June 27th, 2005, 12:08 PM
Short vs long arrows?? Opinions/Facts
So, it may have been said before that long arrows fly better! But why?
The answer to this I do not know, so that is why I am posting this for people to submit their experience/knowledge, so that we all may learn.
All things being equal, (FOC, Dynamic spine, fletching, nock type, an all other variables being the same) an arrow that is lets say 26 vs 29" should shoot the same...??? I know of no law of physics that stated that there needs be a specified distance between the point of the arrow and the fletching. I can only figure that for a person faced with a choice of the same arrow, cut short or long (let assume that the spine of the arrow is appropraite in both cases), will only benifit from the longer arrow because FOC in most cases will be better. But, thats just a 2 second analysis
Anyone out there that has specifically tried to answer this question for themselves by testing or math magic, please respond, wanting minds must know
June 27th, 2005, 04:43 PM
I have a short draw length. I have heard this talked about before as well. Like you shouldn't shoot an arrow shorter than 26 inches or something like that. Well the proper length arrow for me is under that to begin with.
I tried longer arrows, I didn't see a big difference other than the arrow was heavier. I have also shot 21 inch X7's indoors before. I shot the same with those as I did anything else. I even put 5 inch feathers on them once. Looked goofy as all get out, but they flew pretty well.
Now for long distance type stuff a longer arrow might be more arrowdymamically stable. However I have not seen a difference out to 50 yards or so.
And actually there are some advantages to shorter arrows. For one the tolerances are better. A shorter arrow will have less variances in straightness, spine and weight compared to say a 30 inch arrow.
Now if you didn't have fletching, or inadequate fletching, then length might make a difference. But with proper fletching it shouldn't make a difference, that is what it's there for after all.
Keep in mind I am not an engineer, I am only going by what I have tried. Sometimes I wonder if some of this stuff is not just an excuse for someone not shooting that well?
June 27th, 2005, 06:36 PM
I think the easiest way to explain arrow length and accuracy would be to discuss nodes. Arrows have a forward and rearward node that the arrow oscillates on when released. The slower the oscillation the better recovery time your arrow will have so with that said....
Originally Posted by philipdimondo
Lets define things that would dictate where the nodes are and what the frequency of oscillation would be:
Arrow shaft material
Nock end weight
Now lets look at things on the bow that can also effect the frequency...
Rest position where it relates to the frontal node..
Rest position as it relates to tune
Nock travel of the bow
As you can see there are LOTS of things that can effect how an arrow oscillates and the shaft length isn't the largest determining factor. Personally I would stay away from relativley short stiff arrows with small fletch and little tip weight.....
Ultimate longer range archery requires that an arrow oscillates relativley slow (I don't know the exact frequency...feel free to chime in) for good recovery and the above listed arrow would not be a good candidate.
June 27th, 2005, 06:55 PM
Greater mass, the same frontal area, and a better lenght to diameter ratio the longer arrow has it advantages.
June 27th, 2005, 07:45 PM
Hm but why do I often hear people cutting their arrows 1'' from the farthest point of the arrow rest - seems like they are too keen on having complete arrow not pass beyond riser...?
He who controls the past commands the future, He who commands the future, conquers the past.
June 28th, 2005, 04:05 AM
There is a big difference, in my opinion, between an arrow for indoor 20 yards and an arrow for outdoor till 100 yards.
TAP comments are totaly correct and they are aimed at the short indoor distances, when we talk about long distances the speed at which an arrow recover is less important IMHO.
When shooting long distances it seems that a short arrow (1" to 1/2" pass the rest) with a heavy point and the right spine is the best compromise to get me the smaller groups.
June 28th, 2005, 10:36 AM
I am certain there are published physics to fully explain this situation. There are there are certainly those who will have differing opinions to any given statement. So from what I have learned in my "fiddling" and also reading is that the slow arrows are better indoors because you want the extra"time" for the arrow to correct the Nodular oscilation referrered to in another post. Obviously the line cutter's are out there to get those extra points. However, bigger is usually heavier. Rifles are more accurate than pistols and I expect that relates to mass an moment arm. I have read that the 20 yard distance (18 meters) is tough because the arrow has very littly time to allow the fletching to stabilize flight. I have a 32" DL so I usually have 28-30" arrows. In some cases (bow weight) I can't shoot certain arrows unless they are at least 28" or else the spine isn't stiff enough. The usual problem is trying to hug the 5gr/lb thing to maximize speed for more forgiving flatter trajectories. SOme are not aware that their screaming meemie (300+) arrows can also degrade accuracy since it has a tendency to magnify shooter flaws. Speed is not an issue indoors and it may sometimes be surendipitous as some want linecutters for the size edge and are actually realizing accuracy improvements as a function of arrow weight and length. I own an Accutec Bow which can shoot any arrow from full size down to their unique 4" dart like hunting arrow and it is amazing accurate. However, their design transcends the whole spine issue.
June 28th, 2005, 11:57 AM
Roger Willet set the record in grand fashion at Redding a couple years ago with arrows that couldn't have been over 26". As a rule of thumb I think arrows with shorter length tend to stabilize better with a little more FOC than normal. The longer arrow has the surface area and length to stabilize it where the shorter one does not.
Think of it as throwing a short or a long javelin
June 28th, 2005, 12:01 PM
So far all that I have read in your responses only verifies the node theory and that the lenght alone is not the determining factor. FOC and fletch area also play very critical roles in determining how well an arrow will recover and fly.
Bow tune and rest position also in my opinion play pretty critical roles in the overall flight and forgiveness of your arrow selection.
June 28th, 2005, 12:13 PM
A javelin does not have fletchings. With proper fletchings it should not make a difference. You can theorize and do all the math you want. That doesn't mean it actually works. I went from 26 inch arrows to 21 inch arrows. I did not shoot any better or worse. The only thing that screwed me was the tiny diameter of the arrows. And the fact that I had to shoot a 3 inch over draw probably didn't help much either. Didn't seem to hurt either though.
And as far as the vibration factor goes, wouldn't that mean that aluminums are better than carbons since carbon arrows oscilate different?
I think it's like every thing else. It is just something else to blame. Put them all in a shooting machine and see what happens. I would be courious to see the results. I have read of too many people with bad set ups winning shoots to believe it makes that big of difference. In the end it is the person releasing the arrows that makes the difference.
I think if you are obsessing about the length of your shaft (sounds kind of dirty doesn't it?) you are psyching yourself out and you are screwed before you even step up to shoot.
Just my opinion though.
Last edited by Paul Mohr; June 28th, 2005 at 12:16 PM.
June 28th, 2005, 12:36 PM
Let's throw in a little torque value. More or less affect on long vs. short?
June 28th, 2005, 09:46 PM
so, the answer is
Hey, thanks for all those who replied and put out your experiences so we all may learn.
Personally I am torn between shooting a 500 series GT PRO @ 27" or a 600 series GT PRO @ 26" (Both borderline on the GT charts)
I know that 1" will likely not make a noticible difference, however, I really just wanted to see if anyone had 2 pennies to put down on this age old question.
At a quick glance, long or short, you have to have the right spined arrow, FOC and nodal point...
Concerning nodal points, now what effect does a drop away have on tuning for nodal points?? I know by powder testing that my rest is gone within the 1st 3" of the arrow after the shot (Or my arrow is skipping up off the rest (Not sure of that), and to boot my arrow rest is just a little carbon prong, I cannot imangine that the arrow is much affected by the arrow rest at all.
Whats the concensus out there on drop aways?
June 28th, 2005, 09:54 PM
Honestly I don't know how the drop away would effect the nodal point....the reading I have done was written far before the drop-away.
Originally Posted by philipdimondo
On the flip side the frequency has a lot to do with the amount of time on the string so as an example I seem to remember .018 seconds....and the frequency being like in the area of 64 hz.... Doing the math would indicate the arrow's frequency is somehow related to the amount of time on the string...???? This was quite a few years ago that I did this reading so my memory might be somewhat skewed.....This would indicate that a drop away probably has no effect on the nodes because they are more related to the string time...
June 29th, 2005, 03:53 PM
go with the 500's. There is no sense in pushing the spine to the limit and I personally see no downside to even ultra-stiff arrows
June 29th, 2005, 05:34 PM
James Park, of Australia, is a firm believer on arrow frequency as a mean to tune.
Joe Tapley, of the Bow Mechanics and Arrow Flight page, says nodes don't matter.
So, the fact is 'shoot what is better for you!'
June 30th, 2005, 03:07 AM
If two arrows are identical apart from length of shaft then the shorter arrow will have a higher FOC, less overall weight and a higher launch speed.
The short arrow will group better in both wind and no wind conditions.
June 30th, 2005, 06:37 AM
Interesting, Joe T. Should we conclude then that all archers should strive for shorter arrows to get tighter groups? Long draw length archers would then be returning to long overdraw devices? Certainly true for bullets.
June 30th, 2005, 07:01 AM
You have mechanical restraints on the length of the arrow from the bow.
For recurve the button/rest need to be above the grip (torque issues) so minimum length determined by draw length + brace height + enough arrow over the button to get the pile insert off it.
You'll have similar restraints for compund - but don't know nuffin about them
seems I can't even spell the word.
Last edited by Joe T; June 30th, 2005 at 07:04 AM.
June 30th, 2005, 08:54 AM
Assuming both arrows are spined perfectly ,and fletched identicaly . I would say the longer arrow would be more accurate ,with crosswind not being a factor , to a point . The resoning behind that conclusion is that the stearing in the rear of the arrow is futher back , in relation , as compared to the shorter arrow , therefor have geater leaverage of the forces on the arrow . That is the reason I think most will find useing 4 - 3" feathers will stear an arrow better than 3 - 4" feathers . Allthough they have the same area of fletching , you in effect move the stearing of the arrow rearward useing 4 - 3" feathers as opposed to useing 3 -4" feathers . There are other factors allso Im sure 4 feathers disrupt the airfloww diferantly than 3 feathers .
July 1st, 2005, 03:08 AM
Problem is that although the length of the lever changes so does the weight of the thing your pushing and so does how hard you're pushing it. Also the forces pushing the arrow off-line are also different. You have to look at the grouping performance in terms of the arrow as an overall "package" with the net combined effect of all the different inter-related factors. Looking at one factor by itself doesn't tell you anything.
the stearing in the rear of the arrow is futher back , in relation , as compared to the shorter arrow , therefor have geater leaverage
July 1st, 2005, 12:55 PM
arrow length discussion
Thr granularity of spine by definition is not vernier in nature. Viewing any of the arrow algorythms and deviating say pound for pound you will notice a given spine works well for say a 3-5 pound change.Same is true for the other variables including arrow length. If we accept that any error should be towards stiffer then any given arrow that is shorter should have an advantage over the same arrow longer. Short DL archers have complained they were penalized in speed over long DL archers who could generate more energy in the bow limbs and into the arrow. However, short DL archers arrows are on the string a shorter period of time and should be able to produce tighter groups in a shorter period of time than the long DL archer. This assumes that form flaws in short DL/short arrow archer are not as critical as the same form flaw in longer DL archers. The one factor here that probably needs consideration is time. Slow arrows have the advantage of correcting more of the error that a faster arrow. However, any comparison would require holding thase things constant that you can and and establishing a control, say 28", and measure the groupings of long and short arrows against the control. Would be interesting to know if Easton and others have ever done such a test.
July 1st, 2005, 01:23 PM
hats off to tap. man you know you stuff
July 1st, 2005, 02:27 PM
I just completed an experiment which show something I didn't suspect. I had some Beman Matrix 400's. They are a discontinued arrow shaft similar to ACC's. I had the shafts too long to begin with and then shortened my draw. They weighted 400 grains ready to fly.
I took a half dozen and cut them down by two inches which reduced the weight to 380 grains. Now you would suspect that the shorter arrow would go faster and therefore have less drop, but that is not what exactly happened.
The shorter arrow started out a little faster @ 269 fps, but it was only two fps faster than the longer arrow. The arrow shot to the same sight setting as before until I reached about 40 yards and then by the time I was shooting at 50 yards, the longer heavier arrow was shooting about one index mark higher on the my CJ scale.
All other things were the same same chronograph bow, day, etc. There were six of each arrow sets and all arrows were within half of a grain of the weight in their set.
The only thing, I can determine from this test is the longer arrow flew flatter than the shorter one because of KE transfer. The bow was able to transfer more energy to the longer arrow and therefore it's momentum was carrying it further than the shorter one.
This stuff is not linear and engineers have written many volumes on air flow and drag. Most of the physicist such as Newton and Galileo were trying to develop scientific principles for ballistic tables. An arrow is nothing more than a long projectile.
Let's for a moment assume that we have two arrows each are the same weight, FOC, fletching, point style and shape, etc. The only difference is the dia. They are both shot through the same bow and achieve the same speed initial. We will take the length and divide it by the dia of each shaft and call it the aspect ratio. Now, obviously the large one will punch larger holes in paper, but the smaller on is going to have less trajectory loss and wind drift.
Why, will this happen? It is because of surface drag which will lead to velocity decay. The formula for determining the surfaces area of a cylinder is PI * R(radius) squared * length and the cross sectional area would be length * dia.
Let's take an ACE with a dia of .22 and a Fatboy with the dia of .38 or there about both are 29" lg.
Total cylindrical surface for the ACE equals 1.102 sq. inches
Total cylindrical surface for the FATBOYS equals 3.288 sq. inches
Total cross section area for ACE equals 6.38 sq. inches on cylinder cross section
Total cross section area for FATBOY equals 11.02 sq. inches on cylinder cross section
So basically since the cylindrical surface is almost 3 time different between the two shafts, the FATBOY will go into velocity decay much faster than the thinner shaft because of surface drag. If both arrows were shot at a 90 meter FITA target the ACE would arrive quicker. The ACE almost has half the cross section area and will wind drift less because of this, plus it total time in flight is less.
Now, all that being said, which one is "best"? Certainly, for FITA keep the FATBOY's home, but they are a good shaft for 3D where they can cut more lines.
Every bow has a "sweet spot" were it can transfer the most KE into the arrow and if the dia is reduced to its min. it will fly further and straighter than any other combination. But, the higher the aspect ratio is the arrow will fly further if it is properly spined and receives max. energy transfer.
Actually, while Newton and Galileo made significant physics laws and discoveries, they were totally unsuccessful at developing "good" ballistic tables because they did not determine the effects of air drag. They both ASS-U-MEd that air drag was an insignificant factor.
Last edited by Deezlin; July 1st, 2005 at 02:44 PM.
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July 1st, 2005, 03:08 PM
accuracy vs arrow length
Wll stated. I deduce from this that we can accurately predict the decay from either arrow, long and short, as a constant. So the only delta is how the sight is adjusted. Of course assumes both spines are stable for the bow. If true then both long and short DL archers can shoot just as accurate as long as they have a repeatable process wherin the archer can account for drag and the effect of gravity. Kind of what we all do without understanding why. Discussions of this sort can go a long way towards us understanding and characterizing why some shots(arrows) fall outside of a normal gaussian distribution. The ability to predict before you cut an arrow is a valuable tool. Seems we have come full circle to the action of when id doubt make arrows stiffer albeit by lighter points heavier vanes or shorter arrows.
July 1st, 2005, 04:35 PM
Your results aren't that unexpected. The shorter arrow has a higher launch speed but a 'better grouping' arrow will incur more 'slow the arrow down' drag. The shorter arrow could hit higher or lower than the longer arrow depending as said before on the overall package. Which way it goes is very much depends on the arrow diameter.
Worth remembering that just because an arrow hits higher it doesn't necessarily mean that the arrow is 'better' as far as groups go.
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