Skinny fast flight strings W/padded loops on non fast flight bows?

[Rob DiStefano]

chad, skinny hmpe strings are EASIER on bows than hmpe strings with 50% more fiber in the bundles.  i've proven to myself they are ever so slightly more elastic.  

then again, all the twisting in a flemish bowstring will always impart a "springy" factor that could never be achieved by an endless super low twist bowstring.

all you folks that are proposing testing, fine, have at it, this is great!

but since none of you have stood next to an old bow that blew up with a fastflight bowstring, i doubt you'll ever have the same perspective of those who, unfortunately, have.

and lastly, who will police what old bows might be capable of handling a dyneema bowstring?  what criteria will you use?  how will you know what to do???  the answer is obvious.  don't take chances and ymmv.

[Rob DiStefano]

Originally posted by pavan:
Now you guys have gone and made me nervous, so I made a Dacron to go on my Pete George that had a fast flight. I could see no nock damage on it yet. I have a Hill that does not have the end cap, just the wedge, that I have a padded fast flight.  It is 68" long and I draw it to 58@ a 26 plus draw.  Should I be concerned about that one too? The Pete George Yew fiberglass bow has no more hand shock with my B50 than it did with the FF, it may be a couple of FPS slower, but not enough that I can tell.

no one's gonna stick their neck's out and tell you what to do, just make the safe choice and feel better.

for me, hmpe strings are NOT ABOUT ADDED ARROW SPEED.  they're about consistency of brace height under all conditions.  ALL my longbows use low strand count hmpe endless bowstrings with padded and served loops.  then again, all my bows were made in this millennia, and to my specifications.

[tecum-tha]

Rob: Energy doesn't flow in bows. Energy is mechanically stored in bows, on release, some of this energy is used to accelerate the limbs (the heavier the limbs, the more energy is "wasted"), another part of the energy is tranferred to the arrow and the unused mechanical energy remains in the system. Now this mechanical residual energy tranfers into vibration. With a dacron string a part goes into the string and is used up by stretching the string and a part remains in the bow. This results IMHO in a shockwave with lower amplitude and lower frequency.
Skinny strings have usually the same tensile breaking strength than adequate dacron strings, but less mass. Traditionally the breaking strength of a bow string was 5-6 times the rated bow strength.
Now the hmpe skinny string will stretch less, and will transfer the amount of stretch energy most likely into the arrow, delivering a slightly higher arrow speed.
When the tips are stopping without stretch, the material stress at the bow tips may be up to 2.5 times as high as with elastic material. Creating a higher wave amplitude and a higher frequency.

Now, what is the difference between a modern limb and a limb of an older bow, besides the reinforced limb tips?

[Rob DiStefano]

roland:

of course "energy flows".  the bowstring transmits the stored limb energy to the arrow, that's the main "flow".  what the arrow can't absorb goes back through the string to the bow.

if a bow required a 12 strand polyester string (600-# tensile strength) and i use an 8 strand hmpe string (800+#), the low strand count string is still less elastic than the polyester string, but more elastic than a 12 strand hmpe string (1200+#).  for me, the low strand count hmpe string is "safer" than the full count hmpe.

you already know the differences between old and new bows.

[Don Stokes]

I've had one bow fail because of early FF use, my revered Archery Traditions Bamboo Longhunter. Fortunately is was salvageable, and Tom Jeffrey, who built the bows for Dan Quillian, was able to rebuild the tips. The problem was that Dan didn't realize at first that the loops needed padding to keep the FF from eroding the string grooves, which BTW were properly made. I was one of the first to use the FF on his bows. Tom put some harder material on the tips, which were originally walnut, and the bow has been shot thousands of times since, with FF with padded loops. The bow was built in '88.

Chad, your posts have been very lucid and reasonable, and no one should accuse you of feathering your own nest in your discussions, or advocating use of dangerous strings on any bow. You have done a very good job of stating your position, and I doubt that anyone who reads this thread would think it was OK to use low-stretch strings on bows not suited for them, based on anything you've said.

tecum-tha, thanks for your highly informed input. You obviously know your stuff.

Rob, thanks for finally saying what hmpe means.     I think your were a little rough on Chad, but I understand where you're coming from. Overall, this has been a good, informative discussion.

[Shawn Leonard]

Agreed, it allows people to make a more informed decision on the use of any string material on many different bows, old or new. I apoligize for coming off crass in my posts to Rob, but I hated to see this thread pulled as it is informative and may help people who were on the edge of making a decision on what to do or not to do!! Shawn