The stiffness of a pole increases exponentially

[kcvault]

This is the same question I am trying to get answered but every time I just get an explanation of how essx is the superior pole. I am not trying to be sold on what pole is better. I just want to know how pole companies, all pole companies determine the weight rating. There must be some sort of standard that every company must use or a 180 spirit could possible be a 160 essx. So what is the system that makes a 180 a 180 and not a 160 even after all these post I have no idea how companies determine the weight rating on a pole.

---Kasey

[tsorenson]

After reading previous threads on this same topic... the best I can tell is that each company's charts deciding which flexes equal which weight ratings are proprietary, and they don't want to release them. I agree that it would be nice if there was a universal standard, but let's face it, most industries are not universal (PC vs. Mac, etc.) I like Becca's (and others') idea to flex your own poles using your own system to determine their relative stiffness rather than trusting flex numbers of differing brands. For beginners, I recommend "feeling" the difference between poles by doing some wall plants before just grabbing a new pole and trying to jump on it based on weight OR flex. There always seem to be poles that don't fit where they are supposed to...

The real problem arises when you BUY a pole that ends up being very different than what you expected...I bought a 190# pole that crushes people (including myself) compared to other 190's...I have had to realize that it is actually NOT a 190, and last year I loaned it to a 220# decathlete who barely bent it...I borrowed a pole of the same make/model, also rated 190#, that I easily jumped on first try in a meet...it was significantly softer! The flex number was only .2 difference between the two poles.

I like Bruce's idea of going up by kilos to reduce the "rounding up" effect that can cause my "185" (from the same manufacturer) to feel at least 10# softer than my "190." I do also appreciate him taking the time to explain some of the details of the pole-making process and how his poles are flexed. It would also be nice if pole vendors would include the flex # when customers order poles, allowing those of us who understand flex #'s to decide if we should actually order a different pole altogether and not get stuck with $500+ of fiberglass we don't need or can't use. I understand that this may not be practical due to cost/inventory issues.

Since many vaulters have different "styles" even within a particular "model," and vaulters' physical parameters change as we get older, I suppose we should be glad that there are many types of poles to choose from, with various sail designs and return speed! Maybe after eating a lot this holiday season, my "190++" pole will feel just right...

Happy Holidays,

Tom

[rainbowgirl28]

It would also be nice if pole vendors would include the flex # when customers order poles, allowing those of us who understand flex #'s to decide if we should actually order a different pole altogether and not get stuck with $500+ of fiberglass we don't need or can't use. I understand that this may not be practical due to cost/inventory issues.

Anyone can order poles by flex, you just have to call the manufacturer.

[gtc]

I can get you any flex Altius Pole you want (fiberlglass or carbon) in inches or centimeters. And tell you exactly how it compares to any other brand at any length, weight/stiffness.

www.justvault.org

just email or call

[fdavaulter]

It would also be nice if pole vendors would include the flex # when customers order poles, allowing those of us who understand flex #'s to decide if we should actually order a different pole altogether and not get stuck with $500+ of fiberglass we don't need or can't use. I understand that this may not be practical due to cost/inventory issues.

Anyone can order poles by flex, you just have to call the manufacturer.

Email us and we will get you any size Essx, s-glass or carbon pole by any flex or length that you need with in a week... You can buy it or rent it for the season...
We have the best pricing.. Call us for your next order
612-987-6147
Fuzion Athletics
rentalsales@fuzionathletics.com

[tsorenson]

Ask and you shall receive...thanks guys! If only I had the $$ for a pole right now...
I jumped on an Altius training pole in practice when I was in college (it was blue, 14'ish, rated 180-200 lbs.) and loved it for short runs. Do they still make these training poles, or have they discontinued them due to the new HS weight rule requiring poles to have a specific weight rating? I emailed Altius (the manufacturer, not Alan Launder) a while back asking this question but never heard back.

Cheers,
Tom

[achtungpv]

Anyone can order poles by flex, you just have to call the manufacturer.

Bingo. Saw a kid a few years ago that'd bought a couple of brand new poles by the weight instead of flex numbers. The weights were 5 lbs apart but the flex numbers were .1 apart. He had literally just spent $800+ on what amounted to one pole.

[Bruce Caldwell]

Divalent
That was interesting (really!) but I think you misunderstood my question. It was really a lot simpler (I think). Let me try to reframe it based on your example. Forget the cut downs, or wraps or anything else. You have a pole that you label a 15'-135, because after you made it, you tested the flex, and found that's what it was. My question is, given the flex you measure, why do *you* call it a 135 lb pole, and not a 130, or 140 or 150?

What I'm trying to get at is the basis for the requirement in HS that a vaulter vault on a pole rated at or above their weight. Why, in your opinion, is that 15-135 pole unsafe for anyone over 135? (I say "in your opinion" because you label it, and with a 135 label, a 140lb athlete would be DQ'd if they used it in a HS meet, but if you labeled it 145, that *same* pole would be legal. So whatever *you* (and only you) say about the pole determines whether it is legal for a particular athlete).

I presume at this point that you have a table of pole lengths and flex numbers that allows you to assign a weight rating for whatever you make based on those measurements. But how did you decide that (made up example ---> ) a 15' pole with a 17.3 flex is a 135 (or whatever) as opposed to some other maximum weight? IOW, what's the rationale behind the table you use?

KCVAULT This is the same question I am trying to get answered but every time I just get an explanation of how essx is the superior pole. I am not trying to be sold on what pole is better. I just want to know how pole companies, all pole companies determine the weight rating. There must be some sort of standard that every company must use or a 180 spirit could possible be a 160 essx. So what is the system that makes a 180 a 180 and not a 160 even after all these post I have no idea how companies determine the weight rating on a pole.

The answer is wall thickness and structural design, which is determined before the pole is built.
a 15-135 wall or hoop will not hold any more load than 135Lbs based on experience over the past 50 years of making fiberglass poles!
One time Herb Jenks the father of the flex machine thought because the flex number was stiff enough one could lower the handgrip and call it a bigger size pole this is absolutely not true and he stopped offering poles with a variable weight rating because the poles would break using his scale he set up. He then realized that the hoop strength of a pole is only for that rating. holding a 15-135 14' may feel and flex as a 14-145 butt the wall or hoop would not support 145 lb. loads. And when he invented the CATAPOLE and PACER he was trying to increase the hoop in both poles so this variable weight rating would work! After years of experiencing breakage for those who weighed more than the pole they aborted the idea.
Over the years the requirements of hoop and stiffness have given us the ratings we use and the flex number is only the end test to see that we hit the right stiffness. But the flex only measures the stiffness not the hoop other test are used to determine proper hoop strength!
I hope this answers your questions!
Bruce Caldwell

[KirkB]

The answer is wall thickness and structural design, which is determined before the pole is built.

... Over the years the requirements of hoop and stiffness have given us the ratings we use and the flex number is only the end test to see that we hit the right stiffness. But the flex only measures the stiffness not the hoop other test are used to determine proper hoop strength!

And so that's why the mfrs recommend that the pole be gripped within a certain range near the top of the pole.

This clears it up for me! Thanks for that explanation!

Kirk

[Bruce Caldwell]

When building the best pole one must consider the distance of the hand grip to the center of sail piece.
anything smaller will be hard to roll over needed for good vaulting!
Lowering your hand hold below the allowed 18" from the top of the pole will make the vaulting pole bend and return far too different to match and get timed with your double pendulum.
1. Pole does not bend over.
2. Pole returns with forward forces and with very little upward lift .
3. Pole is stiffer and requires more weight or energy to bend it deferring energy from the vault itself.
Same as holding at the very top of the pole within the top 3", pole may bend, roll over, but be too soft in the return of upward lift!
the 12" area is the area you can adjust the feel of the pole and the return at about 1 lb per inch. Optimum area is based on the vaulter and adjustments thereafter will affect the pole action! intricately as .9 lb per inch up softens the pole and for each 1 inch down is .9 lb. per inch making the pole stiffer only in relationship to the starting point of the grip. Other factors are affected too if you wish to get finite about it the pendulum is affected based on the length of each pendulum
1. the pendulum the vaulter!
2. the other pendulum the pole!
Bruce Caldwell

[Divalent]

The answer is wall thickness and structural design, which is determined before the pole is built.
a 15-135 wall or hoop will not hold any more load than 135Lbs based on experience over the past 50 years of making fiberglass poles!...

Yes, I think that answers the question. Essentially, it really comes down to avoiding structural failure. Which means, also, that to the extent different pole models (and poles from different manufacturers) have different wall thickness, structural design, materials, etc, then:
1. weight rating is not a reliable means of assessing the "flex" characteristics of a pole, relative to a pole with a different structure or design. e.g., a 12-155 from one mfg might behave like a 145 or 165 pole from another. (Only comparisons of the same mfg and model, made the same year, would be reliable.)
2. The direct connection to safefy is with respect to breakage, not the characteristics of the vault a person using it might produce (e.g., a 145 lb vaulter might routinely and severely blow through a 150 pole from one mfg but might not if using a 140 pole from another mfg.)
3. Improvements in the structural characteristics of the material used to make a pole might mean, for example, that a particular pole made this year will have a higher weight rating compared to an identical performing pole made with last years materials.

I presume that some safety margin is built in, since the energy a vaulter can apply to the pole depends on the product of their mass times their velocity squared. (presumably something like the kinetic energy of a vaulter running at world class speed).

[kcvault]

One time Herb Jenks the father of the flex machine thought because the flex number was stiff enough one could lower the handgrip and call it a bigger size pole this is absolutely not true and he stopped offering poles with a variable weight rating because the poles would break using his scale he set up. He then realized that the hoop strength of a pole is only for that rating. holding a 15-135 14' may feel and flex as a 14-145 butt the wall or hoop would not support 145 lb. loads.

I am a little confused because this completly goes aginst my exsperince with modern poles. I have jumped 2ft 8inces off my top hand with a pole 5 pounds under my body weight and 3ft 4 inces off my top hand with one 2 pounds over my body weight. It usually takes a pole 25 or 30 lbs over someones body weight to do that which is about the estimated size of my pole from where I was holding. I have taken at least 200 jumps on a 16ft 190 wieghing 195 but holding 14-10 and never broke it. One of my 5 left pole is a 16ft 180 which anyone who has seen me jump will tell you I have jumped on at least 2000 times, and over 35 times in a day. Yet I weighed anywhere between 185 and 195 the entire time I have have jumped on this pole over the last six years. The pole still hasnt broke because I have never held higher the 14'8 yet I have jumped over 16ft on it. Maby it's because I have only done this with carbon fx, pacer fx, spirit, and pacer carbon poles. If it is not true of other poles then I guess the brands I just mentioned really are woth more because being able to do this with them will save people a whole lot of money. However I am pretty sure it is true of pretty much all modern poles.

--Kasey