fast flight on vintage bows

[bswear]

What is the real reason we can't shoot fast flite on vintage bows?  Wear in the tips?  This could be remedied by padding the loops.  I just can't really see what prevents it other than everyone says don't do it.

[4runr]

What's the purpose for using it?

[d. ward]

bows built before 1960's or so had paper tip overlays and FF's cut through the paper overlays.After 1960 most manufactures switched over to fiberglass tip overlays.However there was no testing data back in the 50's and 60's and into the 1970's because there were no FF strings to test with.Most bows manufactured in the 1970's will stand up to the FF strings.

[d. ward]

You know if ya gotta do it you know you just gotta try that FF on your old bow.Before you do use the no stretch FF type material.Try this I shoot a 10-12 stand string with padded loops and serving on a 55# bow.That 12 stand B-50 dacron is as fast as a FF string on my 1964 Kodiak.The dacron makes less noise and the bow is about the same speed may 1-2 ft per second faster with the FF then the 12 stand.However the FF makes to much noise.
In 1964 there were no FF strings to test the bows with.So we are not sure the fade outs will take the schock of the FF string.I will say this since the onslot (from the mid 1980's) of FF strings on other bows I've made lots of money repairing old bow tip overlays.But please try the 10-12 stand dacron first.bd

[d. ward]

food for thought....bd  

[TonyW]

"The candle that burns the brightest burns twice as fast"

I see all the stress cracks on bows as old as mine and wonder if:

Dry fires?
Loose nocks?
Light arrows?
Minimum strands on strings?
 
Decades of this abuse + fast flight =  CRACK!

So I use heavy arrows, max strands of Dacron string, and snug nocks. How can we know how much stress happened to our bows before we got 'em?

I can't see a real difference in fps, but I do notice zero stress lines per limb!

[bswear]

So the problem is the string eats the tips, not limbs snapping off at the fadeouts?  Lots of people asking me why...I don't plan to do it but just wondering what the failure is.  I might try an 8 strand b-50, though.  FYI, I put an 8-strand d-97 on my 55# widow and it shoots faster and quieter than the standard 14 strand Widow string. Got me thinking about all our "known" knowledge that is sorta based on traditional logic, not fact.

[bswear]

Oh forgot to add, my arrow weigh 676 grains, so the bow is not exactly going be dry fired.

[bswear]

Doc,

That 55# '62 K of mine in your shop might be a good candidate for a skinny string.  Think 8 strands is too light?

[d. ward]

8 stand would work sweet but do pad the loops and as mentioned keep and eye on your nocs.
I often wonderd if old bows would handle the no stretch of FF type strings and I do know several guy's who do use FF and have for a few years with no problemo's at all ??? bd

[Grant Young]

I know nothing compared to 'Doc and Rich but I wouldn't use FF on any bow I didn't consider very replaceable. Energy has to go somewhere and a deadstop doesn't give it much time to dissipate. I do use light dacron strings, however- 12-13 strand endless loop on 65-70# bows. I try to keep them in good repair, and replace them fairly regularly. I shoot too much to risk the damage. Doc's right, sometimes bows can take a lot and keep working, three years ago I dropped my styleI out of a tree at around 12-15 feet down a rocky hillside to boot. No problems. I don't intend to do it again, though. GY

[Jeremy]

I have a '58 Polar with nearly every problem with the glass imaginable so I figured "he**, why not" and put a low-stretch string on it (with padded loops).  The first thing I noticed was the lack of any limb vibration after the shot and the brace height sweet spot was lower.  Much nicer to shoot than with my standard 12 strand B50.  Going on one year now and I think it's earned a refinish and proper tip overlays.

On every bow I've owned (and tried it) the limbs vibrated less with the low-stretch strings than with dacron, so I have a hard time believing there's any extra stress on the limbs.  Limb tips on the other hand... most old bows (and new bows for that matter) don't have tips that are shaped very well, concentrating stress at the worst possible place.  Add relatively skinny strings to the mix and you've got a recipe for disaster.  Pad the loops and shape the tip overlays properly and...

[bswear]

Interesting!  Thanks for sharing.

[artifaker1]

If one wanted to investigate this FF thing with bows that are not too dear, then the hot setup right now is a skinny 8125 with copiously padded loops. A ten strand will give you the skinny effect and still leave some room for problems on a hunt. The strands are smaller than D97 and near as strong, over 100lbs.
What people are seeing with the skinny FF string is a large reduction of noise and vibration and some surprising pickups in the horse power department. And there are people that are using these skinny strings on older bows successfully. This probably should be investigated more scientifically. I'm going to try it sometime soon but I think it has to be the skinny string, and I wouldn't even try a 14 or 16 strand brownells or D97. Those are just way stronger than they need to be and that might be why they are so noisy and tear up old limb tips. D97 is 130lbs a strand. Right now some people are using a 8 strand D97 for a skinny string which works ok. I think the 8125 is better, it creeps less and is even skinnier.
With dacron, I had better performance out of my 70lb bear take down limbs with a 20 strand string then a 14 or 16 strand. I think that the dacron is too stretchy to use like a skinny FF string. If you go too low in the strands they stretch on release taking some of the heat off the arrow, like shooting with rubber bands. I checked the above limbs at 45 yards with a 995 grain arrow and I'm sure it put the arrows higher on the target with the twenty strand string. Those limbs just shredded at least two 14 or 16 strand strings before I put the 20 on. Now you can shoot it a couple hundred times without re-bracing it too.

[Bjorn]

I have been shooting a 1959 Grizzly using a 4 strand D97 string with loops padded to 16 strands. The bow is only 35# so the 4 strand string is perfect, and has really livened up the bow. The string has been on the bow for 8 months-the bow stays strung and I try to shoot it every coupla' days. No intention of trying this on a fav Kodiak any time soon.

[Jeremy]

The other thing that's worth mentioning (again) is the newer strings are low-stretch, not NO-stretch.  When you have the 18 strand FF-type string most places sell that's a cable that's not going to stretch much on the shot.  Now a 6-12 strand is going to stretch much more.

One of the TBB gives some #'s for stretching.  After the string has settled in dacron will stretch ~4%, "FF" 2%, linen 3% and silk ~6% (or something close to those #'s... my TBBs got moved to my shop and are in a box).  I know a linen string feels more like FF than B50.

[artifaker1]

Jeremy, do you think that stretch percent rate is constant, or would it be variable according to how stressed the string is? And would it be less variable with anti-stretch materials like 8125?
When I first saw the skinny string posts, my first instinctive reaction was that they were introducing more stretch in the string, quieting down the bows. But I'm pretty sure that it is the lack of stretch that really gives ff material the performance advantage, which can be quite a bit when the skinny string concept is used. So if that is true then the FF strings still might not stretch a whole lot.

[Jeremy]

Some ramblings...

I don't see where 8125 stretches any less than D97, TS1 or Ultracam.  It has less creep than some of the others, but not less stretch - at least that's what my forearm is telling me LOL!

If you increase the number of strands in a string, it's going to stretch less.  I don't know if those % numbers were figured out for whole strings, sinlge plys or what.  They do seem to be in the ballpark though (again, going by my highly calibrated forearm   )  I've tried the ultra skinny strings and they'll hit my arm just like a dacron string, so they definitely do stretch.

If the lack of stretch was the main contributor, than the thicker low-stretch strings would perform better.  That's not the case though.  The skinny strings (with less mass) perform better.  Make a real skinny dacron string and you'll increase the speed as well (and the amount it'll stretch)

[d. ward]

oh yeah 8 stand dacron on a 55# bow does not have the same life span as a 16-18.The 16-18 on my T/D is like 3 years old.The 3 bundle 6 strand Larry made me for my 1964 stretched alot like I mean alot. bd

[artifaker1]

Jeremy, I decided to go out and look at the advanced fiber world. I turns out that DSM invented Dyneema SK60 and SK75 (a UHMPE fiber). BCY makes D97, 8125, 450+ and 452 and they are comprised mainly of SK75. The latter two are combined with a fiber called Vectran from the Kevlar family (Aremid).
Brownells used to use Spectra from Honeywell in there fast flight which is a UHMPE fiber too. BCY uses Spectra in serving thread as it is more suitable to braiding. Brownells has just stopped using Spectra and switched to SK75 and basically come out with several new products that are near copies of BCY strands.
I was able to find some data on SK75 at Samson rope company's web site. They posted the following stretch data; After previous stabilization, and after 50 cycles of stretch at 10% breaking strength it has .46% of stretch per length. At 20% it is .7% and at 30% breaking strength it is up to .96%. This basicly represents "no stretch".
With a skinny string, we are using SK75 probably around 20%. That means, I think, that a 60 inch string stretches 42/100s of an inch at full draw. There might be a spike at release but it wouldn't be to high if there even was one.
Now we need to get stretch data on B500 Dacron. I think we'll find with it, to get to that level of anti-stretch, we will have to go up in strands, a lot.
Remember the purpose of this post is to quantify what is safe to use on older bows for string material.