Setting the Record Straight - String Material

[LBR]

There's been some controversy over certain string materials and some bows for quite a while.  While I know this won't change any warranties and won't sway some opinions, here it is...

I just returned from an event where I was able to spent a good bit of time with, and pick the brain of, Jim Cass.  Jim is probably the single most important person in the bowstring fiber industry in the word.  He's worked at Sampson Rope for 40+ years, and can tell you anything you want to know about fibers.  They supply naval rope to 14 different countries, amongst many other fiber applications.  They have almost unlimited resources when it comes to testing, from the greatest minds in the industry to the most high-tech equipment.  To say he knows his stuff is like saying the Wensel brothers have killed a deer or two, or Howard Hill was a pretty fair archer.

To get to the point, I was discussing bowstring material with Jim off and on for a few days.  The big controversy of late seems to be:  what is the amount of elasticity of one material vs. another?  The answer is simple, and was re-confirmed to me again last week.  The only material on the market that has any degree of elasticity is polyester ("Dacron").  Period.  None of the others have any noticeable degree, especially at the shot.  Some DO have a degree of elongation/creep, but this happens over time, under a load, and can be affected by higher temps.  

Again, this won't change any warranties, might not change any opinions, I just wanted to put it out there for anyone interested.

Chad

[T Folts]

Interesting for sure. That is good to know.

[Butch Speer]

Thanks Chad. pretty interesting stuff.

[Chad Orde]

Thanks for the report I bet that was a fun meeting for you! I’m an engineer and it’s always great to talk to the top of field person and get set straight. Thanks again for sharing.

[katman]

Thanks for the info Chad. Your right, probably won't change opinions of some but nice to hear info from informed sources.

[LBR]

I've known Jim for several years, but generally only get to sit down with him at one or two events a year.  He's working on getting me some "official" documentation/references that can be displayed to the public.

I know he's straightened me out on misconceptions that I had.  One of the big ones that seems to confuse lots of people is stretch vs. creep.  Stretch is elasticity, like a rubber band...elongation that immediately recovers.  Creep is elongation that happens much more slowly, over time and under a load, and doesn't fully recover if at all, and certainly not at draw or in the instant a bow goes back to brace after a shot.

[Roadkill]

Worth the read thanks. Confirms what i was told.  Creep vs stretch is a very important aspect of our sport

[limbshaker]

So basically the blends with Vectran (?)  (like BCY-X) shouldn't be any rougher on limb tips than any other blend without it. Since even straight Dyneema blends don't have any measurable elasticity.

I assume that finished string diameter in the loops could have a bearing on that, so let's just say they all have the same finished diameter in the loops.

I could believe it. Thanks for the info, I'm always interested in stuff like this.

And the BCY-X string you built me hasn't sheared off any limb tips yet! Works great!

[LBR]

Exactly, or if it is more harsh it's not due to elasticity or lack thereof.  I've been using BCY-X on a Samick Journey (64" version of the Sage) for going on 7 years I think.  Bought it when BCY-X came out, just to test the material.  The bow is no worse for the wear, at least not from the string.  Shoots great with a good string on it.

[limbshaker]

[joe vt]

This makes sense to me because I have some bows where putting a Dacron string on makes the bow feel smoother.....elasticity in action.

[Orion]

That's sort of what I've been thinking for awhile.  Of course, that means that there's really not much difference in the various  low stretch materials. Shot in (which doesn't take very long and maybe only a few arrows if the string was properly stretched when made), they'll all perform pretty much the same, though some may creep a bit more than others.

Does that mean I've saved a pile of money by sticking with D-97 and not not chasing/buying every latest iteration of low stretch strings that came along?

[Jasper2]

Not in my opinion Jerry.  I may not understand the science behind it, but I do know that every single bow that I used to shoot D97 on, shoots noticeably better with one of the higher grade materials.  

I don't know why certain bows prefer certain materials.....but my testing definitely proves this fact time and time again.

What are the elasticity or stretch variations from an endless string to Flemish string?  I have been wondering if even the Flemish strings have variations. Like two or three splines of minimal strands versus extra strands with padding or a string that has minimal twists, versus one that needs extra twists that may be needed for brace height adjustments..

[Orion]

Agreed, Jason.  I was being somewhat faceteous.  A lot of folks over the past few years have reported what they consider noticeable differences between the various low stretch string materials.  Has to be something to it.  

When I use up my D-97, I'll be trying a few others.

[LBR]

Performance, when everything is equal, will be very similar between materials.  There's not even a big difference when switching from dacron to HMPE if the build is otherwise equal.

The benefits are durability, stability, consistency.  Some have a small leg-up over others.  The build, tuning, and release are the major factors when it comes to noise and performance.

Although there are some top shooters using BCY-X, the majority of serious target shooters are still using 8125.  Dynaflight '97 is still a very good material.

The "feel" is subjective.  I seriously doubt there's a dozen people alive who could tell 8125 from Dynaflight '97 from Mercury from BCY-X just by the feel of pulling the string back...even a half dozen.

Although a flemish string may remind us of a spring due to the way it looks, HMPE isn't steel.  It has no temper, so it doesn't act like a spring.  Flemish will generally have more initial elongation due to the twist retaining more air/wax/slack, but once removed the material itself has no elasticity.

Yep, I've always told folks that there really is no "stretch", but that as the string settles by the bundles closing in on one another and pushing out wax it will get just a bit longer. I guess I had it right!!!

Bisch

[LBR]

Some materials do have a degree of "creep", which is elongation that occurs over time under a load and won't fully recover if at all...but most of the elongation you get from HMPE and HMPE/Vectran blends is the slack and air and wax.

[Orion]

Thanks for the facts and perspective, Chad. Given there's little difference in performance among the low stretch strings, individual preferences seem to be based on other things like noise, perhaps string thickness, etc.  Too, some folks just might be reacting to differences in build (some better than others) rather than differences in material.  And, of course, none of us is totally immune to seeing/believing what we want to see or believe.

[LBR]

In my opinion you are right on the money Orion--the build is the biggest variable IMO.  There are differences, mainly between 100% HMPE and blended, but in the same category the differences aren't so noticeable for the average shooter, at least in a finished string.