Historical Jump - New PV Pole Design used in 1st Competition

[bentleyw]

Alex Bentley jumped for the first time in competition on a patent pending, newly developed pole vault pole design at the Rice Twighlight Meet in Houston TX on Saturday, April 24, 2010. He completed three jumps on the inovative pole and cleared the bar on all three attempts.

http://www.youtube.com/watch?v=anQlU5QWpWY

The newly invented pole design is the creation of William Bentley of Houston, TX and is called the "BENTLEYEliteHP".

The "BENTLEYEliteHP" design has two separate benefits derived from the single inovation: 1) It enables a vaulter to achieve a higher "angle of attack" at the moment of "planting" the pole into the box; and 2) provides an improved ergonomic hold by the vaulter's right hand enabling a stronger grip (also enabling easier pole alignment with the body while in the inverted position)throughout the vault.

[KirkB]

1) It enables a vaulter to achieve a higher "angle of attack" at the moment of "planting" the pole into the box ...

I can understand your 2nd benefit ... due the the angle offset on the "grip" part of the pole.

Can you explain the 1st benefit? How does the angle offset increase the angle of attack?

And I'm wondering if there's a 3rd "perceived" benefit. I assume that the "prebend" under the grip is going to be perfectly aligned with the intended direction of bend. Could this prebend possibly also give the vaulter the confidence that the pole WILL BEND without any push, press, or blocking with the bottom arm? Due to the offset, it should be obvious that there's leverage there that will bend the pole. This leverage isn't obvious in a straight pole.

I'm being careful in how I word this, as I personally do NOT believe that there should ever be any concern of the pole bending by the forwards/downwards pressure from the top hand ONLY. The pole WILL bend! However, there are lots of vaulters that don't share my belief ... vaulters that have never experienced the pole bending without SOME influence of the bottom hand. That's why I call this a "perceived" benefit.

So for these people ... who probably even outnumber the pure Petrovists like myself ... do you see that as a "perceived" benefit?

Lastly, what's the rest of the pole like ... compared to other popular brands?

BTW ... congratulations on Alex's Petrov technique. Very nice! The technique is more important than the pole ... always!

Kirk

[bentleyw]

First of all let me explain a few things you probably already know. The bend at the top of this pole has absolutely nothing to do with getting the pole to bend in any direction or otherwise. Poles today have a "pre-bend"(yes, poles are not actually straight) in them that takes care of that. And, if the vaulter does things right the pole will bend as a result of the energy transitioning into the pole from his run and plant and not from him trying to make it bend. The direction of the force vector created by his mass moving in a direction, along with the "pre-bend" (assuming the pole is held correctly), will dictate the direction of the bend. But, technique here is not the issue. There are a few more "subtle" benefits to this pole than mentioned, but at this time they are not particularly relevant. So, in summary, there is no "perceived" benefit of helping to bend the pole unless it is in the mind of a less experienced vaulter.

1) This pole is NOT designed to be a "crutch" for poor technique.

2) The vaulter changes nothing to adapt to using this pole. Actually, one vaulter said that if he were blindfolded he would not be aware that he wasn't running and planting on a traditionally designed pole.

3) As mentioned, the first benefit is that the designed angle between the vaulter's grip allows him to achieve a slightly higher angle at the point of impact than he would otherwise be able to achieve with an identical jump. I have been told, "Why not just teach the vaulter to have better technique instead?" I couldn't agree more (refer to item #1) except that, assuming the vaulter performed a jump to the very best of his ability, this design could allow him to get on the next larger pole. With the identical jump, he would clear a higher bar.

4) The 2nd benefit was a surprise. It was noted when the first prototype was made. Initial testing proved the ergonomics of the design to be separate and equally significant benefit.

5) This is a design modification to a pole that DOES NOT measurably affect the way a pole is engineered -- only the way it performs.

Let me interject an important point here about pole vault pole progress. Some vaulting purists might advocate that we still use a wooden staff with a pointed steel tip on the end! Pole vault poles today are not made like pole vault poles 50 years ago and I would be surprised if in 50 years they will be made tha same as the ones today. Bubka would not have cleared over 20 ft on a bamboo or aluminum pole. I hope I've made a point here.

Thanks for the kind comment on Alex's technique. Actually, he was very disappointed in this example of his jump. He was low and had an early plant. But, otherwise it does follow Petrov. And, I agree, technique is more important than the pole.

[master]

What is the angle of the 'fabricated bend' near the top of the pole? Have you determined if there is an optimum angle? It seems it would provide the most benefit if the vaulter would grip is lower hand just below the 'fabricated bend'. Is that your thinking also? In the single jump video, the vaulter's right hand was just above the bend which would be the point where I would think there would be the least #1 advantage.

It is a very interesting idea; one that will probably cause more than a casual mental review by serious vaulters and coaches.

[vaultmd]

Dr. Jim Vernon at USC was doing that 35 years ago. His bend point was different, but I suspect the benefits were similar in that it allowed him to get off the ground better than without it.

Nevertheless, it is great to see the Texas Medical Center in the background. I was faculty there in the early 90's.

[bentleyw]

Thanks for the great questions. There is an optimum angle. Like most things, more is usually not better. Unfortunately, some information is proprietary.

You are most correct on several points. The closer the right hand is to the "designed deviation" [fabricated bend] the less the derived benefit. In this case, Alex needed to grip down on the pole in order to be able to vault on it. This was a 15'6" 185 pole and that is where he holds on a standard pole. Even though the pole did move better for him than a standard one, the ergonomic design was the primary benefit in this example (He mentioned it was significant). The ergonomic benefit is most advantageous in the hands of an experienced vaulter -- like a titanium shaft is to Tiger Woods.

I don't determine that the left hand has a benefit by being closer to the "deviation". Two issues arise: 1) the vaulter's left shoulder would be high and not "square" at the plant. 2) Consideration must be given to not interfering with the engineering of the pole design. Where the modification is placed has no measurable change to the pole's flex. Believe it or not, factors in pole construction can have a slight affect on the flex over time -- maybe 0.1. On the prototype, it was almost exactly the original flex +or - 0.05.

I like to view this innovation in two ways: First: It is a simple concept (It is basic physics. It is NOT a substitute for good technique). Second: For the thinkers, there is a lot to ponder.

I do realize that some vaulters will get spooked by it at first.

Again, thanks for your constructive comments.

Wm

[bentleyw]

Over the years, I discovered that the concept had been experimented with by individuals as well as manufacturers. Those concepts proved problematic (as did my first idea) for several reasons. Great medical center. Thanks.

[KirkB]

Dr. Jim Vernon at USC was doing that 35 years ago. His bend point was different, but I suspect the benefits were similar in that it allowed him to get off the ground better than without it ...

Here's a link to another thread that mentions Vernon and his banana poles ... the ones with the huge prebend!

http://www.polevaultpower.com/forum/viewtopic.php?f=8&t=4657&p=111322&hilit=pre+bend+prebend+banana+poles#p111322

Kirk

[bentleyw]

Interesting. Thanks.