DOES ARRROW STRAIGHTNESS REALLY MATTER? WHAT THE ARCHERY INDUSTRY DOESN'T WANT YOU TO KNOW.
For years, I would spend my hard earned money on high end arrows thinking I was getting a better product. Closer tolerances with weight and straightness coupled with some new marketing terms got my dollar bills every single year. In fact, looking back, it pisses me off that the archery world takes advantage of people's ignorance and it pisses me off I didn't do the research not to be ignorant. Ultimately, we are have the purchasing power and we need to hold ourselves accountable.
Now, I know. Now, I understand. I understand the arrow world isn't all that different than the trail camera world we entered back in 2015...simple concepts swallowed up by fancy marketing word's and jargon. I know now that items like arrow straightness matter less then what we are told and the curtain needs to be opened!
HOW IS STRAIGHTNESS MEASURED
First off, much like other product categories in the hunting industry, the lack of testing standards is apparent. ASTM/ATA standards say arrow straightness should be measured along the full length of the shaft minus 2". From my research, some companies will advertise the arrow straightness not throughout the shaft but only the difference between the starting and stopping points (that is obviously amplified for illustration). For example, if the arrow shaft had 1" deflection throughout the shaft but the starting and stopping points of the measurement were within +/- .003" then the straightness tolerance we be labeled as +/- .003". Other companies follow a much more accurate and honest procedure. So if you have a future arrow shaft purchase in mind ask questions!!
I want you to keep something in mind, inside the machining world, straightness tolerances being advertised by arrow companies like +/- .001" are considered to be really high quality work. Now take the CNC mill out of the equation, swap metal for carbon and imagine trying to hold those same tolerances.....you get where I'm going. Unless you know how arrow straightness is being measured, quite frankly, you probably shouldn't trust or buy into it as deep as the industry wants you too.
ILLUSION OF CHOICE
One of the biggest eye openers for me was that, in many cases, carbon arrow shafts regardless of tolerances are EXACTLY the same. Made from the same materials. Made with the same standards. Made with the same construction process. After production runs are completed, arrow shafts are then sorted and grouped together by "straightness" and marketed accordingly. In many cases, the sorting process gives manufactures the opportunity to have multiple sku's of carbon arrow shafts with different straightness tolerances without actually having different arrows!
As the marketing team does their job, prices points are set from the top down, with the straightest arrows being most expensive and marketed to more experienced shooters and the +/- .006" shafts being cheapest and marketed to newbies or price point purchasers.
WHY IT STRAIGHTNESS DOES NOT MATTER IN CARBON SHAFTS
From a physics standpoint or lab setting, straightness does matter to some extent...take long range shooting, bring in a shooting machine, and then repetitively shoot arrows ranging in straightness from +/- .001 to +/- .006. The straighter arrows will absolutely group better. BUT YOU ARE NOT A HOOTER SHOOTER! On top of the idea of human shooting flaws, the difference in grouping between arrows is relatively minimal. So keep yourself, the shooter, in perspective. In reality, there's only a few archers in the world that are skilled and consistent enough to see the benefit from shooting a "near perfect" +/- .001" arrow over a "average" +/- .003" arrow.
When is your arrow shaft actually perfectly straight in flight? I'm referring to straight in flight as straight, un-flexed in all directions, holding it's original shape/form as in rest. NEVER. Once your arrow shaft reacts to the force displaced on it from your bow, your arrow is in a constant state of flexing, bending, and rotationally turning. This phenomenon happens within feet of launch, thus we paper turn at 6ft. Ever step back and continue to shoot through paper to see what happens? It's usually not pretty.
Straightness in carbon shafts is more about selling arrows than increasing accuracy. The actual difference between +/- .001 and +/- .006 shafts is literally hairs.
One of the material property benefits of carbon, is that is resists bending and distorting much better than aluminum. This is what makes carbon arrows so much more durable over aluminum arrows. If you're old enough, think back to the days when everyone shot aluminum shafts and recall the life duration of an aluminum shaft. After a few months of use, out of a dozen aluminum arrows, you likely only had a few with original tolerances. This is why you hear bowhunters say that there are only two types of carbon arrows....straight or broken.
WHAT PART OF YOUR SHAFT NEEDS TO BE STRAIGHT
Understanding and accepting the idea that your arrow is going to flex, bend, and react in flight, the hope is that the arrow shaft will come into equilibrium. Meaning that the arrow shaft has reacted to the driving force from your bow and has now recovered. If you've ever watched any high speed camera footage of an actual arrow in flight, you get this concept. If you haven't I would strongly urge you to do so. The faster your arrow reaches equilibrium the more efficient down range the arrow is. This concept makes spin testing arrows less relevant with carbon arrows unless you are focusing on the shaft from the node of the arrow to the broadhead. Change back to aluminum shafts and you bet your butt spin tests are important.
There are multiple ways to decrease the time for your arrow to reach equilibrium in flight, one being the addition of vanes. The problem with most vane concepts is that they work from drag which inherently increases friction thus reduces speed and overall efficiency down range. Another way to force your arrow to reach equilibrium faster is to simply change the effective length of its dynamic spine. This concept deserves an article all in it owns, but to explain it quickly you shorten the length of arrow that reacts to the driving force from your bow allowing it to recover faster. This also forces your arrow to be straighter, less deformed, less flexed from the broadhead to its node. Fully understanding this concept will show that the straightness of your arrow shaft matters most here.
At the end of the day, archery and bowhunting is largely about confidence. If paying more for an arrow with +/- .001" straightness tolerance gives you more confidence, then by all means spend your dollars there. Regardless of your purchasing decisions, educate yourself on what you are actually getting and become a better consumer.
Author: Chad Sylvester, Exodus Co-Founder