OK....so I've been shooting 3D with my 50# set of limbs (60" bow). I'm shooting a CX Heritaage 250 @ 30" w/ a 175gr. FP.
I switched over to the 56# limbs, today, to bare shaft tune (62" bow). I wanted to find out what I needed to build my hunting arrow. My findings were interesting.
My hunting arrow will be nearly identical to my 3D arrow....but 1" longer. Hows that possible? I do have a quiver mounted at my limb bolts, but that's the only difference. Same riser.
I chrono'd the 50# limbs @ 171fps. I chrono'd the 56# limbs @ 181fps, today.
What could make the heavier limbs need a weaker spined arrow? Overall bow length? Quiver (loaded with 3 arrows)?
You probably just have more spine than you need with the lighter set of limbs. Most bows will shoot overspined arrows quite well. Your heavier bow will no doubt shoot even heavier spines well also.
Orion....I don't doubt you, but I've bare-shafted extensively with the 50# limbs. I can't shoot 150's.....and I can't shoot 250's (same length) with lighter FP's (stiffer spine). It shoots what it likes....and I don't try to influence it too much.
I can't shoot even the SAME arrow out of the 56# limbs that I shoot out of the 50#'ers. I can't explain it. It's either a freak of nature; the overall bow length or the quiver loaded w/arrows.
Take the quiver off and see what happens. I doubt that is it though.
I just did the exact same thing recently except for the changing of bow length and found the same thing. I chalked it up to once you get the carbons tuned in, they are pretty forgiving and I was on the stiff side of tuned with weak limbs and the weak side of tuned with the heavy limbs...
Have you scaled the 56# limbs? Are they made of the same materials? Other variables come into play.
They're not the same veneers.....but it's a 3 yr old Shafer Silvertip. I haven't put the limbs on a draw weight scale and likely won't (what's the point?). The gentleman I bought the bow from said the bow had never been strung with the 56# limbs. It had 2 new strings for that set of limbs....and I got the 1st one out of the package.
This bow's a LOT more finnicky than the RER was. Ive gone on both sides of where I am, now, with both sets of limbs. It likes what it likes. I can't explain it, though.
The quiver effects things.That is why you tune with a quiver and arrows on the bow if you are going to use it that way.The different balence makes the bow move different on release.Most times you use a bow quiver you will need a weaker spine than if not useing one on the same bow. jmo
James....
I was at Page's house tuning the bow I'll be hunting with, this morning. It was perplexing to both of us. I've had Page present each time I've tuned arrows, so far. If there's someone more in the know, I don't know him.
I just thought I'd see if anyone else had experienced this.
GMMAT you got a 10 FPS gain, which is about right for 6#, and contradicts any ideas of shorter draw and other inefficiencies, which could otherwise be associatred with the new spine issue. It is likely as you say.......it wants what it wants. Fortunately there is more art than science to this obsession!
Maybe check the string alignment with each set of limbs-is it possible that the string lays 'right' with the heavier limbs?
Bjorn:
I'm not sure what you mean by string alignment. Sorry. My friend was watching my draw to make sure I wasn't short-drawing the heavier limbs. That wasn't an issue.
If you'd explain string alignment, I'd appreciate it. Short but sweet is fine!
Are the strings the same (# or strands etc)?
Could you possibly have more string sliencer on the string for the heavier limbs?
Just a couple more things to look at.
You may be getting a cleaner release with the longer bow. I also agree with A.S.
GMMAT, it is what it is and go with it. You got the speed increase from the heavier limbs; and you bare shafted with the proper result-spine is just a number anyway.
Good luck hunting and don't forget the pics! :thumbsup:
Same string. Both are the ones that came with the bow (both were new in the last few weeks....as I put the new strings on when I got it).
I put yarn on the heavier limbs.....and the lighter limbs have beaver balls. If anything, I'd say they're similar.
I appreciate it! Really. We went through these things while tuning.....so we're thinking alike.
It's just interesting, to me. I'm still new to this aspect of trad. archery (new to all of it, actually). I can't figure (in my head) if the added length would affect this. I can (in my head) understand a heavier (mass weight) bow not clearing (I hope that makes sense) as fast as a lighter bow (on the shot). I can imagine a more stable bow (not moving on the release) requiring a weaker spine.
Thaks all....and Bjorn....I have my eye on two deer. If I'm successful, you won't have to worry about a photo!....lol
Thanks again, guys!
Orion is right. There is nothing at all surprising about this. I shoot Heritage CX 250 Classics through my 57# Silvertip and I could take these same arrows and shoot them through any lighter bow. Arrows and their specific spines have a fair range of bow weights for which they will work through, and isn't that nice.
http://www.carbonexpressarrows.com/images/2009_Arrow_Guide.pdf
Carbon Express arrow chart says HE 250's will work through a 50# or 56# bow at your draw length.
Different tiller, core materials, Maybe even a cleaner release with the heavier weight
The bow was ordered with both sets of limbs (both tillered by Dave...but I guess it could be different....at some minute level).
THE ARROWS that fly correctly from the 50# limbs......are TOO STIFF for the 56# limbs. Sure the 250's will work for both.....at some length and with some amount of tip weight. But not the same arrow (I would be VERY surprised).
I'm MORE surprised it wants a weaker arrow, though.
Have you tried the exact same arrow (you said you would be surprised) through both limbs?. What indicators are telling you those arrows are too stiff for your 56# limbs, are you sure you don't mean they're too weak? I do a lot of bare shafting testing with my Silvertip, using these arrows, amongst many others, so I sincerely mean to offer some help, if I can. I have found that the CX Heritage shafts tend to be weak, per they're claims. I sent HE 150's back to 3 River's for this very reason.
Kris:
Yes. Too stiff (for the heavier limbs). That's what is perplexing. I bareshaft tuned the 50's a couple weeks ago. The bare shaft that flies like a dart thtough the 50#ers is 30-1/8" long BOP with a 175gr. FP. THAT arrow shows STIFF out of the 56# limbs. When we went to the 31" arrow (everything else remaining constant, arrow-wise), it flew great. Now....Have I tried the 31" from the 50#ers? Nope. They could very well fly great.
Jeff,
This whole thing can kind of become a word game, if you know what I mean? I was actually curious to know what you see when a bare shaft tells you it's "too stiff", specially.
So you added 7/8" to your arrow going from a 30 1/8" arrow to a 31" arrow, which slightly reduced the dynamic spine of that shaft, and that longer bare arrow now flies through your 56# limbs, whereas the 30 1/8" did not, correct? And both these shafts had the same aluminum inserts with 175 grain FP's.
You are going from a 60" bow to 62" bow, which requires a different string. Is your 62" 56# limbs tuned to these shafts as well as your 52# limbs are? Different limbs will require a different brace height, nock height, etc. so tune the heavier limbs like you intend to have these shafts fly through them, at least.
You said you are drawing the two bows exactly the same length, just so you know that you are in fact, drawing the weight you think you are. Often people going to a heavier bow draw shorter.
My point being, that what you may be calling "too stiff" is a function of variables that are not 1:1 between different weight limbs. Your observations of "too stiff" maybe a difference in tuning or a misdiagnosis of "too weak". I don't know you or your depth of experience with trad. gear and mean no disrespect by suggesting any of these things. They are just some of the things I think about when tuning, plus a whole bunch more. I have been shooting traditional for 35 years.
I went out tonight with my 57#@28" Silvertip TD, CX 250 Heritage shafts cut 29.5" BOP to trough of nock, w/50 grain brass inserts, fletched w/3, 5" parabolic fletches, tipped with a 125 grain Judo and had exceptional arrow flight, nothing I would come close to calling over spined or "too stiff". I have also bare shaft tested the same arrow with similar results. This means nothing for you and your unique style of shooting but is a similar comparable numbers wise.
A shaft I've had great luck with for this weight Silvertip is the Beaman MFX 400's. You can bare shaft these out to 25 yards with perfect arrow flight with 100 grain brass arrow inserts and 175 grain FP's. A highly durable and accurate shaft as well.
Call me or write if you would like to talk further, sorry for the long response. There are many variables that affect tuning and it is not often correct to attribute what we see, to one variable. Always ask yourself more questions.
Good luck
If you weren't sure you were not drawing the heavier bow less, I would have said that's your problem.
I bet it is the extra length of the 62" limbs. They are going to have an "easier" draw cycle and you will have a cleaner release both from the extra length and poundage.
Jeff,
This whole thing can kind of become a word game, if you know what I mean? I was actually curious to know what you see when a bare shaft tells you it's "too stiff", specially.
So you added 7/8" to your arrow going from a 30 1/8" arrow to a 31" arrow, which slightly reduced the dynamic spine of that shaft, and that longer bare arrow now flies through your 56# limbs, whereas the 30 1/8" did not, correct? And both these shafts had the same aluminum inserts with 175 grain FP's.
That is 100% orrect.
You are going from a 60" bow to 62" bow, which requires a different string. Is your 62" 56# limbs tuned to these shafts as well as your 52# limbs are? Different limbs will require a different brace height, nock height, etc. so tune the heavier limbs like you intend to have these shafts fly through them, at least.
Not sure what you're saying (I admitted being new to all this). The string is different, of course. We adjusted nock height when we bare shafted. Same string make-up (both from Dave). I don't shoot the same shaft (length) from the different limbs....so it's hard to say if they're tuned to the same shafts. They're both 250's but you know the difference in length I mentioned.
You said you are drawing the two bows exactly the same length, just so you know that you are in fact, drawing the weight you think you are. Often people going to a heavier bow draw shorter.
And I understand that. If I didn't have my buddy there watching, I wouldnt be so sure.
My point being, that what you may be calling "too stiff" is a function of variables that are not 1:1 between different weight limbs. Your observations of "too stiff" maybe a difference in tuning or a misdiagnosis of "too weak". I don't know you or your depth of experience with trad. gear and mean no disrespect by suggesting any of these things. They are just some of the things I think about when tuning, plus a whole bunch more. I have been shooting traditional for 35 years.
No offense taken!! I'm VERY new to all this, but my friend Page is a state champion shooter....and an accomplished personal bowyer. He's won with the bows he's built. He's the most knowledgeable traditional mind I know & have access to. He's not all that perplexed. I just wanted to understand it better.
I went out tonight with my 57#@28" Silvertip TD, CX 250 Heritage shafts cut 29.5" BOP to trough of nock, w/50 grain brass inserts, fletched w/3, 5" parabolic fletches, tipped with a 125 grain Judo and had exceptional arrow flight, nothing I would come close to calling over spined or "too stiff". I have also bare shaft tested the same arrow with similar results. This means nothing for you and your unique style of shooting but is a similar comparable numbers wise.
One thing Page taught me is.....Brass inserts change everything. I used to shoot 50gr. inserts....and then 100gr inserts. I can tell you from experience that you can take 2 identical 250's cut to 30" and put 175gr. on both (one utilizing a 100gr brass insert and the other utilizing a normal insert and a 160gr head)....and you're subject to different flight/spine characteristics. I just went through this with a set of arrows I now find useless!!....lol
A shaft I've had great luck with for this weight Silvertip is the Beaman MFX 400's. You can bare shaft these out to 25 yards with perfect arrow flight with 100 grain brass arrow inserts and 175 grain FP's. A highly durable and accurate shaft as well.
Call me or write if you would like to talk further, sorry for the long response. There are many variables that affect tuning and it is not often correct to attribute what we see, to one variable. Always ask yourself more questions.
Good luck
Thanks so much for the response. I agree that EVERY little things affects something.
Tried it without the quiver yet??
Eric
Hey Jeff
Thanks for your nice response; you answered things in a very logical way.
Page sounds like an outstanding resource, he no doubt, knows what he's talking about. I would utilize his expertise, as I'm sure you are.
So, I know more about where you are coming from, you are not far off on anything, for that matter. What are you actually having a problem with?
You should be able to get good/great arrow flight with the 30 1/8" fletched arrow with your heavier limbs as well as your 50# limbs.
Which brings up another question; why are you shooting two different length arrows, to compensate for the BH, or, is that what you did to tune that shaft to your heavier limbs (i.e. left them longer)?
I have never been a fan of cutting arrows to tune them, I know what arrow length I need/want, and go from there. A person still has many tools to work with w/o cutting, provided you've started with shafts that are spined in the ball park. I would pick one arrow length that works for you, say 30 ½" and use other techniques to tune your shafts to the bow.
I wouldn't worry if you can't get 'perfect' bare shaft arrow flight (but it is a huge plus). I hate to say it, but yes, fletching can/will correct for it. I have found the CX Heritage series to be more difficult to tune than other carbon shafts, but admittedly have not used them as extensively either. I think it might have to do with their wood grain wrap (purely speculation and my unproven opinion).
There are all kinds of tricks for getting an arrow to fly, and you touched upon one when you mentioned FOC or weight FRONT OF CENTER or FORWARD OF CENTER and that involves manipulating the amount of the weight at the front of your arrow. It does several things and Page can probably tell you all about it. Yes, it will change the dynamic spine and it is the rage right now for increasing penetration and improving arrow flight, in most cases. It is a very useful and important tool to know something about.
There is good info you can read on all of this. One resource is here on TRADGANG and is in the Ashby articles post by Rob DiStefano and is on the Main Forum. You can write me a personal email address if you can't find that specific info, as there are many updates to pour through.
Another really excellent learning resource is by O.L. Adcock, and he'll explain more about what 'over & under spine' means plus a ton more. A must read!
http://www.bowmaker.net/tuning.htm
This is all fun and once you get the hang of it, is totally addicting; you'll love challenging yourself to tuning arrows and bows. I have not even scratched the surface on what you can do to make all this stuff work for you. Welcome to the Club!
Sincerely - Kris
just an idea, what do you think about that: your heavier bow is longer, your fingers are less pinched by the string, your release has become clearer, the resulting paradox is less important...you can shoot a weaker arrow !
The proof will be the next step in the tuning process. Leave the bareshaft testing behind now that you are close and go to broadhead testing. Do the same as with bareshaft only shoot your broadheads and target points and compare group location. If they shoot together out to 40 yds or so. You are tuned and ready to go.
Mike
Thanks guys. I ordered BH's Thursday. We'll see. I did orded 185gr heads. Looking forward to building my first "real" trad arrow, myself.
I appreciate all of your replies.
I agree with Wingnut. The broadheads will tell the real story. I use the big 200 grain Ace as my broadhead for testing. If it flies good, I figure I am OK as long my finished point weight is within 10 gr plus of minus. Of course you may have to do some mixing and matching of inserts, adaptors etc. to get the right weight combination.
Jeff, the quiver can most definitely make your bow need weaker spine. I've seen it many times, and I don't use a bow quiver because of it.
My theory is that the heavier mass of the bow with quiver added (and your 62" limbs are likely heavier, too) makes the bow move a little more slowly to the side at the shot, so the arrow has to bend a little more to clear the riser. Anything that affects the overall mass of the bow affects spine to some degree.
Bows that are made less centershot (by building out the strike plate) require less spine than they did before. Likewise, bows that are made heavier in mass (by adding a loaded quiver or any other kind of weight) may require less spine than before. It all has to do with the shaft clearing the riser during the dynamic movements that take place when a bow is shot.
It follows that lighter mass bows are more sensitive to the addition of a quiver than heavy mass bows. A person shooting a bow that's relatively heavy in mass may not notice the effect of adding a quiver, but a person shooting a lighter mass bow probably will.
Don't get me started on string silencers... :)
Thanks, Don. I stated the EXACT same theory as yours when I was discussing this with Tommy (Rocky Mtn. Specialty Gear) the other day. It made sense in my mind. I've got some brass knobs coming for a new Silvertip riser I have on order.....and I'm betting even that causes me to have to shoot weaker spined arrows. The extra riser length will also make a 60" bow a 62" bow (which will also make the 50# limbs 48#'s). I'm anxious to see how it turns out.....and to stop the tuning merry go round.
In my opinion Bjorn got it right a couple pages ago when he ask if the string aligned the same. He was talking about the center shot. If the string aligns a little farther to the right of the side plate, it will affect center shot and require a lighter spine. The opposite is true if it aligned a little to the left. The difference would not have to be very much to make the spine change.