skinny string ?

[Nativestranger]

Thanks for the test foudarme. Looks like @28" there's not much to gain going below 12 strand. Now when you add center serving  to the finished string I suspect even smaller difference between them since you will need thicker (and heavier) serving to fit the skinny string to your nocks.

[DesertDude]

I'm with Chad............

[Nativestranger]

I will post the image here if you don't mind.
   
from arctradionly

[foudarme]

Originally posted by foudarme:
I have done a full test review in 3 parts on ATO the french tradgang like forum with a shooting machine and the same twisting ratio on 10 strings (8125 vs astroflight) I had carefully built before; only the number of strands was changed (16-14-12-10-8); each string has been stretched and stabilized before shooting (during a whole night for each 8125 strings) in order to get a regular brace height and zero elongation during the test; each string has also been weighted; no string has been served in order to avoid any bashing about any serving's weight issues; each string has been shot with a 6gr loop (what is quite near of the final weight of a 15cm .021 62xs serving ); the shooting tests has been done in 3 times: the first one I have shot all the 8125 strings and a few days later, all the astro strings in 2 times (astro strings test has lasted a lot cause everything had been done with a unique same string that I have untwisted and from which I had remove 2 strands at each time before twisting again, stabilizating and shooting...never again ! On these strings the twisting ratio has ended at 35 twists for a 60" string (with the new black douglas dx riser, the string is only 2" less than the bow length)).

the bow is my border black douglas recurve with hex6 wood BB2, 62" AMO, 57#@28" (yes! you will see how much the speed of this bow is crazy ! the brace height is her hunting one: 7" )

for speeds I have used a pro chrono with indoor infrared kit.

Each string is shot with 2 different arrows' weights (577gr ie 10gpp & 721gr ie 12.6gpp) and at 3 different draw lengthes (28" - 29" -30"); 2 shots by arrow and draw length if speeds are the same, if not, 3 shots and the average speed is retained.

brace height has been controled before and after all shootings for each string.

each shot has been done at AMO draw length (vertical projection of pivot point to nock groove + 1.75")

such a review takes hours knowing that before I have also done the strings (my wife was a stringmaker before falling sick so I know how to do a "little bit".)


As a conclusion, for making short, with top notch strings all of the same quality, the gain will be of 3fps max between the heavy 16 strands and the light 8 strands string and will depend on the arrow weight and the draw length. If you compare with a generic string, the gain will be mainly the difference between what you could get from a good string in comparison with what give to you a poor one, nothing to see with the number of strands of both of them.

On my recurve I have found huge differences in noise, vibrations and release stability according to the number of strands: the less strands you have and the less the bow is noisy and the less it will be poor release forgiving...

for the noise test I have used 2 extra ears pairs with innocent observers (my wife and elder son)! for release forgiveness I have used my poor own release !
                                                 http://www.arctradionly.com/t3769-combien-de-brins-a-ma-corde-partie-2#61149                

I think like Chad, for many bows, there is no real advantage to shoot at usual draw weights (50#-60#) strings less than 12 strands (for 125lb+ strength fibers; what is the case of the d97 - 8125- astroflight - d10 for instance) except, maybe, for your string maker who saves fiber for each string sold (at the end of the year 33% of less fiber used should make a comfortable difference!) and can hope for a shorter lifetime of your skinny string (because a 8 strands string will elongate much faster than a 12 according to the limbs' bow geometry and draw weight). 12 strands with these fibers (of course it would be different with 75lb strength fibers) appears to be the best compromise between noise, stability, shootability and speed...last but not least, if you use a 030 serving on your 8 strands string (cause skinny diameter strings hurt fingers and nobody want to be hurted!), the extra serving weight will eat 1 of the 2 fps you will have earned thanks to the strands number reduction !

Sorry for the tittle but in my country there were so much miracles advocated to skinny strings that I have choosen to retain this tittle which corresponds to a very famous "how to" books' collection in my country.

[Pete McMiller]

Thank you Foudarme.  That certainly was alot of work.  Your results are consistent with other data I have seen - there really isn't much or any increase in performance as measured by velocity.  That said, the difference in the 'feel' of a bow is very real as you have indicated.

We all know that not everyone is comfortable with every bow and much of that has to do with the vibration pattern at the shot IMO.  I have shot bows that rattled my elbow at the first shot and were, in my mind, unshootable until I changed to a skinny string.  Calmed that bow right down 'for me'.  Someone else could pick up that same bow and never have a problem.

I think everyone should try a skinny string and see what the effects are for them.  If it works great, if not go back to what makes you happy.

[LBR]

Thanks for the translation foudarme--your findings correlate with mine, and the people I personally know and trust who have done similar research.

I have also noticed a difference in feel and noise, but it only became negative with a very much overbuilt string.  Going extremely low in strand count didn't seem to be any better than a moderate strand count, for me at least.

Good point about durability as well.

Chad

[foudarme]

the more funny is when skinny strings become more expensive than normal one...I have seen it in a very famous bow maker house...less fiber = more usd...delightful...surely for R&D fees !