Trad Gang

I remember reading in the past about some members doing this..Just wondering if all was still going well.

Still going great on my '59 Grizzly. Not recommending, just reporting.

Still doing great on my longbow. No probs at all, only advantages

Still fine on my Bear red-tip takedown limbs.

Did it to my bbo and it turned it from a bitch to a babe     :archer:

There are bows I would not try it on.  If you have a bow with a laminated micarta or other hard tip overlay - maybe.  Some of the others with no tip overlay on the back - probably a bad idea.  

I have seen bows with the limbs peeled several inches when the FF string split them from the nock grooves toward the riser.  Ouch.

I have and hadn't had any problems! I have seen pics and heard over the years of split limbs, but never witnessed it myself!

When F.F. was first put out in the '80s, folks were trying to use the same strand count as their dacron strings, or less! Without padding!

The original F.F. Spectra, Duponts trade name, was very abrasive, also.

So the padding to cushion the tips, and bowyers using micarta, and such to reinforce them.

Also the trend was lite arrows, superlites, which added to the stress!

dangerous!

Turned my schafer from a ok bow into a super great bow and still working great.   Widow

Agree with Stumpkiller, but it is your bow and do what ya want. I have padded the loops and laid a strip of velcro down the string groove about 2"s from where it ends(beyond) and had old Pearson and Bears hold up fine. Not recommending it just I have done it. To me for the gain in speed it was not really worth it. Shawn

i have a loving family, i have good friends, i don't need to be maimed or dead.  messing with hmpe bowstrings and old glass/wood lam bows is plain nuts.    

:readit:      :saywhat:      :knothead:

Why use Fastflight on a bow not designed for it as Fastflight adds less than ten percent to your speed and is very noisy. Does the added speed , risk of breakage, and noise really help a good shooter at traditional bow ranges, I do not think so.  It is just a crutch and does a good shooter need a crutch, no.

I'm siding with Rob on this one...†

Excuse me, but I didn't see this as an opinion question. The question was directed to people who have tried it.

How's it going?

I don't want to come across as testy here, but I am also interested in results that other members have had and how they did it.

Go ahead and shoot me.

Again, I agree with Blackstick just a question for guys who have tried it. Shawn

Thanks Shawn!

I built a fastflight string (S4) for my Browning Wasp takedown. This bow did not have tip overlays. 3rd shot destroyed the top limb and this was my only try.

James.........................

I don't know if I can put down in words how putting a fastflight string on my shafer improved that bow. I would not keep this bow or shoot it with a b50 string on it no way I hated the way it felt and the performance of that bow. I could not take it any longer so I tried a SBD 8 stran D10 string on it and man you could not believe how much it improved that bow could not believe it was the same bow. It brought the performance up to were most bows in that weight class and made it quiet and vibration free. Just to give you a clue about performance gains that bow went from shooting a 405gr arrow at 167fps to a 505gr arrow at 170fps that is huge.    Widow

Go for it, but when you bust your bow or worse yet yourself over a few FPS don't say you weren't warned. it's my opinion that if someone asked for experience from people who have played russian roulette, I'd warn them not to try it to even though I've never tested it.

Again opinions weren't requested, I have FF strings on a couple non FF bows and have had no Ill effects, infact one bow is a 60#er it has improved the shootability of the bow in my opinion. The hand shock has greatly diminshed and vibrations way down.

i cannot comment, as i have not tried it myself , but i did ask the same question couple of days ago (ANYONE USE FF STRINGS ON NON FF BOW'S)?  and i got crucified with comments like  HELP ME HERE- WHY WOULD YOU EVEN ASK THIS QUESTION.  from rob ,and others .So i am glad of this thread being revived, it answers my curiosity on this subject.i am pleased to know that i am not that STUPID for asking the question , as i was made to feel. THANKS to ALL THE GREAT PEOPLE THAT TRY TO HELP YOU TO UNDERSTAND when you dont know something!!!!

QuoteExcuse me, but I didn't see this as an opinion question.  

the answer that you didn't want to hear was not an opinion but the safety concern and not wanting anyone to get injured....†

I do have a hairline crack on a bob lee signature that I tried using d97 on.  I am not sure if it string related or not.  It is around the limb bolts on the underside.   I am pretty careful about not overtightening things so I know thats not it.  The only other thing I can think of is the string.....who knows.

QuoteOriginally posted by Blackstick:
Excuse me, but I didn't see this as an opinion question. The question was directed to people who have tried it.

How's it going?

I don't want to come across as testy here, but I am also interested in results that other members have had and how they did it.

Go ahead and shoot me.

ABSOLUTELY!!!

I know of a feller that padded the loops on an old Shakespeare.. been shooting that thing for a couple years with no problems. like has been said before not promoting, just reporting!

Jason

We provide high performance non stretch strings with every bow we ship.  That includes selfbows.

Yes we reenforce the tips overlays to prevent cut through by the material.

These strings are faster and quieter on all bows but if the bow is not designed for it you risk ruining the bow.

That's your call I guess.

Mike

QuoteOriginally posted by Blackstick:
Excuse me, but I didn't see this as an opinion question. The question was directed to people who have tried it.

How's it going?

I don't want to come across as testy here, but I am also interested in results that other members have had and how they did it.

Go ahead and shoot me.

with questions such as yours, there is always the possibility that such actions - using old wood/glass laminated bows with hmpe string fiber - is acceptable.  it's not.  in fact, it's plain outright stupid.  someone had to say it or else your simple question might be construed as something that some clueless person should try since someone somewhere is actually doing it.

let me see how clear i can make this, in order to hopefully prevent bows from blowing up (I HAVE WITNESSED THIS MORE THAN ONCE, it's not a pretty sight!), or folks getting seriously hurt or killed ....

 (http://www.tradgang.com/docs/caution.jpg)

this does NOT include self bows!  they are, for the most part, given dispensation and are, for the most part, safe to use hmpe bowstrings.

you wanna use hmpe on old bows?  feeling lucky?

Rob, your funny!! You just don't get it do ya? Shawn

QuoteOriginally posted by Shawn Leonard:
Rob, your funny!! You just don't get it do ya? Shawn

don't i? - you have a pm .....

after a pm conversation with mike (wingnut) i've reopened this thread.

let me tell ya'll why i'm dead set against mixing hmpe and old wood/glass bows that aren't built to handle such ultra high tensile strength fiber.  

i don't wanna see good folk get hurt or worse.

i've witnessed two old bows blow, used by other archers, that were loaded with hmpe strings. one top limb tip flipped 20 yards and into the excelsior bales used for the indoor range butts. one guy was next to me on the shooting line, to my right, when the limb nearly sheared in half with a huge BANG!

i have also been on the same shooting line with archers in the early 70's using kevlar strings on their hoyt and golden eagle target recurves, and in more than a few instances those strings resulted in fragmented limbs.  have you ever been present when a bow limb shrapnels?  it will scare the living beejeesus outta you, i promise.  don't let that happen to you, be wise, be safe, not sorry.

so, IF you have been using hmpe on yer old bow, think of this as a ticking time bomb.  and if ya don't believe me, fine, not gonna be my problem or trad gang's problem cause very clearly we're both saying ...

(http://www.tradgang.com/docs/caution.jpg)

Thanks Rob, I think this will help people make an informed decision. Good or bad, it actually may prevent people from trying this. I agree I would hate to see anyone get hurt doing anything archery related! Shawn

Thanks Rob for reopenning this thread.

I asked this question on another forum this morning looking for myth buster or bow buster information.

In a matter of minutes I had 10 broken bows attributed to use of FF.

A bit of info provided that made a lot of sense was that bow like us get brittle with age.  Old laminations, fiberglass, overlays and glues breakdown over time.  This being said there are bows out there that will shoot for the rest of our lives.  But some have been effected.  

No one will argue that the new strings put more stress on the bow and if yours is one of the ones on the downside of life, well that stress will probably tip it over the edge.

So there is no reason to endanger a piece of history for a couple of fps not to mention an eye or worse.

I'll agree now with Rob and say it's not worth it.

Mike

QuoteOriginally posted by Rob DiStefano:
i have a loving family, i have good friends, i don't need to be maimed or dead.  messing with hmpe bowstrings and old glass/wood lam bows is plain nuts.    

:readit:      :saywhat:      :knothead:

Ditto...

QuoteNo one will argue that the new strings put more stress on the bow...  

I won't argue it, but I will question it.  I have yet to see any evidence of this, or a viable explanation as to why.

My thoughts are along these lines.  

It's a known fact that HMPE strings greatly reduce hand shock, especially in bows that have noticeable hand shock.

What is hand shock?  It's wasted energy resonating down the limbs to the riser and into the shooter's hand.  If you have a string that reduces this wasted energy (evidently by imparting it into the arrow), how can that be "harder" on the bow?  I may be looking at this all wrong, but it would seem to me that a string that increases hand shock would be increasing the wear and tear on the bow.

I've broken several bows over the years, and personally know folks that have broken bows.  I don't know of even one where the failure could be contributed to the string--almost all of them had dacron strings on them to begin with.

The only damage I've seen done by a "Fast Flight" string was, as mentioned, a tiny (non-padded loop) string on an old bow that didn't have the string grooves cut at the proper angle, using the old (and very abrasive) "Fast Flight" material.  I've seen this twice, in totally unrelated cases.

It seems that when a bow fails, if it has a "Fast Flight" string on it, the string automatically gets the blame.  If it has a dacron string on it, something else gets the blame.

I can't say that it is safe to shoot a "Fast Flight" string on a "non-Fast Flight" bow, but I've yet to experience anything that says you can't do it safely, as long as the string is properly made.

I have to go on my own experiences, because on the w.w.w. I've seen everything from flemish strings being blamed for twisted limbs to warranties voided over using a dacron string, and pretty much everything in-between.

I'm still looking for answers to this one--solid answers.  I am NOT a proponent of really tiny strings--IMO they aren't nearly as safe as a moderate strand count--so I've got no agenda here, other than just trying to learn more.

So......FWIW, in my opinion the jury is still out on this one.  

Oh yeah...I don't recommend doing it--I much rather be safe than sorry.  I am a big proponent of using HMPE materials on bows rated for it, for the many benefits it offers.

chad,

imho high tensile hmpe strings, by and of themselves, do not inhibit "hand shock".  i've proved that to myself with my own tests. there are other issues involved, some i understand and some i still don't.  but ....

more importantly, whether it does that or not has absolutely nothing to do with the matter at hand - hmpe strings used on old bows.  i've had first hand experience in that matter and i know that the two components are bad mojo.  

if you are sceptical and a "show me to believe" kinda person, and refuse to have the faith that i and others have seen what hmpe can do to old bows, well, certainly your call.  

but let's be clear about this so that your statements will carry no weight to the clueless of the trad archery world,  as some poor fools will interpret your scepticism as good enuf to use hmpe and old bows.  best of luck of luck to those that use the two together, 'cause man you are gonna need it.  remember what you read here at trad gang in this thread, 'cause i promise not to holler "i told you so!".

On the hand shock...my bow arm elbow is very sensitive to shock.  I own a couple of bows that I will not shoot with dacron strings, due to the hand shock--repetitive shooting with them tears up my elbow.  I've won the "Howard Hill"--TWICE--with one of them, and I won the TN Classic "Selfbow Challenge" with the other--after putting Dynaflight strings on them.  Not exactly scientific, but my elbow won't lie to me.  Dunno what else it could have been, because the string is all I changed, and I made the strings.  I've had countless reports of folks telling me they had the same experience.  Based on that, it steers me into thinking...does it not stand to reason that less shock should equal less wear and tear on the bow?  I can't say it does or doesn't--I'm asking, not telling.

I can't honestly say whether HMPE materials are "hard" on old bows or not, as I have no solid proof either way.  I have limited experience and lots of opinions, most of which sway one way, but no proof to verify it.  

I've searched for this proof for years, just like I've looked for evidence to back claims that HMPE materials will shorten the life of any bow, that they are inherently noisier, etc.  I get lots of opinion, but nothing I can verify.  

I thought I was pretty clear on where I stand with old bows and HMPE strings.  The last statement of my previous post:

 

QuoteOh yeah...I don't recommend doing it--I much rather be safe than sorry. I am a big proponent of using HMPE materials  on bows rated for it , for the many benefits it offers.

A question,  Do the number of twists in a padded fast flight or other new string have an effect of beating up a bow less than say a padded string without as many twists needed to get it to the proper length?  I have seen a case where a fastflight was channeling into a bamboo longbow a bit, but I think that was more of a hard material and lack of wax issue.

Chad,

I know you sell strings but to provide encouragement to the folks wanting to do this is just not good business.  Heck sell them B50 stings for the old bows.  The worst bow for hand shock I ever shot was the traveling bear bow.  I won't have dreamed at putting a high performancs string on it to calm it down if it had a 10% chance of shortening it's life.  Some bows have a lot of handshock. .  .period.

We have sited 12 cases where these strings were used on older bows that self destructed in a few shots.  Some quite spectacularly. I guess that doesn't provide enough data to make an informed decision for some folks but for me it just doesn't make sense to risk the bows life or someone elses.

Mike

I'm kinda with Wingnut on this one. Why beat a old horse to dead again. If there's a chance that FF type string could damage your bow even a small chance don't do it. get another bow that is recommended for fast flight type strings. The gain is just not big enough,on older bows.

Well said Chad ... Oh Yeah, Love Your Strings !!!

QuoteI know you sell strings but to provide encouragement to the folks wanting to do this is just not good business.

Neither is crediting me with things I never said or implied.  Once again, from my original (and completely unaltered) post:

"Oh yeah...I don't recommend doing it--I much rather be safe than sorry."

I personally know of at least two (glass, laminated) bows that self-destructed the first time they were drawn back.  I have first-hand knowledge of a bunch more that "blew up" and they had never had anything other than a dacron string on them.

I'm not posting to sell strings--I'm staying plenty busy, thanks.  I'm posting to see if there is any verifiable proof to back the opinions.  I like to get to the bottom of things.  If I didn't, then I'd believe that dacron strings caused bows to fail and flemish strings caused twisted limbs.

Need more proof?  Do a search on my posts.  I won't even go as far as recommending or using "skinny" HMPE strings (as noted in the title of the thread) on bows made to accept HMPE materials, much less on bows not made for them.


Once again, is it worth the risk?  Not to me.  I only have 2 non-FF bows in my stable, and one of those hasn't been shot since I got it--and likely never will be.  The other will never have anything other than a dacron string on it.  Want to guess why?

Now why would I be "pushing" something I won't use myself?  Simple answer, I won't.  That's not the way I do business.  Never have, never will.

I never thought that just asking for some simple facts would stir up a ruckus.  I'm done with it.

Like Chad said...............the strings get the blame. Personally I have had 5 bows break over the years: 3 old bows with B 50 strings and 2 new bows rated for HMPE with 12 strand D97 strings.

I conviced Rob to reopen this thread because I though that real world experience would come forward to give the new guys some guidance.

So I ask: Joe new Guy buys a Kodiak magnum at his local pawn shop.  No string so he goes too the archery shop and the kid behind the counter figures what length string he needs and asks FF or Dacron? The guy goes whats the diff?  The kid says FF is faster so he buys it.

Are you going to tell him here that it's ok to shoot it or to go back and get the dacron string?

That's my final post on this thread.

Mike

There goes Rob talking about those hemp strings again.  :cool:  

Geez, Bjorn, how do you release without flinching? I've had one bow break and it still kinda freaks me out. If it had happened 5 times, I'd have some sort of psychologic disorder...other than the one(s) I already have!  :D

i reopened the thread, so c'mon guys, tell me your good (or bad) experiences with hmpe and old bows.  don't be shy, if yer using that stuff with yer old bow, let us know so we can steer clear of you on the shooting line.  

but do show us why you think it's ok, why it's a safe enough for you.

i'll tell ya where it's got me - i see a guy with an old bear or howatt or hoyt or whatever and i'll go outta my way to ask about the bowstring he's using and if i hear "fastflight" i stay far away from him when he's pulling that string.

as they say, ymmv.

The effects can only been modeled in a dynamic Hydrocode software. This software is usually run by people in the automotive industry who do crash tests or other vibration induced design.
What would be real interesting is the failure mode of the failed bows, which was blamed on the low stretch string.
One failure mode was the "cutting" along the string groove into the limbs and splitting them.
This was clearly induced by less string area on less string groove bow material area resulting in higher pressures beeing induced locally into the bow. This led to cutting and grinding because of the abrasive nature of the material. By padding the loop, the traditional contact area size can be reinstated, preventing the described failure mode.
The effect of the lower stretch must be simulated in a hydrocode to investigate potential failure modes modeling the fiberglas,the gluelines and the wood. Especially important is the used glue type in the bows.
Epoxy does not equal epoxy. So there may be timeline when certain glue compositions where discontinued and others added. These glue compositions will influence the dynamic behavior of the sandwich profile. And not to forget: bow glass is already a composite system by itself, beeing influenced by the glasfiber and the glue matrix....

I just don't know enough about strings to enter in on this discussion but would like to learn. All the letter and number terminology has confused me the last few years(easier to do nowadays). I have a modern longbow(Northern Mist), a relatively older glass longbow may be 20 years old or so(Massie), and a wood composite, Ipe and elm(Newwwood). Where should I go to inform myself at my options or I'd take suggestions unless this is hijacking the thread then please excuse me.

QuoteOriginally posted by tecum-tha:
The effects can only been modeled in a dynamic Hydrocode software. This software is usually run by people in the automotive industry who do crash tests or other vibration induced design.
What would be real interesting is the failure mode of the failed bows, which was blamed on the low stretch string.
One failure mode was the "cutting" along the string groove into the limbs and splitting them.
This was clearly induced by less string area on less string groove bow material area resulting in higher pressures beeing induced locally into the bow. This led to cutting and grinding because of the abrasive nature of the material. By padding the loop, the traditional contact area size can be reinstated, preventing the described failure mode.
The effect of the lower stretch must be simulated in a hydrocode to investigate potential failure modes modeling the fiberglas,the gluelines and the wood. Especially important is the used glue type in the bows.
Epoxy does not equal epoxy. So there may be timeline when certain glue compositions where discontinued and others added. These glue compositions will influence the dynamic behavior of the sandwich profile. And not to forget: bow glass is already a composite system by itself, beeing influenced by the glasfiber and the glue matrix....

all well and good ONLY if someone steps up to the plate and does the proper testing, whatever that may be.  

until then, the reports of blown bows should be cause enuf to think twice about combining hmpe and old wood/glass bows.

QuoteOriginally posted by smoke1953:
I just don't know enough about strings to enter in on this discussion but would like to learn. All the letter and number terminology has confused me the last few years(easier to do nowadays). I have a modern longbow(Northern Mist), a relatively older glass longbow may be 20 years old or so(Massie), and a wood composite, Ipe and elm(Newwwood). Where should I go to inform myself at my options or I'd take suggestions unless this is hijacking the thread then please excuse me.

if you're unsure, and if at all possible, go back to the source (bowyer) and ask.  if that's not possible, and i were you, i'd stick with a dacron bowstring.

But as Chad said, all these blown bows, were they gonna blow regardles of string material. I have seen a several bows blow up over the years and at least 3 of them were older bows using B-50 or a linen string. I also have seen a couple blow that were overlaid and set-up to shoot FF and they blew up too, ask Curt(Guru) about his bow that blew. It was of very modern design and he was shooting FF. Again I have to say if you pad the loops and di everything possible to prevent the string from cutting into the limb, add wool or moleskin or velcro in the string grooves and you want to attempt it, that is up to the person. Just use a thread like this to make an informed decision and listen to whatever makes ya feel safe. Shawn

Spot-on Shawn.  Bows break.  Anyone with any amount of "real world experience" knows this.  

To completely avoid the risk of having one break on you, the only 100% "safe" thing to do is never draw back a bow.  After that, avoid old bows and self bows, since they have the highest failure rate (regardless of the string used).  Then find out which bowyers have ever had a bow fail and avoid all of those.  Ooops....right back to step one, because anyone who's made any number of bows has had a failure.

What I'd like to do is find out if the string actually caused the failure, and why.  If we could pin that down, then we could possibly modify a string to avoid this.  

I don't have the means, equipment, or brains for such a test, but I'd sure be interested in the results if anyone were to do it.

Until then, I will continue to recommend (as I ALWAYS have) to stick with dacron on older bows.  As I've ALWAYS said on this topic, better safe than sorry.

However, until I see actual, verifiable proof, I cannot honestly say that I know a "FF" type string is detrimental to old bows.  I can just say that, in my opinion, it's not something I would do.  Too many great bows on the market to worry about what string I can use on a select few.

almost all new stick bows (within the last 10 to 15 years or so, at the very least) are built to handle modern hmpe (High Modulous PolyEthylene) bowstring fiber.  hmpe is at least twice as strong (in terms of tensile strength), if not 3x as strong, as a comparable diameter strand of dacron (polyester) fiber.  i don't know what the precise measured difference of elasticity is between known diameters of hmpe and polyester, but it is significant.  12 strands of hmpe will have a tensile strength of at least 1200#, while 12 strands of polyester will have at best 600#.  but, and more importantly, hmpe will have far far less stretch than dacron.

"old bow" means a glass/wood composite bow that was built, for the most part, somewhere between the late 1940's and perhaps on to the late 1980's and early 1990's.  the type of fiberglass and resin epoxies used in those old bows, coupled with limb tips that have little or no substantial physical enhancing, were meant to be used with the best bowstring fiber available at those times - dacron (polyester).  

if you are unsure if a stick bow was built to handle hmpe bowstring fiber, and the bowyer/company is unavailable, you will be at a safety risk by using an hmpe bowstring.  why?  because people have witnessed these bows self destruct when used with hmpe bowstrings.  hearsay?  yes.  fact?  none documented on video that i know of.  

can anyone prove that hmpe is capable of blowing an old stick bow's limb(s)? no ... not unless it is tested using a shooting machine ... and even then, it may not blow immediately and may not blow for a thousand firings.  why?  i don't know.  it may have to do with bow design, the current state of the bow's materials, and other factors.

how could an hmpe string cause a perfectly good old bear bow in pristine condition to delam a limb tip?  these are some of the involved parameters - the condition and the materials used in the stick bow, the build and materials specific to the bow's limb tips, the diameter of the hmpe string loops, the weight of the arrow in regards to the bow's holding weight, the method of release.  

hmpe stretches very little as compared to polyester.  after release, as the bow attempts to return to brace height, the transmission (bowstring) delivers the stored limb energy to the vehicle (arrow).  if the arrow is too light, or if by other means it does not accept the transmitted energy, that energy is redirected via the transmission back to limbs - first at the tips - then to the riser.  high speed/slow motion videos show that in great detail.          

since there is much less elasticity with hmpe bowstrings, as the limbs return to brace height the abrupt stopping of the limbs terminates all the residual force to the bow's limb tips.  

my theory is that with dacron there is a fair amount of stretch and that allows the unused limb energy to flow back to the limbs, down to the riser and (perhaps) to the shooter's bow hand ... whereas with hmpe, it stops dead at the limb tips (because the non-elastic string will not allow the tips to significantly move forward) and the unused limb energy goes back into the string (ever notice the higher pitch that hmpe strings give on release?).  the pivot points for all this energy movement are the bow's limb tips.  they are the nodes that take the brunt of the released limb/string force.  they need to be significantly built up/beefed up for that task.

Well, I'm prepared to do some testing on this to put it to bed, once and for all.

If a bowyer, any bowyer, would be prepared to send me 2 identical, unused bows, NOT rated for HMPE strings, I will fit one with a B50 string & one with an HMPE string with padded loops & shoot identical arrows from each one.
I'll take one shot with each bow, continuously until either one of the bows gives out, or until I get sick of testing (say 100 arrows a day with each bow for 3 months)

Once I've done this I will return both bows to the bowyer.

If the HMPE strung bow survives the test, I'd call it fairly conclusive. If it dies, I'd also call it fairly conclusive.

How'd that be?

I don't have two identical bows, but I do have a bear recurve I'd dedicate to that kind of testing.

Rob D, I salute your caution.  I don't think anyone should be encouraged to make this kind of change without some serious testing on that particular bow platform.  Having said that, you have to throw out every one of the breaks you've see occur with kevlar.  You know that stuff was notorious both for cutting into bow limbs reinforced or not and for breaking under the string servings whenever the heck it felt like it.

QuoteOriginally posted by Jeff Strubberg:
....  Having said that, you have to throw out every one of the breaks you've see occur with kevlar.  You know that stuff was notorious both for cutting into bow limbs reinforced or not and for breaking under the string servings whenever the heck it felt like it.

right, kevlar bowstrings (if you could even find any today, and i hope no one can) have nothing to directly do with this topic.  my prior posted references to kevlar were strictly for the effect of a blown bow and nothing more.

Rob, you're helping my learning curve even if some may be theory.

Robtattoo, I believe you may have to take other steps too, like wrap the string ends in biwhush or heavy wool yard, velcro in the string groove, as to proper steps to be taken I have no clue but agree with Chad as I stated earlier. Use at you and your bows own risk and know the possibility exist that a bow may expode. Look at Bob Lees older bows I am talking from 15 years ago, they were not rated for FF but man I shot a bunch of those bows with every kind of string there is and never had a problem. Same with a Schaffer I owned for a couple years. I will say if you are gonna try FF on a bow, know the risks and try to minimize them the best ya can if ya can for safties sake. Shawn

Chad is spot on with saying there is no such thing as hard evidence the bowstring material was the culprit, why the bow failed.
In my post I described one known and evident failure mode of a bow using a very thin and highly abrasive string material.
Result: We should pad our loops to adequate strand counts to resemble the same diameter string than once before. Hemp string material is much less stretchy than dacron, but since its tensile strength was less than dacron, a thicker string was used spreading the forces out into a bigger local area at the bow nocks.
In soft yew wood english longbows, horn nocks where used, because of horns ability to withstand higher pressures and probably failures by splitting limbs from down the nocks.

Bow profiles: Obviously a multitude of risers failed over time, because they were cut to center or even past center. The bowyers did not think about a bow mechanically, but in matters of balance, beauty and mostly arrow clearance.
This can lead to additional forces in the riser cross section not accounted for by the bowyer. Reason: the shear center of the cross section  is no longer close enough to the centroid, inducing torsion strain additional to the bending stress.
Nice little graphical description:
http://www.mcadcentral.com/proe/forum/forum_posts.asp?TID=38317

thread of bimbo666

Most bowyers are not engineers and do not calculate their bow designs. Even if one calculates a bow design, it is usually not done using dynamic hydrocode modeling. Way to expensive. The software alone is $15000 per year and you need a specially trained operator who knows what he does.

Old bow risers: A lot of old bow from the late 50ies to the late 60ies were using a very field bow like sight window. Long and slender and prone to torsional problems. But most bows during this time were of low to moderate weight, mostly probably in the 40-45# area. The heavier a bow gets, the more will the riser area get stressed. If you get higher in draw weight without reinforcing your riser, it will sooner or later break.
This is especially true for wooden risers, because wood is an inhomogenious (natural) material.
There is a reason why modern risers are made from metal, thin laminated and/or pressure-resin impregnated woods. The material is made more homogenious and thus is less prone to local failure.

For all the people who had failures:
Could you describe the failure mode of the bow, that failed? Especially the modern low stretch rated bows? But also older bows which failed no matter what the string material was?

Sounds like we are getting somewhere.

Just to be clear, I have no doubt there havs been old bows delam with HMPE strings.  My point is there's been a ton of old bows delam with dacron strings--I've got first-hand experience with this.  I have a brand-new bow in my shop (not one I sold, or even bought) that de-lamed the first time it was drawn to anchor.

What caused the failures?  As I said before, a FF type string has always been the scapegoat if that was the string on the bow.  If not, then it's "something else".  I've yet to see any proof of this, and being a string nut, this bothers me.  It wasn't that many years ago that several folks were proclaiming that FF strings would shorten the life of any bow.

The lack of stretch/creep may be a factor, BUT....there's at least one "primitive" string material that is similar to the HMPE materials for lack of stretch/creep.  Off the top of my head I can't remember which one it is....silk, I think?  Anyhow, I've never heard it blamed for breaking bows.

Erring to the side of caution is a good idea, IMO.  I won't recommend tiny strings for that reason--I've had too many reports of disasters due to them, but I won't berate someone for liking them.

I like the test ideas and volunteers, but if I had a choice I'd take it further.  If a particular string shortens the life of one bow, will it shorten the life of the rest?  Reason says it should.  If it will shorten the life of a bow, how much and why?  Is there anything that can be done to fix the problem?

I'm just a stickler for details, at least on this subject.  Seeing/hearing tons of erroneous statements over the years has made me a bit of a skeptic.

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.

Seems like linen is very low stretch, but it's also very large as far as fibers go, and linen strings are usually of a huge diameter.

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.

QuoteOriginally 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.

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?

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.

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.

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