swtvault wrote:Scientific analysis has proven the take-off angle of many elite vaulters to be between 10-20 degrees--which I would not call jumping up. Maybe I am missing something here? I understand in a perfect world that we would want to create a higher angle at takeoff, but I don't believe that the losses in horizontal velocity would compensate for the gains in vertical distance. BY this I mean that for every degree closer to vertical our takeoff angle is, we lose horizontal energy at an exponent rate. Its great if you can run 9.8 m/s, but if you blow your wad and jump straight off the ground how much speed are you carrying THROUGH the takeoff? Bubka jumped 6.15 because he could run 9.8m/s and he could carry that through his takeoff. There is a vortex where we fully utilize our horizontal energy, and vertical energy equally, and I do not see how creating the kind of takeoff angles we are talking about up can benefit us in any way. Please clarify if possible.
We are not talking about jumping straight up. More of a long jump takeoff, which is ideally around 19-22 degrees-- the lower end being right inside the range you just specified for elite vaulters. It is not supposed to be a breaking jump, but a cyclic one. I seriously doubt elite long jumpers lose speed at takeoff. Neither should pole vaulters who use a correct long jump takeoff.
It's not so much about a height advantage as a direction advantage.
By the way, Bubka could run 10.0 m/sec at plant. He also jumped up. Just ask him, his coach, or anyone who knew him. The fact that he was at 10m/sec at plant while jumping up should suggest that he didn't lose speed. This is also why he could long jump 26 ft.
Try vaulting with a straight pole holding as high as you can and not jumping up, but just running under it. Then try it with a correct long jump takeoff. See which makes it easier not to stall out. Also, see which makes it easier to hold higher.
I reiterate that the angle of takeoff can be inside the range you specified. There is no breaking action (which causes loss of speed) at plant in this technique if executed correctly.
The entire point of this is that the center of gravity is rising when the pole tip hits the back of the box, allowing for a much easier translation of energy. This effect is not acheived by simply running forward until the pole takes you off the ground.
If you want to talk about speed loss, talk about the speed loss that occurs when the pole has to translate all the energy for you because you weren't rising at plant. You are not coming off the top nearly as fast if you are running straight through takeoff and the pole has to do all the lifting.
If you are rising while still traveling forward at plant, you are carrying at least some of your runway speed directly to the top.
This is just my opinion. Just trying to answer your question as best I can. Hope it helps.