ugg, newer longbow designs and spine

[AkDan]

Boy, been playing with a bunch of different bows lately and i've noticed most of them needing stiffer and stiffer spines, ugg.   Think I figured out tonight I'm over drawing just a tad, but still, needing an 80-85 85-90lb spined cedar out of a r/d longbow (60lbs) seems awfully high!  

Dunno what made me do it, but bent my elbow just a hair and presto, peferct bareshaft flight.  Took a look in the mirror and it seemes to me that I'm over drawing, double ugg.  

Boy and now my wifes going to find 2 holes through the back of the door, my bare shaft test range is the living room to the hall way, ya might be a redneck if...............UGG!  

What a nite.  

Now I built the site window out, thought about going to a smaller diameter string (using a 15 strand dynaflight string right now), other then going to a b50 string what else can ya do to get a bow to shoot a lesser spined arrow.  These are just test shafts so they aint capped and crested, figure that'll bump up dynamic spine a bit.

Atleast this go around, the ups and downs are out, and I've figured out the lefts and rights.   To much fun, but boy it can be flustering some times.

[Danny Rowan]

If they are flying great for you, why do you want less spine?

Sounds right to me I shoot 60 pounds both curve and r/d longbows and that is the spine I use. I want the weight. All of my hunting arrows are 800 gr plus and my target arrows are at least 650gr. for carbons and 800 for wood. Just my two cents.

Danny

[wingnut]

Dan,

Spine is just a number not a rep to poundage.  The new bows produce the speed and KE of bows 15 - 20 pounds heavierthen bows built in the past.  Heck even our bamboo and wood bows are shooting spines heavier then the weight of the bow.

MIke

[AkDan]

I know I know, just complaining   .  Heck finding wood that stiff is tough at best!

Thought about giving allegany a call and going back to some ash just to slow it down some.


Got to admit, it sure is nice knowing what it wants, but dog gone it, why so stiff ugg.  Might have to get me a wesley special just so I can shoot woods instead of needing rebar  

[aromakr]

Dan:
All your problem is due to center shot or past center bows, It has absolutly nothing to due with a bow shooting harder!!!! When the strike plate moves to center or past center spine must increase to reduce the paradox, if you don't the arrow will shoot weak. Also you did not mention the arrow length, every inch past 28" will weaken the spine 5#. And if you are over drawing your bow weight is heavier.
Bob

[Carbon Caster]

Bob,

You have been building wood arrows since I was in diapers, but I beg to differ with you on the shooting harder bit.  Just last night, I shot an arrow that was tuned to a R/D longbow of mine out of an Adcock ACS CX of the same weight and with a shelf cut to the same distance as my bow.  The arrow almost went sideways back and forth down range from being WAY to weak.  Bow efficiency has proven to me to be a definite part of the spine choosing equation.  It is not the Only part, but absolutely a part; as is string material, how far to center or past center the shelf is cut, actual draw weight, and arrow length and point weight.

These are just my observations but definitely not just conjecture.

[Orion]

I've always found on centershot bows that I could shoot way over the bow's draw weight in spine.  Didn't have to, but could.  For example, out of my 52# Shawnee, which is cut a little past center such that my arrow bisects the string almost perfectly, I can shoot 55# to at least 75# cedars.  Could probably shoot heavier shafts as well.  Just haven't tried.  For me, centershot bows and bows cut past center have always handled a wide range of spines, but I usually haven't found it necessary to overspine by much.  Bow design and modern materials might have more to do with requiring a heavier spine.

[aromakr]

Carbon Castor, Orion:
To put as simple as I can, correct spine is nothing more than finding an arrow that will print on a verticle line with your point of aim.
I will be speaking of a right handed shooter.

A bow that is less than center, the arrow needs to bend around the riser and then come back in line with that point of aim at impact. If the arrow is too stiff it will not bend enough and will impact to the left of your aim. Conversely too light a spine will cause the opposite.

A center shot bow, the arrow will not need to bend as much to hit the point of aim, so it needs to be stiffened slightly.

A past center shot bow will need to be stiffened even more. There are trade offs with each type. The reason many bowyers are going to the past center shelf is because it allows you to use a wider range a spines. Once you reach the minimum spine need for that bow you can increase the spine as much as 40-50# and they will still shoot well.

I have one client shooting 120# spine shafts out of a 74# bow, they fly like darts.

My post to AkDan, was in reference to his problem with cedar shafts, Carbons are in a class by them selfs.
Carbon Caster: I agree with a lot of what you said, however I have never found that string material made enough difference to worry about, and a factor that many forget to consider with carbon shafting is its diameter. A bow cut 3/16" past center, the small diameter shafts will actually be further past center than they should.
The absolute center of the shaft should never be to the right of the center of the limb.
When the leather strike plate is in place an 11/32" shaft's center should be in line with the limb center on a 3/16" past center shelf. If the shaft diameter is smaller then the strike plate should be moved to the left.
Bob

[AkDan]

Bob,

Yuppers, I'm aware of all that (window cut to center or short of center, bow design, drawing past 28 which I know I do normally but it looks like form wise I'm drawing too far, and to a lesser extent string material).  

I wonder how much string diameter, ulitmately string weight plays into this.   gonna try going from a 15 strand dyna 97 down to a 12 strand just for kicks and see what happens.  The strings going to travel faster, however it shouldnt follow the arrow as far which should increase dynamic spine I would hope.    

This bow is 58@27lbs 66"es, I'm drawing a 28.75 bop poc ONTO the shelf, make no mistake there is no short draw, I tend to hold almost as long as some compounders!

I've bareshafted everything up to an 81lb spined cedar.  

Built out the site window some, might go a lil more to see what happens.  I did get my arm directly inline with my shaft as opposed to slightly behind my head and dropped my bow elbow just a skosh, which put me closer to a regular 28" draw and presto, 75-80's is what she liked, in particular a 78lb spined bare shaft with the built out site window.  

Its fun in one hand, but frustrating in the other!  MIght be a good time to go back to barreld ash shafts.   Have been contemplating it for awhile now.  Think I'm going to order up a test batch in spines as I've done with POC and see if what I've believed in years past holds true.   This bow is the perfect ginney pig.

[Jay Campbell, JD]

Dan, I was finding cedars at 100-120# to shoot out of my wife Karen's Adcock bows.  Not many of those around. However, if you get them made out of IPE or Purpleheart, they will have the spine, but be real heavy too.  For our buffalo arrows, we're shooting Gold Tip Big Game 100s (well over 100# spine), with an easton 2316 glued inside full length to get enough spine and handle the weight up to 900 gr.  That's for her 67# Adcock ACS, and my 80# Black Widow PLX. - Jay Campbell, JD

[Gordon martiniuk]

Carbon caster is right I watched him shoot a arrow sidways out of Petes Bow and Pete will tell you you have to tune your arrow to the bow I did not Beleve him but have rethought my opinion as I own many spline and weight of arrows and not all shoot good from one bow every bow will have its favorite that will make your bow more forgiving and thats wher its at          

[Carbon Caster]

Don't give out the secret as to how I knocked it to shoot it sideways.  LOL!!!

Good to see you here.

[aromakr]

AkDan:
I just re-read your origional post, did not realize you were bareshaft testing, that will increase your spine need. Try some 75/79's cut 28.75 BOP with feathers! I would bet they will fly like darts.

[jacobsladder]

Just some points to keep in mind.  I believe I read this off of Doug Besherse site.  Points to remember on spine.  Fast flight string pounds the arrow with basically no give. Add 10-15# in spine for wood arrows.  Bow quivers have the affect of stiffening the spine.  Large feathers stiffen the spine.  An then the obvious... draw weight, arrow length, off set in riser, point weight. He also states that most hunters are border line too stiff.  When picking your spine you should consider that most hunting shots are not in ideal situations.  Cold mornings, extra clothes, and awkward positions.... this all makes sense to me and I thought I would share.  
take care...

[AkDan]

Bob,

Have been playing with that spine group.   Didnt get to the range today and got tired of poking holes in the back side of our front door (thankfully it's a cheap one LOL).  

Had to change the nocks out.  The 11/32nds bohning classics are a much tighter nock then the 5/16ths bohning classics.   Using a 15 strand dyna and forgot the size serving (largest spectra).  Fits the 5/16ths extremely well, overly tight on the 11/32nds   I'll let yall know tomorrow how they fly.

[Orion]

Arrowmaker:  I think we're saying the same thing.  My example re being able to shoot 55#-75# and probably heavier shafts out of a 52# past centershot bow jibes with your statement that "once you reach the minimum spine (on past centershot bows) you can increase the spine by as much as 40-50# and they will still shoot well."

[Bjorn]

My bows are not nearly as heavy as some that have been mentioned; but still my 52# Morrison and 50# Fedora are both using Dynaflight strings and need 75-80# cedars to be happy.

[AkDan]

guess I was lucky with my old crusader.  It shot 65-70's really really well.  

The bow as 60@28, I'm pulling 28 3/4" arrow all the way back, dyna string 125 head.  

To bad it cracked!!!

[AkDan]

well tonight things look a little better.


Still not getting consistent enough results to really show anything though the 75-80's seem close, then again I aint getting much for groups either.

I did paper tune them and I kept getting a 1/2" nock high kick no matter what I did, no left or right though so I bet they are on.  

Now what in sam heck, 2 different bows in a row now from 2 different bowyers I've ended up with a really low nock point and a consistent nock high kick????  I did find an arrow that pretty consistently showed heavy.  was an 81lb bareshaft.

Well after some more playing in the house tonight I think I might have put the whoppn on the nock high, atleast at shorter ranges.   Not sure  but it appears this bow is even tillered (I bought it used and didnt think to even ask 3 or split).   So I built it up.  Also put a lil more pressure on my top finger and viola, looks like the up and down is fixed, atleast at 10 feet LOL!

The new bow is going to be done in a week, woohooo!!!  I get to start all over again haha.