[ronan]

Hello everyone,

Just a litte but important question :

When some people on this forum speak about for instance streching bands to 400%:
Does it means that the draw length will be: 4 x initial length ?
Or does it means that the draw length will be: intial length + 4 x initial length = 5 x initial length

I think the first one is more curantly used but I ask this question because I saw the second definition used in a theraband data table. I know that Theraband use the second definition because a percentage below 100% does not make sens with the first definition.
I hope nobody has been misled by this subtlety.

Here is an example of discussion about % of draw with Joerg and Torsten.
Here is the Theraband data table :

 

[JoergS]

I use the factor method. 200% means that a 10 inch bands is drawn to a total length of 20 inches. Therefore, 100% means the relaxed condition.

The Thera chart is indeed using the elongation. Using that method, stretching 10 inches to 20 inches means 100%.

I find the Thera chart not very useful as they stop below the draw factors relevant for slingshots. Their target market is entirely different, so it is understandable.

For our purposes, the factor method is helpful as you only have to divide your draw length through it to end up with your band dimensions. 500% works well for a powerful TB gold setup (50-200 shots), so if you have a 30" draw, your active band length should be 6". If you want long band life, 400% is better, so 7,5" would be the length of the relaxed band (100-350 shots). At 300%, the shots will be much less powerful, but your bands will live 300-1500 shots.

The conversion is simple. Just add 100% to their values, or substract 100% from ours.

Jörg

 

[ronan]

Vielen Dank Joerg !

Deine Antwort ist vollkommen klar und vollständig.

(Thank you Joerg ! Your answer is perfectly clear and complete)

 

[ZDP-189]

I always mean 100% is doubled, not unstretched. It's "% elongation", not .% length".

If you're see someone say they're shooting at 400% the probably mean 400% unstretched length, because 400% elongation is a lot; probably enough to tear the bands.