Spine located located shaft, why?

Discussion in 'General Crossbow Discussion' started by Vital Limits, Dec 16, 2017.

  1. Vital Limits

    Vital Limits Member

    Thanks Xcal!
     
  2. Vital Limits

    Vital Limits Member

    Its not a matter of it being fast , although she is moving I'm sure. When you have better components and building methods better efficiency / lift come into to play, simply said the arrows fly better since they are better stabilized shot from a more efficient bow.. Example when the Aero Bolt II G was shot out of the Scorpyd V-tek 440 X bow, out of the gates that is running 185lbKE,,, but still jamming 350fps @180lbKE still at 100yrds.. That is only about a 3% efficiency loss and that is Scopryd numbers on the testing if I recall right..

    Many will equate fps as a means to gains, but fps is not the only equation. How the arrow is stabilized through through the entire shot process and how it delivers its retained energy to the target downrange where it counts. Its not a surprise that a vertical bow being built with good arrows can have minimal drop on a 20 yrd pin out to 40 yrds and still be within the kill zone of the deer..
     
  3. Oppie

    Oppie Active Member

    Nice. I always thought two arrows of the same weight & velocity shed kinetic energy an velocity at the same rate regardless of the brand or method they were shot. But a arrow only losing 5lbs of kinetic energy over a hundred yds is impressive.
     
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  4. Vital Limits

    Vital Limits Member

     
  5. Oppie

    Oppie Active Member

    Got Ya, Scorpyd + better arrows = better flight, less energy loss due to wibbly wobble :D more energy, we all need more energy.
     
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  6. MI_Bowhunter

    MI_Bowhunter Member

    It was very important with wooden shafts, moderately important with aluminum shafts and a probably a little less with the more modern carbon.

    I personally do not test mine and am happy with my groups out to 70 yards.
    I do find the discussion interesting, and much like reloading metallic cartridges, every little seemingly inocuous thing has an overall impact on the end result. How much depends on a lot of other factors as well as the individual demands of the shooter.
     
  7. Vital Limits

    Vital Limits Member


    You're right, other factors are involved.. I always say there are 3 over tuning factors, the shooter, the bow and the arrow. When you have a very well tuned bow and have good shooting form, the mistakes are not as amplified. Most hunters including myself do not have shooting ability like a Levi Morgan who can shoot about anything handed to him, yet they still do a lot of tuning though. For the most part this will help the average guy be more consistent as without the knowledge of some of the pro shooters and or 30K+ slow motion camera set ups first stages of launch cycle are about next to impossible to perfect.. The spine indexing is one of the aspects, another in the Concept 1.0 and 2.0 system .. Not only will the arrow leave on a consistent bending point ( first dynamic bend ) it will stabilize better and minimize the errors that can occur in launch helping deal with inconsistency's of something like nock travel.

    The Cross bow imo is even more critical for spine locations not just because of consistency, but when the spine location is face properly during launch the pressure will be less on the rail or at time might be zero and this will be more ideal complimenting the null point of the shaft on the rail
     
  8. xcaliber

    xcaliber Active Member

    I have tuned bows for years, and have personally owned about 18 different bows, 15 of them high end Mathews, Bow Tech, Hoyt, and PSE as well. I disagree that anything you do will compensate for bad form. If the shooter has bad form, punches the release, has panic issues, nothing can be done to correct those conditions with equipment adjustments including arrow mods. Shooting well with any hand drawn / held bow begins with proper form, without that, the foundation crumbles rather quickly.
     
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  9. xcaliber

    xcaliber Active Member

    I have taught / trained a few newbies over the years. I make them use dead releases for a few sessions to make sure they are not trying to use a bow too heavy in draw for them, and insure that the draw length is correct. Usually with a new shooter I start them out with a draw length at least 1" too short. It makes them uncomfortable in some instances, but they get used to the hold, and line up with eye / peep really quickly. I have found over the years that the big box stores have people there selling bows with very limited experience, and training. I'm no longer an expert in this field, and probably forgot more than most will learn. I encourage you to train newbies, not only do you get the pleasure to bring in new people, but you get to revisit the things you have learned over the years. I personally wish you the best on all your endeavors.

    Dan
     
  10. Oppie

    Oppie Active Member

    X2. Love taking the newbies, whether it be fishing or hunting, I'm in :), I come with snacks....
    There's a whole new breed of archer's coming and our outdated toys won't be enough.
     
  11. Vital Limits

    Vital Limits Member

    I'm not doubting that you've tuned bows for years and not saying that I have the cure for bad form. What I'm saying is some of the in inefficiencies in the bow and or form can be reduced to a degree to in the arrow flight, but if you drive your truck off a cliff, nothing will help you, but having suspension to soak up some of the bumps on the road can help a little..

    Since you are a Black Eagle Dealer and been around for years, I'm sure you know of Infinity archery.. Not sure if you seen it, but Rod did a shaft build, spine indexed with AV2 vanes, Firenock nocks, Firenock Concept 1.0 in Black Eagle Rampage arrows. Out of all matched weighted arrows the next closest fps arrow was still behind 29fps slower at 50 yrds. The difference is the concept arrow ( " The Boom Stick ") was a better stabilized arrow, more retained energy downrange where it is needed since oscillations down are minimized.. The Slow motion video on his page of the launch cycle of the arrow was cool too.. If you dont know who I mean,, just ask Jason..
     
  12. xcaliber

    xcaliber Active Member

    I have to get up on things Vertical honestly. I do use Carnivore on my Hoyt, and PSE, and the Kid uses them with his Martin. I'm a simple guy, not very high tech compared to what these younger bring to the game in the last 6 years or so. I will say that in all the years i have been involved in archery, form was the main thing to learn / teach newbies. In the 80's & 90's if you had good form you could get great results with moderate equipment. I had a Browning as my first compound bow, and by today's standards, and in comparison to what to i shoot these days I would be better off throwing that bow at deer.:eek::p Honestly, you're probably way more up on things than I am, but I still think that good form is top priority when shooting any hand drawn bow.
     
  13. Vital Limits

    Vital Limits Member


    I think you may be takeing what I said wrong thinking better parts means form is not longer needed, That is not the case as I think all 3 areas Shooter, bow and arrow are to be in tune.. That being said as the better shooting form can make a shooter get away with a littler lesser efficiency as you mean ( which I agree ) the better parts can aide the other way, that in some of the errors of shooting for,, meaning inefficiencies from shooting forum and or bad components can be dampened to some degree because the arrow is better stabilized and those other imperfections are not as extreme. In short the effects are less.

    Not sure if I mentioned it, but a hard thing to do is to try and perfect launch. It would be most likely a pro level shooter and or someone who had the knowledge and had slow motion cameras.. to see how the arrow is coming out on the bow which helps with down range efficiency.. Now , since I am not a pro or own a 40K slow motion cam set up I have to think how I help someone have a more forgiving launch cycle not having the knowledge in form or cost of camera,, its through better components and for years the archery industry a s a whole really never put a lot of thought in arrow components.. Using Concept 1.0 and now 2.0 we can now calm down what happens in launch since the arrow flex is better stabilized yet still acting as one, which is key based on tolerances with glue.. After seeing how Concept 1.0 worked in slow motion concept 2.0 followed shortly after, my first test result out of the gates and at 30, 40 and 50 yrds was about a 9.5 percent efficiently loss. Which from what Rick Mckinny tells me it normally would be more like 20-30% at 30 yrds.. The concept system can be a big benefit for the average shooting especially with a bow built with titanium hardware and titanium rest since the null point of the shaft is now broadened.. The shot cycle is more forgivable..

    AOA using the concept is also more ideal since oscillations can be minimized from say 15-20yrds down to 9-12ft.. Meaning more ideal point of impact vs just trying to find consistency in flow direction.. It is a more ideal close range arrow..

    Below is pic of arrow dynamics, the concept 1.0 does same thing just through components.. The 2.0 which is not in pic now helps the back of the shaft in the same manner.

    The thing people dont really consider is now through building methods and better components an economy based shaft like the Outlaw can out perform the other factory built higher end shafts in its class, for less money..Something arrow manufactures dont want to hear..

    Arrow engery 2.jpg
     
  14. Vital Limits

    Vital Limits Member

    Those tube on top of pic are the concept system parts with double shoulder inserts.. They are what goes into the front of the shaft.. Firenock.jpg
     
  15. Stalker

    Stalker Member

    I built my own spine tester and spine index my own crossbow shafts. I do see a improvement with groups. From everything I read before hand (hype imo) I was disappointed the improvement was not greater.

    Imo spine location is not as critical with crossbow arrows.Due to the fact they are shorter, have a heavy spine,ride a rail at launch and don't have near the oscillation. Here is a video of some old Executioner shafts I spine indexed.Shot from one of my slower bows. They had hundreds if not thousands of shots on them before I tested and refletched them. I'd say the overall group improved about 1-1.5" at 30 yards.It basically brought 2 fliers back into the group as well as tightening up the rest a little.
     
  16. Masboy

    Masboy Active Member

    I don,t have near the problem with a vertical bow for arrow poi as I do a crossbow. vertical bows are not shot off sand bags either,mabye I,m not a good enough shot to tell:rolleyes:

    I find with recurve crossbows it,s more how you hold an shoot the bow than spine or anything else with a well made good quailty arrow. they do recoil an you must let it recoil just like a spring pellet gun for consistent accuracy. my arrows shoot much better for poi when the forends not sitting directly on the sand bags or squeezing the bow tight. ok with my hand on th bag an the forend just laying in my hand not gripping it tight.

    I use the artillery hold just like I do my spring pellet gun.i have had arrows I shot off bags that the poi was off I thought were no good an then shot using the artillery hold an right there with the others.I find a smooth launch,holding it the same a must for for consistant accuracy with a crossbow . if you shoot bare shafts you will find that out quick .i still turn my bare shafts when needed to fine tune before fletching. works for me
     
    Last edited: Dec 22, 2017
  17. Vital Limits

    Vital Limits Member



    First of all, cool video! I think when people do videos and post them on public media like YouTube can be a great learning tool.. Thank you for the video.. You made some great shots.

    The groups being more consistent is a huge improvement imo to the pocket cost alone, who wants to buy " fliers " , not me..... Let say you buy 1 doz factory arrows of anything, likely less than 50% would be match with each other. With the " aim small , miss small " theory out there which I like implies archery is a pin point accuracy sport the other shafts as you mentioned are " fliers " therefore imo I would never take an arrow out in the woods that I knew had accuracy issues let alone want to pay for them.. That being said it would be more economical to buy a dozen spine index arrow vs non indexed.

    The fact that a bolt rides the rail and is shorter is exactly why you would want a spine index arrow with a more ideal spine,, " extra stiff" can be bad if applied wrong since the bolt is more ideal if it can react to the shot ( flex at the natural bending point ) .. A spine indexed shaft as I said in original post can relieve pressure and or at times could have close to zero contact with the rail.. Having the theory of stiffer, more contact with the rail produces accuracy is fallacy in the sense that contact pressures with the rail can cause greater friction which will make the shaft resonate vibration more ( expend energy ). Not saying you cant " group " an arrow, but just to say an arrow can group so it is just as just as good becomes a little misleading. A Lamborghini and a Prius can both cross a finish line,, but there is a huge difference in how fast they got there and who got there first.. When I start hearing broad head issues of say mechanical not opening , close range shots only going in a few inches and hunters loosing deer, the inefficiency issues start to ring loud and clear and there are a lot of them..

    In a nut shell, the gains offered in spine indexing whether or not it is worth it to a person is up to them, like I mentioned in earlier comment I think some shooters are happy with shooting a paper plate at 20 yrds while others do whatever they can to hit a dime at 50..
     
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  18. xcaliber

    xcaliber Active Member

    Nice video, and great shooting!
     
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