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SPINE LOSS CAUSES

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Old 02-10-2006, 08:31 AM
  #11  
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Default RE: SPINE LOSS CAUSES

I've just got one thing to say: I wished I lived closer to Len!
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Old 02-11-2006, 07:03 AM
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Len, I am a little confused when you say a bullet hole indicates that the arrow is not flexing. Every slowmotion video that I have seen shows the arrow flexing in a wave like motion from side to side (might not be the correct way to describe it). The purpose of tuning the bow is to minimize this flexing. Thats why we have different spine weights for different draw weights, ie. to control the amount of flexing. I am not trying to dispute your word so please correct me if I am barking up the wrong tree.

GGBH
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Old 02-11-2006, 07:12 AM
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Len, though I am not an expert in bow setup and tuning, I thank you for your post supporting paper tuning.

I like to tinker and paper tuning is most important to me.

I also like to bare shaft tune -back to about 20 yards. (You must be sure you are not torqueing the bow in order to use this method).

I find if I can get my bare shaft on a good straight flight, I can get all my shots - with the fletched arrow (field points and broadheads) -grouping together.

Whats your feeling on tuning with a bare shaft?
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Old 02-11-2006, 07:22 AM
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You all talked about varying spines in a dozen arrows and paper tuning.
How can you paper tune the whole dozen if their is a difference is tunning
to one shaft not going to throw the other ones out?Shooting a bare shaft at 20 yrd?
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Old 02-11-2006, 09:27 AM
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Here are some answers to some of the questions.

The distances checked are usually from 10 yards to <1 yard. If you want, checking out to 20 or 30 yards can be done. This is usually necessary if you 'see' an arrow that doesn't 'fly' right. If you get a tear at these distances, I've seen where refletching the arrow solves the problem. This is not always the case, but is the first place to start with an errant arrow.

The old 'slight high tear (left or right)' was really (IMPO) a way tokeep the arrow/fletching from contacting the forks on the rests. If you're using a drop-away or containment rest, you do not want to see this. Keep in mind that containment rests can and will give you a 'false sense of tune'. This is a prime reason why they especially should be tuned at varying distances.

A bullet hole doesn't mean that an arrow is not flexing, it means that you've hit a 'node' where the arrow is going through the paper 'straight'. Remember, when an arrow flexes it usually does soin a + or - state around the centerline of the arrow. If you 'catch' it at that 'neutral' point at varying distances, you've 'neutralized' the flexture of the arrow to a minimum and therefore achieved minimum KE loss. You've also kept the point from straying too much. This will help tremendouslyingetting field tips and broadheads hitting in the same spot. In the case of BHs, any time a BH tip leaves that 'neutral zone' it can 'grab air'rather than cut through it. Stick your arm out the window atabout 60 mph and see what happens when you do ordon't keep your fingers/hand pointed directly into the wind.

By picking the right spine, without getting into too heavy a spine, we minimize the bend while maximizing the speed. A lot of tournament shooters will tell you that they can shootheavily spined arrows with great success. That's true to a point; but, they also loose a lot of speed. Now don't get me wrong, I'm not a speed freak; but, you don't want an arrow that is too heavy (or too light)for the game you're after. Think about it.

The ONLY time I would consider doing 'bare shaft tuning' is if I'm absolutely sure I've got a tuned bow, arrow, and archer! If that arrow has the slightest 'bend', is not the right spine, or has a loose/weak nock, then it won't 'bare shaft tune' right. If your bow has a bad string, worn bushings/bearings, or several other types of problems, it won't 'bare shaft tune' right. If you're not a repetative form shooter, it won't 'bare shaft tune' right. It gets back to my 'Tuning Trilogy' seminar.

When I tune a customer's bow, I always ask for a 'straight arrow'. That's my starting point. It is with this one arrow that I determine whether or not it's the right spine. If the bow tunes with that arrow, then I've set a baseline. I tell my customers that all arrows are NOT the same in any given batch. The degree of 'yield' will vary from batch to batch and from manufacturer to manufacturer. If they want me to 'tune' every arrow, I will do it; but, that will cost a lot more because it takes time - and time is money. Sorry guys and girls, but my family likes to eat too. I've had customers who wanted all their arrows tuned with FTs and BHs. If that's the request, it can be done. If you think that tuning one arrow gives you a tune for every arrow in your quiver, you're wrong. Once you weed out the ones that won't tune, use them for practice. [:@]
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Old 02-11-2006, 09:44 AM
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Default RE: SPINE LOSS CAUSES

This goes back to the question about every arrow.So get a arrow
shooting a good hole then shoot the all thru paper to see which ones dont and disguard them or use for practice?
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Old 02-11-2006, 08:52 PM
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I agree with alot of what Len says. I myself am a bareshaft guy, generally I don't paper tune, I bareshaft. What I have been doing lately is this.

I take every arrow shaft I bought, install nocks, inserts and fletch 3. Then I get the bareshafts and fletched shaftsshooting the same at 30 yards. Then I take and make the 3 fletched shafts bareshafts again. I shoot every arrow into a group at 30 (all bareshafts). If I shank one I go and pull it right away. Any arrows that are out of the group are shot again at another target, if they hit good the next two times I keep them if not they are junked.

Bareshafting and paper tuning tell you the same thing. I like bareshafting because it seems to be more precise. I can have a bow shot a bullet hole at 5 feet, and the bareshaft be off by 8" at 30 yards. I get the bareshaft flying good, go and paper tune and it is still a bullet hole.

My GAURANTEE, If I bareshaft tune a bow, and the broadheads spin true they will fly to the same point out to 50 yards (Never tried further).
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Old 02-12-2006, 06:54 AM
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Default RE: SPINE LOSS CAUSES

This is some great information, especially for inexperienced tuners like me. Thanks to Len and others for posting this.

Now for a reallystupid question - Why worry about spine?

In the days when the only available material for arrows was wood or bamboo, arrow flex was a fact of life and archers learned to deal with it byadjusting spine to the archer and the bow.

Now that we have carbon composite arrows, why not just make them all stiff enough that flex is minimized to the point that it is irrelevant?

I'm really not trying to be a smart a$$, just asking an honestquestion that I've wondered about for a couple of years.

Thanks,
Allen
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Old 02-12-2006, 07:16 AM
  #19  
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Default RE: SPINE LOSS CAUSES

By picking the right spine, without getting into too heavy a spine, we minimize the bend while maximizing the speed. A lot of tournament shooters will tell you that they can shootheavily spined arrows with great success. That's true to a point; but, they also loose a lot of speed. Now don't get me wrong, I'm not a speed freak; but, you don't want an arrow that is too heavy (or too light)for the game you're after. Think about it.


Allen:

Let me expound on the statement above. There are cases where an overspined arrow can really hurt you both in arrow flight and yardage 'estimation'. Depending on the design of the bow, which relates to arrow flight, there are some bows that are more'sensitive' to too much spine. As I have stated many times, it is better to have an overspined arrow rather than an underspined arrow; however, you've got to weigh the benefits and shortcomings dependent on your bow, your game, and your skills. I hope this helps.
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Old 02-12-2006, 07:32 AM
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Default RE: SPINE LOSS CAUSES

Good Morning Len,

Thanks, that does help. Now for one other stupid question - how do you know when an arrow is spined correctly for a particular set up?

The charts are easy enough to read, but they are limited in the information that can be factored in. The computer programs such as OnTarget are impressive, but they sometimes seem to take too much information into consideration.

If I buy a dozen arrows that the charts and the computer says are right for my rig, is there a way to make the smalladjustments length and point weightthrough field testing?

Thanks,
Allen
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