SBD "Skinny String" Question

[Rob DiStefano]

Originally posted by Javi:
Ok... skinny string aficionados I got a question for you....

I have a longbow which shoots a 658 grain arrow at 150fps; this bow is quiet, shock free and fun to shoot, the bow is equipped with a 16 strand Flemish string made of BCY D-10 material...  What is the practical gain in FPS I can expect with an 8 strand string of the same material...

dunno.  i'm not interested in speed but i am in it's cousin, trajectory.  one will increase and the other decrease.  a flatter trajectory might be a good thing.  for me, low strand count strings aren't about speed, but about quietness and "forgiving".

[Javi]

Originally posted by Rob DiStefano:
 

Originally posted by Javi:
Ok... skinny string aficionados I got a question for you....

I have a longbow which shoots a 658 grain arrow at 150fps; this bow is quiet, shock free and fun to shoot, the bow is equipped with a 16 strand Flemish string made of BCY D-10 material...  What is the practical gain in FPS I can expect with an 8 strand string of the same material...

dunno.  i'm not interested in speed but i am in it's cousin, trajectory.  one will increase and the other decrease.  a flatter trajectory might be a good thing.  for me, low strand count strings aren't about speed, but about quietness and "forgiving". [/b]

So then, if my bow is both quiet and forgiving I have no reason to change... Is that what you're saying..

I doubt I would change if there is no appreciable gain in speed from the skinny string.. all other things being equal it is much easier to build a 16 strand string....

[monterey]

 Depends on the string maker. If you go by AMO specs, the string should be measured under 100# of tension (except for dacron strings made from 10 strands or less--they get measured under 50# tension).

I think it's further defined as having the loops around a 1/4" diameter rod.

[LBR]

I think it's further defined as having the loops around a 1/4" diameter rod.

That is correct--I forgot that part.  It's all done in a way that can be consistent from one person to the next.

Since most don't have a jig to stretch and measure on, it can be done on the bow and get the measurement very close.  When measureing on the bow, check the brace to be sure it's correct--strings that have been off the bow for a while will usually contract,and will need to settle back in.

Chad

[Rob DiStefano]

Originally posted by Javi:
 

Originally posted by Rob DiStefano:
 

Originally posted by Javi:
Ok... skinny string aficionados I got a question for you....

I have a longbow which shoots a 658 grain arrow at 150fps; this bow is quiet, shock free and fun to shoot, the bow is equipped with a 16 strand Flemish string made of BCY D-10 material...  What is the practical gain in FPS I can expect with an 8 strand string of the same material...

dunno.  i'm not interested in speed but i am in it's cousin, trajectory.  one will increase and the other decrease.  a flatter trajectory might be a good thing.  for me, low strand count strings aren't about speed, but about quietness and "forgiving". [/b]

So then, if my bow is both quiet and forgiving I have no reason to change... Is that what you're saying..

I doubt I would change if there is no appreciable gain in speed from the skinny string.. all other things being equal it is much easier to build a 16 strand string.... [/b]

if i had yer exact setup, i'd wanna see if an 8 strand dyneema bowstring made for less of a trajectory at reasonable long hunting distances of 20-30 yards, while offering low noise and some measure of "forgiveness".  if 'yes' on the trajectory factor, i'd change and if 'no'
i'd evaluate noise and "forgiveness" and go from there.

[Flying Dutchman]

Originally posted by Javi:
Ok... skinny string aficionados I got a question for you....

I have a longbow which shoots a 658 grain arrow at 150fps; this bow is quiet, shock free and fun to shoot, the bow is equipped with a 16 strand Flemish string made of BCY D-10 material...  What is the practical gain in FPS I can expect with an 8 strand string of the same material...

I don't have all the info I need to answer that question. I did some tests here. As a rule of thumb your speed gain would be like something 1 fps per strand less. That is for recurves/hybrid/r/d long-bows, between 9 to 10 gpp and around the 50 lbs. And with a SBD D-10 string.
When you are saying 658 grain at 150 fps I think you are either shooting heavy arrows or a straight limb longbow? What is your drawweight?
I think your maximal gain would be 8 fps. The SBD site is stating between the 8 and 11 fps.

[Flying Dutchman]

Originally posted by elk nailer:
I bought a "skinny string from Abe Penner in K-zoo last year and put it on my take down Caribow. Really loud. Did not like it and took it off.

That's funny. I put a 6 strands SBD on my Caribow one-piece and it is dead quiet!

[Javi]

Originally posted by Flying Dutchman:
 

Originally posted by Javi:
Ok... skinny string aficionados I got a question for you....

I have a longbow which shoots a 658 grain arrow at 150fps; this bow is quiet, shock free and fun to shoot, the bow is equipped with a 16 strand Flemish string made of BCY D-10 material...  What is the practical gain in FPS I can expect with an 8 strand string of the same material...

I don't have all the info I need to answer that question. I did some tests here. As a rule of thumb your speed gain would be like something 1 fps per strand less. That is for recurves/hybrid/r/d long-bows, between 9 to 10 gpp and around the 50 lbs. And with a SBD D-10 string.
When you are saying 658 grain at 150 fps I think you are either shooting heavy arrows or a straight limb longbow? What is your drawweight?
I think your maximal gain would be 8 fps. The SBD site is stating between the 8 and 11 fps. [/b]

658 grain arrow.. 48lb at 28.5" R/D Longbow..

[Flying Dutchman]

658 at 48lb at 28,5" 28,5 inch would lift the bowweight a little bit up, lets say 49 lbs. That means you are shooting with 13,4 gps. That explains a lot about quiet and forgiveness! I don't know if your bow is heavily R/D but I would guess that with that heavy arrows your gain in speed would be around the 4 to 5 fps.

[Javi]

Originally posted by Flying Dutchman:
658 at 48lb at 28,5" 28,5 inch would lift the bowweight a little bit up, lets say 49 lbs. That means you are shooting with 13,4 gps. That explains a lot about quiet and forgiveness! I don't know if your bow is heavily R/D but I would guess that with that heavy arrows your gain in speed would be around the 4 to 5 fps.

The bow is fairly high R/D and it is 48lbs at my 28 1/2" draw length.. that is measured not a guess.. I tuned the brace with a chrono and found that by lowering the brace from 7 1/2" to 7" even the bow went from 141 fps to 150fps.. a real time gain in speed, trajectory and momentum..  If I could gain a like amount from a string I would fiddle with making the skinny string.

What I have a hard time wrapping my head around is the real time gain from reducing the string weight by removing strands but adding it back by padding the 7 or so inches of center serving area... and 10 or so inches of twist back to 16 strands..

Oh well, guess I just need to get off my lazy butt and build one and test it..  

[Rob DiStefano]

every stick bow will have a range of performance as dictated by design, brace height, string mass weight and elasticity, arrow mass weight and spine.  there are lotsa things to tweak and compare for performance.  "performance" means arrow speed, vibration, noise and stability.  

the bowstring is the transmission, the arrow is the vehicle and the limbs are the fuel.  lowered mass weights increase speed, and that goes for limbs, strings, and arrows.  i have no clue as to what and if any amount of aerodynamics adds to the measured speed/performance of those items.    

all the words in the world don't hold a candle to personal testing.  do the testing and let yer personal results guide your choices of tackle.

[Bob Morrison]

spend the $20 and try a 6-8 strand and you will know. Until you try it yourself you will never really know.

[Javi]

Originally posted by Bowbldr:
spend the $20 and try a 6-8 strand and you will know. Until you try it yourself you will never really know.

:D    I'll just make one...

Although it isn't a real priority at the moment, I just thought some of you might have empirical data from real time testing..

[HB3]

I shoot the SBD 6 strands on several recurves. In testing with a conograph and decibal meter i have not noticed much change in velocity all things being equal but their is a large change in noise, the thinner string being quiter. To me this is more important than the velocity.

[AdamH]

Listen to LBR, he's been doin this probably longer than any on here, take the string off at brace, hang on a nail, stretch it straight, measure the length, it's that simple, measure the loops also, 8-10 strands FF or whatever low stretch string, Chad's strings are GREAT as Im sure so are others, but I'll go with expierence ... {padded loops of course} ...

[USN_Sam1385]

Wow.

Let me just say that Pierre has been working with diligently and patiently to get the perfect string for my bow.

He has asked me questions about all the specifics of my bow, verified my preferences and arrows that I am using, and even contacted the bowyer personally to make sure that string is the perfect 'fit' for my bow.

This man REALLY gets involved in his business. I am sincerely impressed. That is something that is hard to find in this day and age, and I am extremely excited to get my new string.

In fact, I will order two just because I like how this man does business.

[Flying Dutchman]

Pierre is one of a kind indeed!