How to determine if a bow string is too stretchy or too stiff?

[wizardgoat]

Invest in a spool of fast flight and never worry about string stretch ever again

[osage outlaw]

I agree with the Goat Wizard. 

[Bowyer Wannabe]

I just made a string out of hemp twine. It's not Flemish twist or continuous loop, nothing fancy really, but it works and has zero stretch.
Problem is that it became rather bulky and heavy.
Which brings me to my next question: how heavy is too heavy for a bow string? We are talking 40# bow here.

[Badger]

      I use a lot of linen strings, the linen is fairy expensive but the cost per string is fairly low. I pay about $ 28.00 per pound and I get about 35 strings. So it is still les than $1.00 per string. A linen string will not last as long as fast flight but I like to shoot bare finger and it makes just the right thicknes for this.

    The year before last at the flight shoots I shot a bow using fast flight and got 351 yards, I used the same bow and same arrow with linen and got 341 yards. Not much difference.

[PatM]

All depends on how much cast you want to sacrifice in exchange for a safe margin against breakage.

[Bowyer Wannabe]

All depends on how much cast you want to sacrifice in exchange for a safe margin against breakage.

Well, I don't want to sacrifice much cast. I chose to go with a no-stretch string in order to gain some cast form my previous stretchy nylon cord string. Now, I do have a no-stretch string, but I believe it's too heavy and may be slowing down the cast. A Catch 22?

[PatM]

Did you determine what the breakage point was of a strand? You need to know that so you can figure out how much you can reduce the strand count.

[Bowyer Wannabe]

Did you determine what the breakage point was of a strand? You need to know that so you can figure out how much you can reduce the strand count.

I did some "let's see if I can break this strand with my bare hands" type of tests, but nothing too accurate.
I have weights that I use for weight lifting. I guess I can use them to determine the strength of the hemp twine. Any formulas that I should use for this? I mean, how much stronger than the draw weight of the bow should a bow string be?
Thanks!

[Pat B]

I'd say, buy a 1/4" spool od B-50 bow string. It is relatively cheap and is made for bow strings. Later you may decide to go the Fast Flight route but for now a $9 spool of B-50 will get you quite a few strings to start with. If you decide to go with FF I'll trade you for the remaining spool of B-50.   

[loon]

Isn't hemp much lighter than polyester/etc for the same thickness? I'd like to try long strand quality hemp with Knox glue or some other more flexible glue. Maybe monofilament serving or something thick and solid to prevent kinking at the drawing point. I think I like to use masking tape :p Would I ever expect a good hemp string to last years with a 60# bow? Wonder how it compares to leather or rawhide strings..

A good thing about thick strings is that they're easier on the fingers. But I guess a thick serving can do that just as well.

I made a thin processed craft store hemp string and it broke at a loop, just under where the Turkish loop was tied to the main string with a ~35# bow. Hmm. A rather thick and overbuilt one with similar draw lasted pretty long.

Seems like silk strings were about stretchy as Dacron, and historically highly regarded. Used by Turks and Koreans in their composite bows. Non-twisted, pre-stretched Dacron/polyester strings seem just fine... I imagine it'd be the same with silk. I read of someone who built silk strings by leaving weights hanging from each strand near their breaking point to pre-stretch them. Something similar could be done with Dacron/Polyester!

Nylon is very stretchy. Not sure how to determine if a string is too stretchy, I think the most obvious way is see if you have handshock. If you don't have handshock with your strings, I'd say you're fine.