Do longer poles have better "flexibility"?

[treykristianPV]

Going through PVP I found a post that showed Renaud vaulting and I noticed something that made me think of a question that I want more opinions on.

Considering Pole vaulting poles are made of a fiberglass blend, they are not invincible to breaking as some of us may have found out the hard way. What I am curious about though, do longer poles have more tolerance to breaking than shorter poles?

I'll explain a little more. When I watch high school vaulters vault, normally vaulting on 12'-14'-6" poles, vault the poles bend looks with the top half of the bend parallel with the ground and the bottom half of the bend perpendicular to the ground. And it seems if it were to bend anymore we'd be seeing a pole break. But now when I watch, for example; Renaud, who I assume vaults comfortably on 5 meter (16'3") poles, appears to plant the pole and put it into a position that looks as if the bottom half is again perpendicular to the ground, with a huge circular looking bend, and the top part of the pole angled downwards to the ground.

So, considering this, do longer poles have the capability to bend more without breaking compared to shorter poles? Other factors can weigh in, so please give your opinion and why you think so. Please stay on topic of the question mainly though.

[KirkB]

I don't really understand your question.

You say you're observing Lavillenie's (longer) pole bend more than a high schooler's (shorter) pole (more than 90 degrees, roughly), but it's the shorter pole that you say: "it seems if it were to bend anymore we'd be seeing a pole break".

Why do you say this about the shorter pole, and not the longer pole?

And why do you think this is due to the pole length? Or grip length (distance from butt plug to hand), to be more precise.

Kirk

[treykristianPV]

Okay, I'll put it in a different way, so looking at it, I see that they're more pole breaks with the shorter poles than the longer poles. I say this about the shorter pole because it seems to require not nearly as much bend as a longer pole.

This is what I infer from observing high schoolers and Renaud for example. Renaud applies a great amount of flex to his poles, creating enough that if you were to draw an line from the top of the pole straight away from the pole the line would come into contact with the ground. But if someone using a smaller pole put enough bend on the pole to put there shorter pole in that same position the pole tends to break (based off past experiences).

And why do you think this is due to the pole length? Or grip length (distance from butt plug to hand), to be more precise.

I believe that all poles react the same in the way of how far they can bend. In a way that they all create the same radius of arc when being flexed, but since he longer poles have more length they can create more of an arc than shorter poles can resulting in why it appears longer poles can have more flex and still not break.

Trey

[KirkB]

I see what you're saying now. I will debunk your theory ...

I see that there's more pole breaks with the shorter poles than the longer poles. I say this about the shorter pole because it seems to require not nearly as much bend as a longer pole.

This is what I infer from observing high schoolers and Renaud for example.

Your observation that high schoolers break more poles than elites is true. But this isn't because of the length of the pole. It's because of the experience of the vaulter, and the better match between the vaulter's technique and his pole size. Elite vaulters know how to select their poles better, and they can afford to buy a better match between themselves and their pole. They aren't as "foolish" as high schoolers in vaulting on the wrong pole.

Renaud applies a great amount of flex to his poles, creating enough that if you were to draw an line from the top of the pole straight away from the pole the line would come into contact with the ground. But if someone using a smaller pole put enough bend on the pole to put there shorter pole in that same position the pole tends to break ...

I think this is true, and I think the reason is because of the "wrap" of the pole. The strength of the pole (and the extent to which it can bend) is not due to its length, but due to its wrap. Someone else with pole manufacturing knowledge can explain this far better than me. But one example of this might be that Lavillenie's poles have more wrap in the lower half than the upper half. Thus, they bend more like a fishing pole (not in a perfectly circular arc).

I believe that all poles react the same in the way of how far they can bend. In a way that they all create the same radius of arc when being flexed, but since the longer poles have more length they can create more of an arc than shorter poles can resulting in why it appears longer poles can have more flex and still not break.

I see your line of thinking, but if you consider how poles are wrapped, you will now realize that it's a function of how the pole is manufactured, and not how long it is.

Kirk

[treykristianPV]

Thank You Kirk! That actually makes a lot of sense! I can agree with what you've said about the way the poles are wrapped.

They aren't as "foolish" as high schoolers in vaulting on the wrong pole.
Kirk

Should we be concerned with this lack of knowledge high schoolers posses about choosing a right pole? It definitely is concerning to me.

Trey

[GasPasser]

I'd also add that we see more poles break at the HS level because the poles are not as well cared for by the HS athletes as the elite poles are cared for by their vaulters. In addition, HS poles get abused for many years. Most high schools don't buy many poles, so you have some athletes using poles that are not the right pole for their ability, grip, and weight. This can result in over bending, spiking, and contact with standards or other hard surfaces.

Top colleges and elites can afford to replace "suspect" poles. HS poles will keep being used and abused until they break or the school gives up the event.

I'm not saying age alone affects its likeliness to break - rather it's the amount of abuse over the years that takes its toll on the pole. I have some poles that I vault on that are 30 years old - but they have been well cared for.

[Tann2802]

Well, if you shoot some geometry into it, if you have an arc on a 12 foot pole is 90 degrees, and you continue that bend out 4 more feet to 16, the arc that you have created in the bottom 12 feet would continue into the top 4. That being said, there is a few differences in poles that someone like Renaud would jump on and poles that a high schooler jumps on. The sailpiece could be moved up or down depending on the preference of the vaulter. You also have to take into account that Renaud is taking off a good 3 feet behind high school vaulters, so his vertical levels off more in his drive phase. But, back to the point, a longer pole has more room to bend from top to bottom without exceeding any stress limits. A good way to think about it is if you have a piece of raw spaghetti and hold it a cm from the bottom, it'll snap with any pressure, but, if you hold the same piece of spaghetti at the ends and bend it, you will actually see a bend before it breaks because each individual cm has less stress on it if the piece is bent as a whole.

-Montana