Big Bend vs. Smaller Bend

[SKOT]

Sad. track your heights from short approach short stick to long approach long stick. Do you keep the same flyaway figures or better yet do they increase. Or worst yet do they decrease.

I wonder how many 17 foot vaulters we have in this country jumping on 16'5 or longer poles. Yet they can jump let say 16 feet on a 15 foot pole. Shouldn't a light bulb go off.

does this all come straight back to DJ's chart???


http://www.polevaultpower.com/docs/djmidchart.doc

[ADTF Academy]

The equation for kinetic energy generated during the approach is



KE = 1/2 (m) (v)^2

m= mass
v= velocity


Though v is more important than m it is still part of the equation. Additional mass adds to the final result of the equation. Is it wanted, well not if you can't move it.


Plus momentum = (m) (V)

The momentum you take into the plant once you leave the ground is your mass times your velocity. If you carry more mass you have more momentum to over come the inertia the pole has to resist its bending process.


Once again I am not saying mass is overly important or should be the focus. No, but if you can still have top end speed on the runway of 9.5 m/s or faster and your carrying more mass and it doesn't slow you down. You have an advantage as far as generating KE and momentum into the takeoff.

[ADTF Academy]

Skot


All those figures come from general math equation of 16'8 hand hold minus 8" in the box for a 16' effective grip.

If you have a 1 foot flyaway you jump 17 feet

If you have a 2 foot flyway you jump 18 feet

3 foot flyaway you jump 19 feet

4 foot flyaway you jump 20 feet.

and so on and so on

None of this had anythign to do with DJ's chart. It is just simple math.

What pole are you on, what is your hand grip minus the 8" in the box gives you your effective grip. Now how high can you clear. That is your flyaway.

[dj]

good morning

the "fly away" or height above the grip is, in general, created by the velocity/speed created on the swing

that swing velocity is a carry over, created by, the horizontal velocity the vaulter creates at the plant onto the pole and how fast the "bending and un-bending" of the pole takes place... the angles play a major roll as does the length of the "cord" of the pole during pole rotation.. shorter cord faster rotation.. faster swing speed.. potentially higher above grip...

ADTF

i have to re-read your material to place it into my "thinking' process.. and will try and find an explanation of what i'm saying... i don't think you and i are on "different' thought processes..

t-mack 5.90 2004 trials jump is my model... i think it was better than many of bubka's jumps.. the best ever jumped technically with the right pole flex, right bend, right grip height and right speed on the swing..

i do feel bubka's major mistake was trying to use to big of a pole flex...

i'll try and explain later

dj

[Skyin' Brian]

The equation for kinetic energy generated during the approach is



KE = 1/2 (m) (v)^2

m= mass
v= velocity


Though v is more important than m it is still part of the equation. Additional mass adds to the final result of the equation. Is it wanted, well not if you can't move it.


Plus momentum = (m) (V)

The momentum you take into the plant once you leave the ground is your mass times your velocity. If you carry more mass you have more momentum to over come the inertia the pole has to resist its bending process.


Once again I am not saying mass is overly important or should be the focus. No, but if you can still have top end speed on the runway of 9.5 m/s or faster and your carrying more mass and it doesn't slow you down. You have an advantage as far as generating KE and momentum into the takeoff.

i still done see why weight matters, sure, you generate more energy, that makes sense, but then it takes more to get you up to those heights, because your pole has to lift that extra weight. i think the fact that you think weight helps is simply due to its correlation with a vaulter's height

[Mecham]

The equation for kinetic energy generated during the approach is



KE = 1/2 (m) (v)^2

m= mass
v= velocity


Though v is more important than m it is still part of the equation. Additional mass adds to the final result of the equation. Is it wanted, well not if you can't move it.


Plus momentum = (m) (V)

The momentum you take into the plant once you leave the ground is your mass times your velocity. If you carry more mass you have more momentum to over come the inertia the pole has to resist its bending process.


Once again I am not saying mass is overly important or should be the focus. No, but if you can still have top end speed on the runway of 9.5 m/s or faster and your carrying more mass and it doesn't slow you down. You have an advantage as far as generating KE and momentum into the takeoff.

i still done see why weight matters, sure, you generate more energy, that makes sense, but then it takes more to get you up to those heights, because your pole has to lift that extra weight. i think the fact that you think weight helps is simply due to its correlation with a vaulter's height

I believe that the third phase of the vault is to make the recoil faster and easier. If you dont do anything during that phase, the pole will have to "lift" your weight. If you take advantage of the 3rd phase and make something out of it, theoretically your weight doesnt matter

[ADTF Academy]

Once again this goes back to the point I made previous. Do you beleive in the big bottom arm and moving the apex of the bend. If so then the lifting does occur and additional weight would require additional force to lift it.


If you beleive in pole rotation and trying to stay as close to the pole cord as possible and swing to inversion around this invisible pole cord. Then the amount of weight your carrying has little effect on the uncoiling process. Your along the axis of the stability point (for use of better words at the moment)

Once the pole has the energy it needs to rotate (which is increased if your weight is larger. Takes more force to rotate and object with a greater mass attached to it) then the remaining energy is stored as strain energy which will be later available as potential energy to be used by your body to be launched into the air.

During the uncoiling process if you set yourself up correctly your basically for the most part and use of better words weightless.


The old notice of pulling yourself up the pole is a falicy. You simply want to stay in line with the pole cord so that the strain energy is put into your body. The top arm pulling or bicep curl motion on the top of the pole is not to launch you into the air per say it is to move so that you can allow the pole's strain energy to be converted into kinetic energy to launch you into the air for your flyaway.



In the end is mass important maybe not as much at velocity. but 8kg (88kg of britss minus 80kg of bubka or 12kg multiplier if you compare hartwig to bubka of 92kg to 80kg) is a good size multiple in any math equation.

If you can carry the speed the additional weight isn't goign to hurt you. Am I am saying it is wanted, NO!!!! But it is a factor to the Kenetic Energy equation and to overlook it is nonesense.

Look at some of the professional linemen out there, Dewight Freeney for an example. 4.4 40 at 275 plus pounds. Thats a lot of momentum coming at you. OUCH

[ADTF Academy]

that swing velocity is a carry over, created by, the horizontal velocity the vaulter creates at the plant onto the pole and how fast the "bending and un-bending" of the pole takes place... the angles play a major roll as does the length of the "cord" of the pole during pole rotation.. shorter cord faster rotation.. faster swing speed.. potentially higher above grip...

I feel an issue that is misunderstood or not looked at is this. When the pole bends it shortens the pole cord. As it is bending/shortening it is also trying to unbend/lengthening. As long as the momentum and KE you applied in the pole is great enough it will continue to shorten. Once this has deminished to 0 it will start to lengthen.

With a swing vaulter and the notion of staying as long as possible during the entire swing. It does two main things. First it increase Angular Ineritia or the resist to change. Yes angular velocity as a whole in your swing is decrease making your swinging to the "L" or "U" position acheived with less velocity.

However, since from the start you were not holding your hips back as the pole shortened and you began your swing sooner you actually reach this position sooner than a powervaulter (big bottom arm)

Hence why they have to tuck to increase angular velocity to reach the "L" or "U" position as quickly as possible to get into a position to use the pole later in the vault.


The main issue is this. Once you tuck into this ball or increase your angular velocity. The Amount of angular inertia you maintain is decreased proportionally.

Now because of this there is resistance of the pole to lengthen and the pole uncoils very quickly. A sling shot effect. You went from a long bodied object hanging for the top of the pole to a curled up ball on the end of the pole.

I beleive this lengthening process in some cases is to quick and the vaulter can't get into position quick enough to use this lengthening whiping velocity.

I think this is why DJ wrote that Bubka might have been on to stiff of a pole.

I don't know if I agree 100% but I never had the chance to watch him jump enough on different stiffness poles.

I will say this that I agree with DJ though that just because you can get on a 12.0 flex pole doesn't mean it is goign to help you. If it uncoils to quickly for what your trying to accomplish than it is a waste of stiffness.


This is why I beleive the stiffness of poles Hartwig and Brits where on match their technique at the time. Hartwig was a big Tuck and Shooter and he wanted this very fast uncoiling process. He probably knew he was never goign to get inverted so he wanted to be launch/whiped as high as he could.


Bubka on the other hand wanted to get next to the pole in a completely inverted position before it uncoiled and then behind the pole (runway side) as it finished its lenghtening process so utilize all the strain energy that was converted to potential energy and evantually utilized by Bubka as kinetic energy to complete his flyaway and clearance.

IF you using any variation of the Continuous Chain Model, Eastern European Model, Petrov Model, 6.40 model, blah blah blah what ever you want to call it. A stiff pole is only as good as your ability to use it. If you can't get on top of it before it unbends your not taking advantage of it completely. Your slimply falling off the backside of the pole.

[dj]

good morning

well said...........ADTF

when a vaulter goes up a pole they need to have more horizontal velocity, to bend that pole to a "cord' radius close to the radius they "rotated" on the previous jump...(unless the previous pole was already way too soft) this is one of the reasons the flex numbers need to be closer and closer together on the bigger poles..

look at tim mack's 6:04 jumps at the trials.. he almost got it on his first jump....his second jump was on a bigger pole, a little too big, and he could not shorten it enough to "swing' the radius to vertical.. in other words he didn't penetrate..

i think that is what happened to bubka when he went to too big of a pole.. maybe on his best days he could move it.. but normally not..

here's a thought from my fishing days.. and how fishing poles are made.. and i actully tried this with Tully at a meet in irvine.. 1984

it does pretain to pole bend

theory... 1. the flex(stiffness) is what lets you penetrate, and lets you into the pit ..... 2. the length of the short side of the sail piece is what "picks" you up and takes you vertical!

for example a fishing pole with a stiffer/longer ridge.. sets the hook faster and stronger..

for example you are using a 12.5 flex with a 60" short side (ridge).. you are going just a little deep... you change to a 12.5 flex with a longer ridge, say 70".. it still lets you into the pit.. but takes you vertical quicker.. same flex stronger ridge....

on the big bend subject.... too stiff of a pole will make the vaulter use too much of the horizontal "force' just to bend the pole leaving little to swing with.. and will not allow the radius to be shortened enough to be swung into the pit..

all things being = it is easier to swing a 11' radius into the pit than a 13' radius... and in my opinion and experience todays spirits will bend with the right run and plant technique to 30/32%

in 1983 bubka bent his pole 31% ... tully and bell were at 28% i saw that as a disadvantage and mike started jumping higher on what was considered softer poles.......bending more... jumping higher.... the improved technology of the poles is what allowed bubkand others to do that….

of course too soft will roll into the pit too easy and quick ... or break..

they have to be matched.. and the only way you will know for sure is if the takeoff is correct and the takeoff can only be correct if the run is correct...the run must be quick..quick..quick.. with the strides UNDER the body... the run can only be correct if the start, pole grip and pole carry are correct........

later

dj

[master]

all things being = it is easier to swing a 11' radius into the pit than a 13' radius... and in my opinion and experience todays spirits will bend with the right run and plant technique to 30/32%

in 1983 bubka bent his pole 31% ... tully and bell were at 28%

Hi dj,

What are the percentage numbers of? Is it the percent reduction in effective length?
(grip height straight pole - grip height bent pole)/(grip height straight pole)
What I mean by "grip height bent pole" is the chord length, top hand to pole tip.

- master

[ADTF Academy]

If I am reading DJ correctly and I think I am


he is referring to the % the pole shortened (bent) from its original length.

Hence a 17' hand hold defected 30% would shorten to roughly 12 feet when the apex is the largest.

A 16'4 hand hold defected 28% would shorten to roughly 11 feet 9 inch.


One thing I would want to look at though on those % was what length of poles was Bubka using in comparison to Tully and Bell. Cause if Tully and Bell where on shorter hand holds roughly than they actually decrease the pole cord more than Bubka, which in my opinion is way too short if your %'s are correct.


Also with DJ's comments, first off this must be stated, that if you can handle and utilize the uncoiling strain of the stiffer pole. Meaning you can actually get on the top of it and beat the pole to inversion due to generating enough angular momentum during the middle of the vault and not doing anything to cease this momentum to inversion such as tucking.

Then the stiffer pole would also work the same in the other direction not allowing you to overbend the pole. Hence you would get a smaller bend in the pole so it increases the overall rotation distance giving you more time to prepare fo the top of the vault. The only issue with this is that the pole will behave differently and snap back quicker if you are not continuously providing energy into the pole during the entire vault (once again back to my bottom arm posts), which is only wanted if you can beat the pole to inversion and it doesn't snap out under you. This would happen if you providing any additional force or movement with the top arm keeping the hips down slowing your bodies rotation and the poel kicking your butt.


I think this is the opposite theory or mindset of most, Most get on stiff sticks because they are big, yet they can't beat them to inversion so it does them no good or they simply can't rotate them. As DJ said being on a slightly softer stick and using the bend more to their advantage would produce higher results for some individuals..


DJ excellent post though. Finally someone else goes out on a limb with me.

[dj]

hello

not sure why we are not connecting on this...

the poles are the same length and same grip.. bubka 30% tully/bell 28%..

that means bubka had a shorter cord to roll to vertical

peter mcginnis needs to throw in a note.. it was his data collection..

i took all the top jumps in 83/84 and ran my own analysis..

i found these things that stood out.. on good jumps..

1.. speed over the last 5 meters

2. step lengths were in a penultimate patter.. quick.. quick..long.. short..

3. amount of pole bend.. which means from pendulum/metronome physics a shorter pole cord can be rotated with less force.. ie.. same grip more bend shorter cord..

one of the reason steel poles limited vaulters was the height of the grip was limited because the "cord' did not shorten and then lengthen

4.. speed of the vault from takeoff to max height.. very important for the application of force to come off the top of the pole.. i think peter described it in another way

5. and height above the grip was greater on the vaults that had "pole speed" or a fast time from takeoff to max height.. under 1.5 seconds..


maybe this will help..

if you shorten the cord on a 16-5 190 to 12' and can swing it to vertical.. and move on to a 16-5 195 and shorten the cord to 12'9" how and were will you get the force to "move' that longer cord to vertical..

you can not unless you have moved the 190 past vertical or unless you have more speed, better plant technique, ie apply more horizontal force on the 195..

tully started maximizing the bend. He wasn’t as fast as bubka but was getting faster and had a tremendous swing… he had several jumps in the 19-8 range and with some improvements in his swing/invert.. much what t-mack is doing.. he and I felt if thingsa feel right 20’ was possible..

make sense

dj

dj