The Flex # Issue Explained

[rainbowgirl28]

I am sure a lot of you are confused about the debate going on regarding flex numbers. Much as I would like to think the whole pole vault world revolves around my message board, sadly, it does not. This is a complicated issue and much of it is not being discussed on here. Let me try and explain this so you all can understand better.

We all know that you cannot compare flex numbers between brands, even if they are the same length. The standard reason given for this is that the various manufacturers flex their poles in slightly different ways. I believe that all manufacturers hang a 50 pound weight in the middle of their pole, so the main difference would be the points where they hang the pole from.

So most of you knew all that already, so what is the issue now?

Jan Johnson, the National Director of PV safety, has been involved with the ASTM on pole vault related issues. You can read more about the ASTM on their website at http://www.astm.org/ The ASTM are the ones who decided what the minimum size for pole vault pits should be. Note that they are NOT policy makers. The NFHS took this standard and made the unfortunate decision of giving schools less than a year to implement it.

Jan, and others, had the idea that the way manufacturers flex poles should be standardized so that we can compare flex numbers between brands more accurately. Eventually this would help to bring weight ratings in line, and serve to make it easier for schools with a jumble of poles of different brands to know how they compare.

Right now a pole of a given length that is rated at 150 pounds, could be of a variety of stiffnesses, depending on who made it and how long ago it was made. Standardizing the flex number process would be a step toward making all poles of a given length that say 150 pounds, fairly similar in stiffness.

There are several issues here. One is the stiffness of the pole versus the performance characteristics. Bruce says that the differences in pole design mean that the stiffness of the pole will not accurately reflect the performance of the pole. At least one other manufacturer feels that the stiffness of the pole will give you a good indication of how easy the pole will be to use. Of course the flex number only represents how easily the pole will bend, it does not predict how well the pole will unbend. So poles could have the same flex number but one might unbend faster… but the safety issue is that they will both carry you in to the pit at a similar speed. In other words you will not have an instance where one pole will stand you up and one will shoot you out the back of the pit.

As I have considered this issue, I realized that I do not have enough experience to know who is right. I thought about who would know best the difference in flex number versus performance characteristics. In my opinion, the most qualified people to discuss this issue would be coaches who use a series of poles made by different companies, and flex their own poles. I know two coaches who meet that criteria, so I talked to them.

The answers I got were inconclusive. One coach felt that there was sometimes a significant difference in performance. The other disagreed and had no problem making a series of poles for his athletes using the flex numbers he had obtained.

So I am undecided on that one, how does the ASTM decide such things? This process involves a number of people with different areas of expertise who discuss these issues. The ASTM met last week Thursday to discuss many things, including this. Many people were invited to be part of the process, including Bruce. Many representatives from many companies attended. This meeting was just the start of a long process.

So who will end up deciding these issues? Bruce is right in saying it is unfair for one company to get to make these decisions for the whole industry. However, that is certainly not the intention of the ASTM. I just talked to someone who was at the meeting, and he said the plan is to send a letter to all of the manufacturers asking them to have a representative on the task force that examines this. That’s right, they want ALL of the manufacturers to come to an agreement on this.

This is not about one company trying to control the industry. It is about the industry coming together to make the sport safer for everyone.


Some more points…

Bruce brought up the fact that a crossbar can have a flex number. Even the tube your pole came in could be given a flex number! This is not particularly important, guidelines will be in place so that it will have to be a pole designed for vaulting.

None of this will affect elite vaulters. This is all aimed at the high school level where generally coaches are less knowledgable, and they are not exactly ordering by flex # (of course there are exceptions to this, I am just making a generalization).

Why hasn’t so and so, or so and so replied to this issue? There are a number of reasons why certain people have not been posting. Some are not allowed to by their boss. Some choose not to for their own reasons. Some risk hurting their political allegiances if they don’t agree with whomever they may represent, even if they only indirectly represent them.

It is unfortunate that not everyone is free to share their opinions. I thought about allowing anonymous posting, but it really does no good. There would be no way of knowing if an opinion came from a 10 foot high school vaulter, or the president of a pole manufacturing company!

I hope this has helped you all to understand the issue a little better.

[~jj~]

Rainbow,
Nice analysis of the problem. Your ability to grasp a problem and look at in in a fair and unbiased manner once again appears to be your strong suit!!!!
The ASTM meeting in Tampa went fine. We had a large number of people in attendance and discussed a variety of topics including standards for helmets, box collars, standard base padding and vaulting poles. I personally came away from the meeting with a good feeling. It may be possible to publish the meeting minutes at sometime in the future, however, I am uncertian regarding this possibility. I will have to check with the rest of the members and the ASTM adminstration to see if this is ok. In addition, since the minutes are not approved until the next meeting (in July at the trials), I do not think it would be possbile until then.
In general, I think it was the collective opinion of those attending that a standard would be good for the pole vault industry. However, the hard part will be arriving at a mutually acceptable system.
Much work will need to be done, the manufactures will have to cooperate with each other, and ultimalty the national governing body's will have to mandate, for it to have a real effect.
~jan johnson~
National Safety Chair
www.pvscb.com
www.skyjumpers.com

[Bruce Caldwell]

BECCA Your explanation was a very good analogy of what is going on
Thanks for putting it in layman terms for everyone.

Bruce Caldwell

[rainbowgirl28]

Here is a press release from September about this topic:

For Immediate Release Press Contact: Barbara Schindler
Release #6780 610/832-9603;bschindl@astm.org


ASTM Targets Further Progress in Pole Vault Standards
and Safety at Upcoming Meeting

All Interested Stakeholders Are Welcome to Participate

W. CONSHOHOCKEN, Pa., 10 September 2003--ASTM International, one of the largest voluntary standards development organizations in the world, through its Committee F08 on Sports Equipment and Facilities will continue targeted efforts to improve safety in the sport of pole-vaulting at the next meeting in November.

After several years of standards development work, a permanent subcommittee was formed earlier this year under ASTM Committee F08 to address the need for voluntary consensus standards in pole-vaulting. The subcommittee, with its designation, F08.67 on Pole Vault, has established specifications pertaining to pole vault landing pits and has several other pole vault-related standards currently in draft form. These standards and other topics will be the focus of the F08.67 meetings on Thursday, Nov. 20, during ASTM committee week meetings in Tampa, Fla. At the same time, another F08 subcommittee, F08.53 on Headgear and Helmets, will discuss pole vault headgear as part of the committee’s agenda.

"F08.67 has brought together numerous stakeholders and experts under the ASTM International umbrella to work on the collective goal of improving safety and minimizing risk in the sport of pole vaulting," noted Eddie Seese, F08.67 subcommittee chairman and president of Personal Record Sports of Vallejo, Calif. “The efforts of the individuals on the subcommittee and others have led to a great deal of progress to date in improving pole vault safety. As we continue our efforts to further safety, we welcome the contributions of all interested parties who wish to participate."

Individuals interested in attending upcoming F08.67 meetings in Tampa, Fla. or for membership or meeting details, contact Jim Olshefsky, director, Committee Services, ASTM International (phone: 610/832-9714; jolshefs@astm.org).

Established in 1898, ASTM International provides a global forum for the development and publication of voluntary consensus standards for materials, products, systems, and services. ASTM International standards are accepted and used in research and development, product testing, quality systems, and commercial transactions around the globe.

[Russ]

I also attended the ASTM meetings in Tampa last week.

I concur with Jan. You've done a nice job of summarizing the issues. As is the case with most decisions, there are pros and cons associated with arriving at a universal flexing system (i.e., agreeing on what spans to use, testing apparatus, and load when conducting a deflection test). But even if the ASTM were to promulgate an "ASTM Flex" system, presumably that still would not prohibit any manufacturer from continuing to label their poles as they always have done.

Suppose, for example, that the ASTM were to promulgate an "ASTM Flex" system, and suppose further that the IAAF, USATF, NCAA, and NFHS all were to amend their rules to require that all poles after a certain date bear a sticker that shows what the "ASTM Flex" number is. It would be like soft drink bottles that show the volume in both ounces and liters. A pole manufacturer could still affix its own flex number and its own weight rating (presumably the weight-rating would generally be based upon the flex numbers - but given that several manufacturers appear to think that somehow other "performance characteristics" might be included in the weight-rating calculus, they would still be free to label their poles with whatever weight rating they deem appropriate) in addition to the ASTM Flex number.

For example a label could read: "ASTM Flex: 19.5/Gill Flex: 19.7 13-150" (of course this hypothetical assumes that the Gill flex measurement could be slightly different from the hypothetical ASTM flex number).

[Bruce Caldwell]

Ok WHo won the bet as to how long it would take me to post here (GRIN)

The problem is that the almighty flex number has been over rated!!
You have to understand what a flex number is before analyzing it!

A flex number does not determine the weight rating of the pole produced;
the pole maker determines the weight rating and load capabilities based on;

1. The pattern position of the glass and its variable angles,
2. The material used in the pattern,
3. The way it is applied,
4. The diameter of the mandrel used,
5. The flow scheduled for the production of the part,
6. The temperature and time the part is cured,
7. And a few more items that cannot be mentioned here in a public forum.

The above is what makes the pole the weight rating and load capabilities!!!

And then the pole maker will measure the pole for a flex number using their system to make a comparison to the previous poles they have made to maintain a production consistency. Their flex number for their weight rating may be different than others even if it is measured on the same span.
The current flexing system used today by all manufacturers even with its differences between brands are immaterial and not a safety hazard. Other words where is the problem?
It is not a safety issue; it is not a coaching problem as the flex number if used as a guide within a brand works if you understand it? It sounds like it is the same problem/ education!!!!

LIABILITY
If a standard is in place and a flex number is forced on the manufacturer who is going to be responsible for telling a manufacturer what flex to place on their vaulting pole?

It sounds like there is more of a need for continuity, and we have been in discussions with UCS Spirit, and Altius and we are in line with their flex spans.
And we find that there is little difference between the ratings of our poles and theirs. We do have a difference between Gill poles and ours.

So who is using the standard? (Defined as the system that has been around the longest.)
Which company has the standard?
Lets look at where everyone got their standard flex system ok!

I have seen and worked with the Skypole flex chart designed by Herb Jenks from 1972 to 1982 before skypole was sold to GILL.

I had seen and worked with the Catapole Flex chart designed by Herb Jenks when my previous employment bought Catapole in 1994.
I own the original flex machine today and have improved its accuracy.
See link http://f2.pg.photos.yahoo.com/ph/essxsp ... C-002F.jpg

http://f2.pg.photos.yahoo.com/ph/essxsp ... C-001F.jpg

The Spirit pole makers worked with Herb Jenks at AMF Pacer until Gill purchased the Pacer operations. They claim to have moved the same system over to their new operations at UCS spirit.

I am told that Gill when they received the Pacer operations kept the same flex system designed by Herb Jenks.

[rainbowgirl28]

I'll go with flex number over weight rating any day.

I have a series of poles at my high school. Lots of different brands. My school cannot afford to go buy all new poles of the same brand, so I just do my best to fill in the gaps where I can.

We have a 14'150 and 160 Spirit. Then we have a 14'170 Altius. The 160 Spirit is pretty soft, everyone who has jumped on it doesn't think it feels a full 10 pounds stiffer than the 150. The 170 Altius is stiff as a log. Gee I wonder why... I go to pole vault camp and get an Altius flex chart. The 170 is now rated a 180! Good thing I did not stick my kid who was blowing through the 160 on it.

When I am out of college and set up coaching somewhere, I plan on flexing my own poles. It may not be 100% precise, but it gives me a place to start.

[Barto]

Got to agree with 'becca. I've flexed alot of poles over the years. I've never seen one with a softer flex be bigger than one with a stiffer flex - no matter what the brand.

Flex numbers are by far the most accurate way for coaches and vaulters to measure the relative stiffness of their poles!

Barto

[Bruce Caldwell]

Does your Altius have a flex number and do the spirits. How do they compare? That is the question?
The Altius may have an Imperial number that can be converted very easily by multiplying the imperial number by 2.54 to arrive at the Metric flex number to compare.

Yes, using the flex number will help you to get a feel of the differences between the poles within the brand. It will give you a relative stiffness measure between poles and brnads, this is correct. But it is not an exact measure from brand to brand. The comparisons may vary only a few mm between brands but it is not a way to set up a standard unless they want to allow a give or take by .01 to .08. Tolerances such as that would not be a standard.

I am not saying you can’t use the flex number to get a comparison because we ask what the flex number is often when changing people over to our pole. It is a guide and not an exact number.
Having a standard would mean having a method that fairly measured all brands for comparison

I read on here that people want to use the flex as a guide that is fine, but what the ASTM is asking is to use it as a finite number a fixed to a weight rating that is a totally differrent thing

[rainbowgirl28]

Does your Altius have a flex number and do the spirits. How do they compare? That is the question?
The Altius may have an Imperial number that can be converted very easily by multiplying the imperial number by 2.54 to arrive at the Metric flex number to compare.

The 150 is a 20.9, the 160 18.8, the Altius is 6.2 inches which would be... 15.75cm. but I would rather flex them myself so that I get a better idea of how much stiffer they are relatively speaking.

The main thing I want to know as a coach, is whether or not the next pole is too big of a jump and will reject my kid if they try it. I can imagine it must be very frustrating for coaches who don't understand flex numbers, to have a pole that says 160 that throws their kid almost off the back of the pit, and a pole that says 170 that spits the same kid on the runway.

[Bruce Caldwell]

The 150 is a 20.9, the 160 18.8, the Altius is 6.2 inches which would be... 15.75cm. .

SEE if this helps you OK
2.54 cm is one inch
1 inch is a rule of thumb within the grip area roughly a 1lb feel or relative stiffness it is really .9 lbs on some poles.
So converting the metric back to the imperial the first pole is 8.2 the 2nd is 7.4 and the 3rd is 6.2 using this as a rule of thumb the 160 will be 8- 9 lbs stiffer than the 150
The 170 Altius will be 12lbs stiffer than the 160 however the Alitius is a body wrap pole and the spirit is a spin wrap pole so add 2-3 lbs for the Alitius making it 15-16 lbs stiffer.
SO in this case you have a Altius 170 that is a 180 light really a 175 Hard we would call it a 178.2 lbs
A spirit 150 that is a medium flex and a 160 that is a light flex
You may need a transition pole 14- 170 spirit M flex 17.3 to a 17.0 in our line that would be a 169.4 to a 171.6

The main thing I want to know as a coach, is whether or not the next pole is too big of a jump and will reject my kid if they try it. I can imagine it must be very frustrating for coaches who don't understand flex numbers, to have a pole that says 160 that throws their kid almost off the back of the pit, and a pole that says 170 that spits the same kid on the runway.

I agree it is important that is why we call the pole what it is! FORGET THE FLEX NUMBER WE HAVE ALREADY CALCULATED IT FOR THE COACH AND VAULTER
Example:
a 14- pole might read in our line in comparision to the other brands as follows:
S soft flex M medium Flex H Hard Flex
Other brands / ESSX
14-130 S 430/59 129.8
14-130 M 430/60 132.0
14-135 S 430/61 134.2
14-135 M 430/62 136.4
14-135 H 430/63 138.6
14-140 S 430/64 140.8
14-140 H 430/65 143.0
14-145 S 430/66 145.2
14-145 M 430/67 147.4
14-145 H 430/68 149.6
14-150 S 430/69 151.8
14-150 H 430/70 154.0
14-155 M 430/71 156.2
14-155 H 430/72 158.4
14-160 S 430/73 160.6

[Decamouse]

"but what the ASTM is asking is to use it as a finite number a fixed to a weight rating that is a totally differrent thing" - if you had chosen to attend you would realize that what is said above is not correct