Will restringing change my poundage ?

[Trab]

Both my longbow and recurve need new strings. I will be taking them both down to my local archery shop soon. Having never had them restrung, I am wondering if the poundage will be matched after doing so.
Thanks for any help......
Trab

[bamboo]

in a word --nope--let it settle in and set the brace and you'll be fine
stomville huh--my old stompin grounds!!

[JamesKerr]

A new string should not affect anything after it is settled in and you get your brace height set where it was.

[L82HUNT]

If you go from dacron to FF your poundage will change.  Dacron will stretch more even a 28" draw yours limbs will not be bending as much.  A FF string will stretch less more limb bend, it could be a few lbs differance

[SaltyDawg]

Actually it depends on the elasticity of the string, and the strings elasticity memory.

Going from a string with a slower elasticity memory to one with a faster memory, can actually increase the draw weight as much as 4# even when the bow is set at the exact same brace height as the older string.

Example:
My BW PMA is 64# drawn to 29" with a 14 strand DF97 string on it. With a 9 strand UltraCam string, and the bow set at the exact same brace height as with the DF97, it is 68# at 29"

If you don't want to make any changes to your setup/tune, you better get a string just like the old one, or as close as you can get.

Rick

[Hud]

You should learn to do it and carry an extra string that is broken in (shot some) so you know where the nocking point and height is for each string.

If you buy 2 strings for each bow from the custom string makers they will be the same, and last longer, because the flemish loops will be made right and fit better.  I am not knocking the local shop, but if they buy their strings, they probably won't be the same quality IMO.    

[macbow]

I've never heard before of a 4# change in a bow weight with different strings and the same brace height. Heard of different arrow speeds. And changes,after stretching etc.
If that were the case folks could adjust a recurves bow weight by purchasing various strings.
Maybe it's a BW thing heard lots of different things concerning arrow spine etc.

[SaltyDawg]

macbow, it's not just a BW thing.

Has to do with the strings length at full draw.

A string with a faster elasticity memory will actually be shorter at draw than one with a slower memory, even though they are the same length at brace, thus it is bending the limbs a little more, and increasing the draw weight.

A bow (any bow) is at it's highest in line string stress when the bow is at brace, and at the apex of the shot. The string stress actually decreases as the bow is drawn.

Rick

[bamboo]

--please explain how you've been measuring the string at full draw--

[Pete McMiller]

I am finding this discussion very counter intuitive, almost to the point of disbelief, but, I'm trying to be more open minded in my old age and would like to learn more.  Where would I turn if I wanted to read up on a bow changing weight with different strings, string elasticity, etc.?

[macbow]

This is something very new to me.
Good explanation, but 4# worth of difference?
If the new string materials do change the game that much I 'd also like to read more. Also are there trade offs to the detriment of the bow?
Ron

[Blackstick]

This is interesting and something I've never considered before. It actually makes sense the way Rick describes it. This seems to be easily testable for someone with a scale and different strings.

Now, I'm wondering if there would be a difference between a Flemish twist and endless loop string.

[LBR]

Re-tuning is a good idea after changing strings, regardless.  You may need to make minor adjustments.

4# of draw weight equals over an inch of draw length with most bows--close to 2" with some.  Dynaflight '97 doesn't stretch anywhere close to that--especially not 14 strands.  Dacron won't stretch that much on a bow.  If there's 4# difference from UC to DF '97, then there should be something like 10# difference from UC to dacron, since dacron has tons more stretch.  Got to be something else going on there, or I'm reading it wrong.  

I'll do it again out of curiosity (out of town for the weekend), but I've measured the draw weight on my longbow several times with different strings--it's been the same as it was when the bowyer measured it with his tillering string (dacron I'm sure).

The draw weight can be changed a small amount with different brace heights, but not a big amount.

Chad

[SaltyDawg]

please, no offsite links to other archery forums

[LBR]

I'm trying to keep it simple.  A 4# loss in draw weight is equivelent to over an inch loss in draw length with that poundage bow, pending it doesn't stack like crazy (and I'm sure a BW doesn't).  Corrrect?

You aren't going to get 14 strands of Dynaflight '97 to stretch even a half inch, especially with just 64# of resistance.  On my jig, I can get maybe 1/2" with approximately 300# of resistance.  There's going to be practically no noticeable stretch with 14 strands with 64 (or 68) pounds of resistance at 29" of draw.  If you were loosing 4# just due to a DF97 string, then you should be loosing 10# or more with dacron--I don't see that happening either, as it's not going to stretch 3+ inches at draw.

There's just something that was overlooked somewhere--not hard to do.

Chad

[Pete McMiller]

Very interesting Rick, thanks for the link.  One question:  What is and how do you measure "in line string stress".

[bamboo]

how many shots on the strings before the testing??did you measure the brace after?

[LBR]

I must be missing something here.

"A bow (any bow) is at it's highest in line string stress when the bow is at brace, and at the apex of the shot. The string stress actually decreases as the bow is drawn."

How does a string stretch more when the stress is decreased?  Or am I reading this wrong?

[SaltyDawg]

Chad, your reading it wrong (I think).

The string/strings actually begin to contract/shrink as the bow is being drawn, and the inline stress starts to decrease.

The string with the fastest rate of contraction will be the string that yields the highest draw weight.

Of couse if you were to hold both strings at full draw for a length of time, they would probably equalize, but that isn't somethng I have tested. I know they have never equalised during the amount of time it takes to get the measurements.

Pete - inline stress is measured with a cable tensiometer, or you can do it the hard way, and use an inline scale on the string.

bamboo - for that particular test both strings were shot in strings. Probably several hundred shots on each. Yes, I checked brace height after testing, and it remained the same.

Chad - as a side note to this subject - If I build a string for someone, and the measurement they give me is from their relaxed string measurement. Even if I hit that measurement exactly, my string will be to short for them to use on their bow. Why? Because the string I build won't stretch as much on the bow as most others.

I did not intend, or want this to turn into a plug for my strings. I apologise, that it seems to have done so, so I will bow out now.

[Pete McMiller]

Thanks Rick,

I'm still trying to wrap my head around these concepts and may have to play around with my own set ups.  Some of this stuff just boggles my mind..........and I'm one of those anal retentive guys that that enjoys the minutae of the esoteric.

BTW:  I never thought it was about a specific string maker and didn't even know you made strings until this last post.