What makes a bow fast flight safe?

[sffar]

Is it the adhesives used? Sturdier build? I've read some debates about whether it means anything at all, but if a bowyer certifies his bow is FF safe, what's been done to insure it?
Thanks,
Sam

[marty z]

The tips

[sffar]

Thanks, Marty.
I've seen thin, beefy, wood, micarta . . many styles of tips that are OK for FF, so what's the difference? Just the tips are different?

[Swissbow]

I have seen guys shooting selfbows without any reinforcement on the tips with FF strings for a long time without any problems. IMHO if the bow is well built and your arrows are not to light then you can shoot it with FF.

----------
Andy

[sffar]

Andy,
Something must make a bowyer comfortable with recommending FF. Padded loops are made to keep thin string from cutting wood limb tips. Heavier arrows absorb lots of energy. There must be a little more shock to the bow than with Dacron after the arrow leaves, but as you say, many find it doesn't matter. So what gets done that's different than before making bows for FF string?

[Swissbow]

I can only speak for myself and there is nothing i do deliberately to make the bow FF proof. Ok i admit, i only build glass bows and i use phenol for the tips. But i think this is more to protect the string from getting ripped apart by the glass. And i agree with you i would not recommend to use an endless string without padded loops on a wooden selfbow. But besides that...

----------
Andy

[sffar]

I've seen bows with horn on the tips–not like the English longbows have–that have FF string, too. Also just wood.bamboo laminate all the way to pretty slim tips. The usual worry is that the limbs split from the tips, from what I understand, if they're not built for the less stretchy material.

[DCM]

"Something must make a bowyer comfortable with recommending FF."

I can only speak for myself, but the answer would be experience in my case.  I tried it early on and never looked back.  I've used it on selfbows of woods as soft as yew, elm, hackberry.  I make flemish strings, at least 14 strands of FF (diameter varies with the brand of material) in the loops.  I rarely if ever shoot arrows weighing less than 8 grains per pound of draw weight.  Never had a single problem of any kind with FF.  

On the 3 glass bows I've made, and 1/2 dozen I've re-tillered and re-fit the overlays and string grooves, never had a problem.  I build up glass lam bows with an extra layer of glass usually, and whatever thickness of wood required for aesthetics.  I think stack height makes some difference, for example a bow with a great deal of thickness taper would necessarily have a relatively thin outer limb at the string grooves.  I'd guess I build up to at least 5/16" thickness or more.

I think the shape and size of the string groove matters a great deal.  A teardrop shape sufficiently generous in size and angled such that the forces are directed as much perpendicular to the back / belly (green arrow) of the bow as possible helps mitigate the tendancy for the string grooves to split out along the lenght of the limb on the belly (red arrow).  This is the only pic I have, and overly generous in size than my typical.

You just need plenty of surface area to take the load, and a shape that exploits the strenght of wood (fiberglass) in compression, versus shear.

 

[sffar]

Thanks, DCM. The photos help a lot. I appreciate your response (and all the responses). I'm pretty new to the sport, and am trying to make sense of the debates over using FF materials, so I figured who better to ask than the bow builders. I'm not wanting monstrous speed from traditional bows, but if something as simple as a string replacement is going to improve performance some it seems like a good thing to do. Especially with lighter weight bows. Various string materials make for more ways to make tuning adjustments.
Sam

[David Ricke]

Sam, Best way to make a bow ff safe. Don't dry fire it. Now that I have stated the obvious, reinforcing the tips is the only logical conclusion. Good Hunting Knifemaker

[Roy Steele]

I've built selfbows for 20 years.And have never did any thing special.And have used FF on my bows and told anyone that have have gotten a bow they could use one if they wish.Never that a bow break because of them.
  Some beef up there bows make tips heavyer or what ever no need to.

[sffar]

"Best way to make a bow ff safe. Don't dry fire it."

True. It happens, though. Could be one situation where the less stretchy string makes a disastrous difference.
Padded loops, along with heavier arrows, must make whatever additional shock FF imparts pretty marginal. No disaster stories. A very safe bet to use, judging by people's comments. Not one person's said "Don't dare use it!"

[Tucson-John]

Again speaking only for myself: Look at the logic of the issue. FF does not stretch to any great degree such as Dacron, etc - Therefore there is little to no shock absorption via the string. the advice: "don't dry fire" is sound advice. The advice that the tips are a point of friction (& abrasion) is logical also. That being the case I have used FF on one re-curve for several years but it was a modern (modern materials and mfg technique) bow.

I (personally) would not use FF on a self bow nor would I use it on a bow of any lengthy age (older than perhaps 25 yrs) as techniques have changed quite a bit in lamination materials, adhesives, etc.
However, that does NOT mean that some bows of decades old construction could not stand up to a FF string. As it's my belief that the majority of spring phenomenon is within the limbs and the string takes much less energy from the release of that energy. The idea of using an arrow of a certain weight may hold for many bows as arrow energy displacement issues may imperil the bow once a certain level is crossed.
IMO, There would need to be caveats to the question; so as to directly answer that with any degree of simplicity.

[Jason Jelinek]

BTW, linen strings were used on selfbows for hundreds of years (probably longer).  Linen strings stretch very little, I think less than even FF.

I personally think that if your bows limbs are thin and wide (like most recurves), they should be reinforced in thickness.  B50 has allowed bowyers to get away with thin and wide tips with little reinforcement.  Limbs with narrower tips should be able to stand up to FF better than wide, thin ones.  I reinforce mine with overlays anyway (self and glass lam bows).  I like the looks of the overlays.

[Pete W]

I use FF type material on all my bows, and almost all my strings areDF97, 10 strands with 16 strand loops. Carbon, glass and selfbows all get the same strings.
 Some of the older bows I have see had very thin wide limbs, with no reinforcing at all. Did they not also have some splitting issues even with Dacron from time to time? What did they blame it on then? Is the FF type string being blamed for a weak link in design and workmanship?
 Sure we see many old bows still in use, but there are many that failed before FF was being used.

 Pete

[Davt]

Fast flight is more of an issue with a recurve due to the area and way the string contacts the limb. I use fast flight on most of my self bows for a better feel. Some however shoot better with dacron. Also, on longer bows the stretch of dacron can lower draw wt a few pounds and will use that to tune bows a bit.