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Topic Date User

Rope - static v dynamic for top-roping and leading 31-Jan-2012 At 12:53:23 PM Hendo

Message

On 30/01/2012 One Day Hero wrote:
>Actually, I reckon I've got a pretty good argument as to why I'm right.
>
>With a slow pull, you can wrap the rope around your arse and sit on it,
>thereby getting your full bodyweight onto the rope.
>
>With Dan's "sharp tug", in order to achieve the same force you need to
>be able to grip a wet rope in your hands and hold it without slippage.
>
>I reckon I can do a chinup on a wet rope, but only just. If you strap
>20kgs to me, you can forget about it!

I think this is wrong. Firstly from a logical perspective if you can rest your body weight on the rope then you can surely bounce at least a little bit if not a lot and add some acceleration, thus increasing the force, with the increase being greater with a static rope.

Forces in dynamical situations can be surprisingly high, even just standing up reasonably quickly i'd estimate adding 50% to your weight force, try it on your bathroom scales, running is a few times bodyweight.

I have no doubt a static rope and some body movement allows you to generate forces significantly higher than static body weight leaning on the rope when standing on something solid. Swimming in a canyon trying to pull the rope at a low angle would be different, but then you couldn't just sit on the rope anyway, so you want something stiff to yank on.