? for the skinny string experts

[Jesse Peltan]

I'm using 8125 for padding.  10strands in the body is your problem.  6strands is good up to a 73# bow.  20strands is more than enough padding.  If you want you can use b-50 or artificial sinew for padding.  It can get tricky with the padding what you want to do is cut your padding strands and stagger them 1/2 from each other.  That way when you twist a string up the taper is already there.  What do you mean by slipping something over the loop before you close it?  Are you talking about serving it?  Something you can do is serve the loop and neck of the string with wool.  I do this for my recurves to quiet string slap.  It also acts as padding.
FlintRiverKen, I don't know where to buy one like I make.  It's not hard to make a string though.  There's a tutorial here on how to make a jig out of a 2by4 about 30in long.  You don't need a jig but it's nice if you make lots of strings so you don't have to measure out all the strands.  Go ahead and get an $8 roll of 70# artificial sinew. Use one strand for 14# of draw weight.  Artificial sinew is cheap and makes a good string.  Once you get the hang of it get some 8125 and twist up some strings.  I don't know the folks at SBD but go ahead an e-mail them and ask if they'll make one.

[artifaker1]

Jessy,
Well when I look at some of the string nocs on my older bears, my 20 strand 8125 loop is considerably smaller than what was there in dacron. So I kind of wanted to get that loop up to the same size. I was thinking of slipping on a tube of something, but it would have to be just right to work, maybe some of that rubber heat shrink tubing would work. I like the idea of yarn or possibly fly tying floss. I also tried serving it by hand after the loop was done but I didn't like that either with the ribs of hard spectra thread.
Even at 6 strands there is still not going to be that much stretch in the dyneema string, either six or ten strand. About a half of a percent at 10% of the breaking strength (I got that off a rope web site). So there is very little difference in stretch between six and ten strands on bows up to 75lbs or more. But I don't deny your success with what your doing right now with your strings either. The stretch rates that I saw on the rope web site with dacron and nylon included were at 30% of breaking strength; .9 for SK-75 about 3.9 for dacron and 14% for nylon. Sk-75 was actually lower than wire rope. It is real popular for yacht rigging and winch ropes because when it breaks it just falls on the ground with no whiplash (no stretch).
The 10PD20 strand strings I make are for my modern bows, Morrisons, Pronghorns and Black Widows. You know I tried some 6 strand stings and I didn't like the way they shot. I went back and forth between 6 and 10 strand strings on the same bow in the same session and I really like the ten better. Maybe the slightly thicker string can transmit vibration to the cat whiskers better or something like that. And this was on fairly light bows too (36lb widow, 41lb pronghorn, 38lb Morrison longbow). My Morrisons came with a 10 strand 8125 so I just use that on most all of my modern bows. Maybe a twelve on the really heavy stuff.

[Jesse Peltan]

This is interesting.  My 16strand loops are about the same size as 14strands of dacron.  Could you post a picture of the comparison?  The difference you saw between 6 and 10strands was bow tuning.  If you tune the bow specifically for 6 and specifically for 10 you'll probably like 6 better. On bows that light I'd try a 4strand and tune the bow to it to see how you like it.  Thanks for the info on the stretch rates.

[artifaker1]

Well I can't post picks but the 8125 strand is very small. Just look at the size of the string grooves in an older bow. Maybe I got something mixed up, but I still think the major problem is the size of the loops.
You know there was very little performance difference between the six and the ten strand on those above mentioned bows. If anything they shot the same arrow better with the ten in my opinion (especially the Widows). I thought there was more vibration with the smaller string especially on a really long Morrison riser/limb combo. The arrows definitely weren't flagging high left with the smaller string. I came to the conclusion that there is very little difference between them, not enough to use such a small string.
But I still might use the six on older bows, even though if there is any more stretch it would be microscopic.

[artifaker1]

I forgot to add that for the tapering of the padding strands I added another row of nails on the jig. They have to be the exact same distance away from the center of the loop as the main set of nails in the other direction. Now when I have the main strands on the jig I start over with a color I don't like at the first nail and just wind around both groups of nails until I have five or whatever more strands of padding tapered on both ends. The ones for the second loop I just pull out and set aside and put them back in when I get ready to do the second loop. You do have to commit to where you want the center of your loop though with this setup. When you make your cut you have to cut in two places, about 14 inches apart if you start your loops at 7 1/2 that is.
It does work well for a lot of padding, with almost no trouble to add padding to a string.

[FlintRiverKen]

SBD strings can provide 6 strand skinny see below:
------------------
Ken,
We do have a 6 strand string for bows 53# or less.  It is called the SBD Ultra.  Our web site is not quite finished but it is on there now. (http://www.sbdbowstrings.com/index.html)  The Ultra cost is $24 and it makes difference on lighter poundage bows.
Hope this helps.
God bless,    Pierre and Jean-Pierre
SBD Bows Strings >>>------------->
“Crafted for traditional bow hunters"
 www.SBDBowStrings.com
724-323-2107
P.O. Box 193 Dunlevy, Pa.  15432
[email protected]

----- Original Message -----
From: Ken Garcia
To: Pierre Lucas
Sent: Tuesday, January 12, 2010 3:37 PM
Subject: Re:
Hi Pierre,
  could you make a 6 or 4 strand SBD for a 40# bow ? Enjoying the 8 strand SBD I have on a 45# now.  thanks, Ken

[Rob DiStefano]

summa you guys are way braver than me - no way in heck i'd ever put hmpe on an old bow, i'd stick with dacron.

i remember the 70's and those poor folks that tried kevlar strings on their fita bows ... INCOMING! OUCH!

[Jesse Peltan]

Rob, the reason the skinny strings appear so scary is because they aren't the same as the strings most people use.  I've found a skinny 8125 to be safer than dacron because the tips have no more stress but less shock means less stress on the riser, limbs, glue joints, etc.  I've also found the numbers I listed earlier "6 strands of 8125 is good up to a 73# bow. 4 is good up to a 49# bow 3 is good up to a 37# bow" to be the safest strand count.  More puts more stress on the tips. Less puts more stress on the string.  I think that if the old bows had used skinny padded 8125 strings they would have a lot less delaminations, riser cracks, and stress cracks.  A lot of things can appear scary or dangerous at first glance but when you look at the facts can be much safer.

FlintRiverKen, I think they use D-97.  It's a bit different than 8125.  8125 is thinner in diameter and stronger.  8125 also creeps less. D-97 will still work you just won't see all the performance difference I described. 4strands of d-97 wouldn't be enough for a 45# bow but 4strands of 8125 is good up to a 49# bow.

[Jeff Strubberg]

Originally posted by bearbowman:
Those skinny D-97 will shoot on an old bow but padded loops or not you are gonna rattle those old bows apart. The real issue was the glues used back in the day. They were nothing like the glues today.
Sure if you pad the loops really well the tips should be fine but that is not the real issue with the low stretch string. Why do you think Bob Lee fought tooth and nail before they finally went to FF strings? Because the whole world was using them and they had to bite the bullet. 4 or 5 years ago Bob Lee would not warrant a bow that had FF on it.

Actually, making a bow more efficient (like lowering string weight)reduces vibration.  Less moving mass means less oscillating mass, which means less strain on the bow after the arrow has left.

[Jack Whitmire Jr]

Any of you guys who say the low stretch strings are quieter , have any data to back that up. I don't have the best ears but they are way noisier to me.

Not saying it is not true but would like someone to test it with a  instrument used for measuring decibels to prove it once and for all with good unbiased data.

I think I already know the answer but will go with the data.

Jack

[FlintRiverKen]

Jesse great idea about the artificial sinew. Like most folks wanting to learn to make strings the first thing I did was read and re-read all the how-tos and buildalongs. When moving to the hands on stage using a mtl that is inexpensive yet functional is ideal to train with. I have a couple kid's bows needing strings.

I haven't been able to find a buildalong for padded loops on flemish. It would be appreciated if you or Artifaker went into more detail. -thanks Ken

[Rob DiStefano]

Originally posted by Jesse Peltan:
Rob, the reason the skinny strings appear so scary is because they aren't the same as the strings most people use. ....

perhaps you missed my point - it's not the skinny string i have issues with, it's putting hmpe fiber bowstrings (dyneema, spectra, vectran, etc.) on old bows that far more than likely have limbs that can't handle the stress of a low stretch string.

putting a df'97 string on an old bear is just lighting the fuse on a bomb about to explode more sooner than later.

[Rob DiStefano]

Originally posted by Jeff Strubberg:
 

Originally posted by bearbowman:
Those skinny D-97 will shoot on an old bow but padded loops or not you are gonna rattle those old bows apart. The real issue was the glues used back in the day. They were nothing like the glues today.
Sure if you pad the loops really well the tips should be fine but that is not the real issue with the low stretch string. Why do you think Bob Lee fought tooth and nail before they finally went to FF strings? Because the whole world was using them and they had to bite the bullet. 4 or 5 years ago Bob Lee would not warrant a bow that had FF on it.

Actually, making a bow more efficient (like lowering string weight)reduces vibration.  Less moving mass means less oscillating mass, which means less strain on the bow after the arrow has left. [/b]

i don't think vibration, or lack thereof, is the issue - imo, it's the fact that hmpe strings just don't stretch/give anywhere near the stretch factor of dacron.  if the limb tips on any bow can't absorb that shock, they'll blow off.  

i saw that back in the 70's with kevlar low stretch strings - oooo, that was nasty!

[JC]

My bet is, after a couple thousand strings built commercially over the past 30+ years Rob might have a pretty good idea of what's up with how older bows react to newer string materials/designs.

[Terry Green]

What JC just said.

[DCM]

My bet is he suffers from the same superstitions as everybody else, with tons of guys with more and different experience in their ranks as well.

To put it another way, and elk don't know how many legs a horse have.  So, if we make a 4 strand string with essentially the same elasticity as another of different material but say 14 strands.  And the first 4 strand string has a mass of say 70 grains, the 2nd 14 strand 200 grains but we compensate by using heavier arrows with the first, light, 4 strand string,  and we fashion the loops to be the same diameter and shape (perhaps tricky with an endless but certainly possible), does the bow know or care what the string material is?

Not to sound grumpy here, it's not my purpose, but a false argument knows no personalities regardless of how renowned the speaker or subject.  No point in guessing, show me the math, show me the experiment, show me the broken bows (not antecdotes, but properly tested using a control group).  We didn't get to the moon, etc. by guessing how much thrust a rocket engine will make.

[artifaker1]

Flintriverken. Flintriver sounds like my kind of place. I need to get back to being able to post pics so I can show how I modified the jig for string padding. It is probably kind of hard to picture it from just words.
Maybe the hot setup for older bows would be to file off the tip material and glue on a tip of micarta with heat set epoxy. That is all a lot of modern bowyers use for FF.
This subject seems to be all sewed up but there is still the messy detail of a surprising number of people who have come forward and claimed to be using FF on older bows. I'm not at all convinced that a lack of stretch in strings (increases performance) is really bad for the limbs, it might be, but "were" using FF on all these modern bows and many just simply have a layer of tougher material on the tip. That is why I feel that the key is in not having the loops (bigger loops, micarta tips) cut into the string groove and get the whole process of tearing up the limb tips started.
But there ain't no way I'm going to put a six  strand 8125 string on my 73lb Bear/Chastain limbs. Heck I was afraid to shoot them with a 20 strand Dacron string, LOL.

[JC]

Well, DCM, I guess we'll just have to agree to disagree. My personal experience, first hand coincides with Rob's advice: many older bows simply will not stand up to FF material either from tips or limb/glue failure. I found out the hard way on two different bows that previously worked beautifully with B50. I firmly believe the bow DOES care what string material is.

So why would you believe that 4 strands of FF have the same elasticity as 14 strands of B50 (or even FF)? Show me your math, show me the experiment, show me the bows that did not break under experimental conditions.

And as far as the moon analogy, don't assume to tell someone what it takes to get to the moon if they have already been there....

[kybowman]

Wow.  
Now I'm really confused.      

[Terry Green]

What jc just said. Again