# Theraband© properties changed?



## aiping (May 31, 2016)

today I tried to reproduce my record shot with
the approved ChronoConnect standard procedure, 
but immediatly I found that the 'Sound 'was wrong: 
I could distinguish shot and impact which was not 
the case 2 month ago! And Yes:

ChronoConnect showed following results

1 x TBB (black) 9 x 3.5 cm taper/ 23 cm /
135 cm draw
- 9.5 mm steel 310 FPS
- 13 mm steel 300 FPS....!

So I changed the bandset:

2 x TBB (blue) 9 x 3.5 cm taper / 23 cm /
135 cm draw
- 9.5 mm steel 300 FPS
- 13 mm steel 290 FPS....!

Its like hitting a speed ceiling, draw weight is correct!
Taper, length and draw too. Very puzzling.

All penetration tests on wood I still have failed,
max penetration on foam now is 3 layers:

http://slingshotforum.com/uploads/monthly_08_2016/post-17169-0-34516500-1472042009.jpg

before 5-6, (7 record).

So, the air became thicker,.. or Theraband properties changed!


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## Bugar (Dec 24, 2009)

I imagine it is the humidity, when it is higher, more moisture is actually in the air, so the air is THICKER, and the humidity changes constantly.


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## honorary pie (Feb 12, 2015)

well, temperature has a huge impact on speed, as do band setups and draw consistency.. if you are using foam for a backstop and no target, I have to doubt that you have been shooting slingshots long enough to have developed a perfectly consistent draw length, which has a huge impact. also, your bandsets for that ammo are quite innefficient, and you didn't provide us the comparable data from two months ago.. the biggest point though, would be that 10fps is only a 3% difference at 300fps, which is a result that can vary in greater numbers between sunrise and the afternoon. also, your release time can affect your speed by as much 10%. I wouldn't fret over it much. sometimes I notice a speed drop when working in a new bandset, but then I remember that there are just so many variables. Two people with the same bands and draw, may achieve different speeds, based on their technique alone.....


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## aiping (May 31, 2016)

Thanks for info that humidity has such 
big impact and that my draw length
probably is still quite inconsistat.
To the pictures, the two balls and 'dents'
you can see are recent results, the rest is
done two month ago.


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## honorary pie (Feb 12, 2015)

I think perhaps it'll sort itself out after a few thousand rounds, because it can vary so much from shot to shot, I wouldn't get hung up on power just yet. is this a comparison between blue and black as well? Because these are two totally different animals.. blue will almost always out perform black with those dimensions.. until your ammo get's heavy anyway.


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## aiping (May 31, 2016)

That's why I am so puzzled! Blue isnt't faster and
8.4 gram 13 mm steel just 10 fps slower than 3,4 gram
9,5 mm steel, blue and black. These values are completely nuts. For real is that now harvested energy is about 50% less than before. That has nothing to do with humidity
or draw inconsistency.


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## aiping (May 31, 2016)

After several tests the performance drop of my batch black & blue is confirmed.

If you face the same problem I suggest:

9 x 3.5 cm taper / 26 cm length

- BLUE => draw 150 cm for 9.5 mm steel will give you around 350 fps / livetime around 20 shots

- BLACK => draw 135 cm for 13 mm steel will give you around 300 fps / livetime around 30 shots


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