EFOC effect on arrow shaft lifespan

[CRS]

I was pondering the other day while shooting my carbons with 300gr tips up front.

Does EFOC with the heavy tips reduce the lifespan of arrow shafts?

With the heavier weight up front, that would cause more flexing in the arrow shaft on each shot, causing the arrow material to weaken and lose spine. This could happen with any of the materials.

I have had arrows that just quit shooting as good as they used to.  I believe it was due to the fatigue in the material.

My guess is this would cause more problems with wood, aluminum then carbon since it is kind of a wonder material.  But at some point it would have to give out.  

What does everyone think?

[Manitoba Stickflinger]

Never thought about it. If nothing else it gives me another great excuse when I miss!

[Bjorn]

My arrows quit shooting as good as they used to all the time, and I don't even have an EFOC!    

[Ragnarok Forge]

Actually the EFOC moves the bending point of the shaft forward and causes there to be less flexing of the shaft at the shot and less on impact.  EFOC arrow recover quicker than standard or HFOC arrows do on the shot.  Based on your post EFOC should increase the life of you arrow based on your original assumption.  I have a dozen carbons that are getting close to 3 years old and have thousands of shots on each arrow, they shoot like they were made yesterday.

[arrowlauncherdj]

I would say no, because the bending force on an arrow that is meant to shoot out of a 70 lb compound bow with normal tip weight would be equivalent to the EFOC set up on say a 50lb recurve when it is tuned for that particular bow.

In other words, the arrow still has to bend around the riser and the force required to bend the arrow around the riser is no greater coming from the weaker recurve with really heavy point weight vs. the heavy weight compound with light tips.

Hope that makes sense.  Seemed to work in my mind anyway

[danderson]

Now, I don't know much about EFOC, but the arrow still has to have the same dynamic spine to flex around the riser, so technically, it isn't bending more than a light headed shaft

[CRS]

Interesting thoughts.  Remember this is just pondering.

I can't see the less flexing upon release, but I can see the quicker recovery and less flex at impact due to the weight forward balance.

I was thinking that the heavier weight point would cause more arrow flex.  A heavier point would start to move later.

 A properly tuned  arrow is going to have the same amount of flex.  Therefore a longer arrow would be stressed less than a shorter arrow?  Kind of like longer limbs are stressed less than shorter limbs. Which is another factor.

The simple fact that the arrow has to bend around a riser vs center shot bow would cause more stress on the arrow.  

Carbon is a superior material for arrow shafts.  Simply because it can withstand the repeated stress better than aluminum or wood.  I just did not like it when it first came out because it was physically too light  BUt it does not have the romanticism of wood for sure.

[calgarychef]

I can't accept the less bending at the moment of the shot part of the argument.  

The heavier head resists foreward movement that's a fact and can't be argued.  After release the shaft has to bend a heck of a lot more as it absorbes the forces imparted by the string.  If it's a lighter head it's the opposite, the shaft bends less because the light head doesn't resist as much.

I've always thought that at some point the heavy heads must be dangerous because of the possiblity of the shaft breaking.  I wouldn't use high FOC on a cheap/brittle arrow.

[Whip]

calgary, you would be correct if you assumed just adding more weight up front on the same shaft.  Adding weight up front will make the shaft act weaker, thus bending more.  

But actually, adding weight means that you need to move to a stiffer shaft in order to maintain tuning of the arrow.  Pick the correct shaft and you would end up with an arrow that will bend more or less the same amount as an arrow with a lighter head.  

I can't see where it would make any difference in the life of the material.

[old_goat2]

My arrows always find something way hard and break long before structural fatigue can set in. Either that are they run away from home.

[Bill Carlsen]

You are shooting a stiffer shaft to begin with so the FOC is just an "adjustment" to get the dynamic spine right and the arrow weight up at the same time. I have arrows ten years old that are as good as new.

[CRS]

The effect I am talking about I have noticed mostly with wood/aluminums.  

I too have carbons that I been shooting routinely for 5-6 years.

[trick00]

I would think you could break just about any arrow if you just kept adding weight up front and not stiffining up the spine.

[lpcjon2]

Now I want to know with heavy weight on the end of the shaft upon impact wouldn't that cause some form of structural weakness.having the energy of the impact being absorbed just behind the head, being a 300gr head shot into bone would carry more( I guess deflected would be the word ) deflected energy toward the rear of the arrow than a head of a lesser weight. and then causing more stress on the arrow.

[awbowman]

Too deep of a thought for me, I just like shooting.

[Andy Cooper]

If someone will send me some 500 gr broadheads, I'll do some testing!
     

[CRS]

Sorry, for the deep thought.

I think the heavy point takes most of the beating upon impact as there is not as much weight behind the point.

[JimB]

I guess this is all speculation but if an arrow penetrates deeper than another arrow doesn't that mean it isn't stopping as suddenly,so less jolt to that arrow?I personally don't think you will see a difference in any of them.

[Doc Nock]

When Gold Tip first came out, they posted a high speed video on their website. In fact, it was done up and sold as a video and a chap sent it to me to review. That was in the dial-up days and watching on line was a pure pain!    

Wood and aluminum came off the bow in paradox, yes.  Then both materials continued to oscillate down range through the whole flight, robbing stored energy, (that was GT's narrator's take) and it made face validity sense to me, knowing what little I remember from college physics. (isn't that what gradma gave us when we couldn't go, a physic? Maybe it was spelled differently?)    

By comparison, the carbon arrow, went thru paradox ONCE and then never oscillated again throughout the flight...blowing thru the target.  NOT because of the more slender diameter (which was then a favorite speculation), but due to the fact that it retained more of the energy imparted by the bow on release, according to the narrator.

The analogy, as I recall, went further: They made the reference to a dragster going down the track as fast as it could in a very straight line...but if you were to swerve back and forth, you'd loose momentum/speed!

GT was ONE of the first that was not 'pultrued' (sp?) and therefore was not the soda straw diameter that shattered. GT's were then about .001 less in dia than a 2018. Thin, but not extremely so...

The aluminum's behavior on impact, I remember well, as I was shooting all aluminum for hunting. Aluminum arrows, on impact looked in the high speed video to almost "fold in half"... and then straighten out!      

THAT...that freaked me out! I have been shooting carbons since then of varied types.

So the "flexing" issue on carbons is mimimal compared to other arrow shaft materials.  The higher FOC is purported to be, as a string tied to a rock where the string (shaft) just follows along once in motion.

Fun brain exercises... at my age, it pays cause they say it wards off alzheimers!          :rolleyes:

[Jeff Strubberg]

I would bet that the increase in oscillation of a NON EFOC shaft when it impacts the target would cause more wear than the initial  increased bend of an EFOC shaft would.

In other words, I would think an EFOC shaft would last LONGER.

Of course, we are both assuming that the oscillation of a carbon shaft is enough to cause fatigue over time in the first place.