# Optimize Your Bands.



## Henry the Hermit (Jun 2, 2010)

I promised this a long time ago, on the Chinese tubes topic, but just now got around to doing it. This will work fine for the cowboys who like to see big numbers on the Chrony or want to break concrete blocks. For normal people who just want decent performance, forget all this nonsense and cut your bands for a stretch factor of 4 to 5.

This will work with any kind of rubber you care to use, but I used Alliance Sterling #107 rubber bands for this how-to.

Here is what you will need.

1 board about 3 to 4 feet long
1. short piece of board
1 large "c" clamp
a marking pen
a tape measure









I used two pieces of 1x2 inch board to jury rig a clamp. Put the end of the cut 107 between the two boards and clamp together.









Mark the rubber. I chose 6 inches, but you can use any convenient length.









Grip the rubber at the mark point. Get a tight grip.









Stretch the rubber as far as you can.









Mark the board at the mark on the band. Be sure the rubber is stretched as far as possible. Now measure from the clamp point to the mark. In this case I stretched the 107 from 6 inches to 35 inches.









Now that you have the two numbers, divide the stretched length by the relaxed length. 35/6 = 5.83. That is the maximum stretch factor. All you need to do now is divide your draw length by that factor to find what length band will give maximum power. If you have a 32 inch draw, then 32/5.83 = 5.48 inch. This is the length from the fork to the pouch tie. When you measure your draw length, measure only the rubber, do not include the pouch. Also bear in mind that some rubber, and 107s are one of them, will grow as they are repeatedly stretched. This will result in an apparent "softening" of the rubber, and is caused by the rubber getting longer.

In practice, you may not be real happy with stretching a band set to its absolute limit every shot, so I recommend cutting bands to a bit longer than optimum. I cut mine to about a half inch longer and get much improved band life. You can always keep a few optimized bandsets on hand for when you want to show off.


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## rockslinger (Nov 16, 2010)

Good information Henry, thank you!


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## Stevotattoo (Jun 28, 2012)

Really helpful and very informative...thanks Henry


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## orcrender (Sep 11, 2010)

Very clear and well shown.


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## Jakerock (Mar 8, 2012)

Thanks Henry!


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## treefork (Feb 1, 2010)

Nicely done Henry.Straight forward and logical.


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## Charles (Aug 26, 2010)

Good information, Henry. Perhaps this should be placed in the Tutorials section ... What do you think?

Cheers ....... Charles


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## jonathanfv (Aug 29, 2012)

Neat idea! I'll try that at some point.







Thanks!


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## Henry the Hermit (Jun 2, 2010)

Today I cut a pair of 105s (shorter version of 107) using the above formula. This is the first time I have actually gone for maximum performance with these bands. I learned a valuable lesson. Not all rubber can withstand being stretched to the max for very long. This set lasted about 20 shots before breaking at the fork. So, while the 107s are OK for illustration purposes, I do not recommend cutting them this short. Try something between 4.5 and 5.5 stretch factor, instead. Anyway, if it's max performance you want, 107s aren't the best choice. For what it is worth, I did see 210 fps with .44 cal lead before the band broke.


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## pop shot (Sep 29, 2011)

That's impressive- 210 fps with 44 cal lead and 105's/107's!!!


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