String Stretch and Shrink

[Lashbow]

After a string(B50) is well shot in, over a year,I still notice an ever so slight amount of stretch. maybe a half twist every couple months and my BH is back.
Once, while headed out hunting, I unstrung the bow but left the top loop on the limb, so it would not untwist at all. This was because it was around 75-80 degrees and it was in the car, windows open. It was not really that hot in the car.
For good measure i brought my stringer and bow square. and braced the bow. To my Surprise my BH was a good inch higher???
I dismissed it as some strange fluke.

I usually leave my bow strung and hung on a rack because I shoot it enough.
recently I decided to un-brace it for about 2 weeks. same thing here too, top limb holding the loop, and the bottom tight in the nock groove.

When I braced I was about 1/2" high on the BH?
it stretched back over the next couple days and about 30 arrows.

Is this normal? I dont dare unbrace my bow again.
I am afraid after all this stretching and shrinking my nock point will wander.

It is a flemish string 15 strand B50.
62# at 31"

I can shoot a no creep string but chose a B50 to be quiet. I have no real experience with a different material.

I did not make this string, but it was new with the bow.
I have made my own strings with similar but inconclusive results.

What do ya'll think?

Lash

[Bruinbow]

I have found if you back lay the tag ends before laying the loop B50 will not creep . The thing you are seeing with the BH is B50 will get air between the fibers and can take a while to streach out . The twist of the string will cause the problem , tight twist more streach , slow twist less . I like to keep my twist to less than 3 in 2in. I shoot a 15 strand 60# and my BH can be +1/4in but will settle in in about a half hr.

[Nativestranger]

The creep is present in a Flemish string regardless of material.  I have a 10 strand B50 that doesn't creep ever after the first 50 arrows. And I have flemish Fast flight strings that keeps creeping and needs more and more twists to keep the correct brace.

[Lashbow]

What do you mean back lay?
I do know I have a fairly tightly twisted string, so maybe I will shorten it a bit.

[LBR]

Is this normal?

Yes.

 

I can shoot a no creep string but chose a B50 to be quiet.

With proper tuning and silencer placement, you can get a "FF" type string just as quiet.

 

What do ya'll think?

All string materials have a degree of stretch (elasticity) and creep (permenant elongation).

How much depends on a few variables--strand count, draw weight, temps, string construction, etc.

One of the main reasons I prefer low stretch materials is just that--low stretch.  I'm not worried about a few fps--if I were, I'd choose a different weapon.  Any increased performance is just a bonus, but I'd use these materials even if they were slower.

Endless strings will generally have a little less initial creep, but that won't change the characteristics of the material.  A rubber band stretches, regardless if it's twisted or not.

I try to leave my bows strung.  Even though they have low stretch materials, even those retract a bit when the tension is removed.  If I have to un-string, I allow time and/or shooting to get them settled back in before I have to make shots that count.

It shouldn't cause your nock point to move.

Chad

[Bruinbow]

Back lay is hard to describe but easy to do . You know how you lay the bundles by twisting and letting them lay like rope on each other when you make the loop ? When you have the length that you want and you are ready to lay the bundles on the main string , clamp with some kind of clamp or spring clip and twisting the opposite way that you did the loop lay the tag and the same color together but reversed down to the first strand . Clip a small paper clip and do the other color bundle the same way . Then lay the two bundles the same direction as the loop until you cant go any farther because of the paper clips . Remove the paper clips and finish the lay about 8 turns past the last tag . it really is not tough , just hard to describe . I do the same thing with a 3 bundle but that can get clumsy . I do all my strings and my friends , none of them creep after a short break in period .