be onto something with the vibration thing.  Carbons straighten out from paradox way faster than aluminum or wood.  Maybe this is where the difficulty in tuning themm comes from.  They react coming out of the bow with a dynamic spine (actual spine when shot) stiffer than other materials because they recover from vibration so much quicker.  Static spine is what the shaft measures on the tester.  

Jeff

[Rod Jenkins]

Shafts of the same static spine, will vary in dynamic spine according to weight...think about it this way....how much more resistant to movement away from the strings energy, will 600 grs vs 350 grs be? In other words...if 500 grs of arrow weight spines perfectly for a given setup, a 350 gr arrow will react, stiff, even if the static spine is the same...likewise a 600 gr arrow of the same static spine will react weak.

[wapiti]

BY golly Rod you've got it man!

[snag]

Rod, thanks for making it clear. If I wanted to add more weight up front what should I try? Go from 2018 to 2020? I am shooting 150gr tips now and am thinking of adding 50gr. to that.