Longevity of foam core limbs

[LongStick64]

I have been told by a few friends that compete in FITA Olympic style shoots that foam core limbs have at best a few years of longevity. I thought that was weird considering that the foam is not a natural product like wood and that should have a longer life cycle. They have told be on what they have noticed on the competition circuit that more and more shooters are going back to carbon/wood limbs over the carbon/foam. What do you all think. We have some really good foam limb makers here, Morrison, Black Swan and Zipper. Would like to hear their point of view.

[Hess]

I had a set of recurve limbs (that I ordered new) and when I pulled them out of the box the foam had a visible crack where the "hook" curves towards the end of the limbs.  And it was on both limbs.  I called the bowyer and he was not worried about it...but these were limbs I just spent upwards of $600 on.  Sold them shortly there after and have no interest in getting another set for any of my bows.  

That was my only experience with foam core limbs.

Shoot straight...

[Red Tailed Hawk]

Im interested to find out what some of our boywers have to say???  

[LongStick64]

Curveman,

I don't believe it's just the Koreans going back to wood/carbon. From what I hear it's been a general move. Also Samick is a Korean company, I doubt seriously if any top Korean archer spends a nickle on equipment.
I agree on the perception of foam vs wood in terms of smoothness. But what I'm concerned with is the notion that foam limbs have a short life cycle compare to let's say bamboo cored limbs.

[Davt]

I think we can get into trouble thinking that natural material does not last as long as synthetic. I have broken a few carbon fly rods but still have a 50+ year old orvis bamboo I fish with and my newer bamboo rods get more action than the carbon. As to the life of the foam core, we will have to wait and see thier track record. It would be interesting if one of the foam limb bowyers has done fatigue testing and could make that data available. Me, I prefer things as natural as possible given my limitations of effort.

[Turkeys Fear Me]

Originally posted by LongStick64:
I have been told by a few friends that compete in FITA Olympic style shoots that foam core limbs have at best a few years of longevity.


 We have some really good foam limb makers here, Morrison, Black Swan and Zipper. Would like to hear their point of view.

Two things:

1.  With all due respect to Morrison, Black Swan and Zipper, I would tend to defer to the companies that have made literally tens of thousands of sets of foam core limbs, and hundreds of thousands of sets altogether.  Of the three major limb manufacturers, two of the three incorporate foam in the core of their flagship limbs.

2.  Most top level Oly and FITA shooters are "sponsored shooters".  They shoot the limbs they are paid to shoot or at least the limbs they are given.  In regard to the durability of foam cores being "a few years," (which I doubt) I would wager to say that even if it is true, the limbs of a top level FITA or Oly competitor go through more shot cycles in three years than what our limbs would do in two lifetimes...not to mention that the vast majority of these shooters are using arrow weights that are MUCH lighter than we would ever consider using.

[LongStick64]

the limbs of a top level FITA or Oly competitor go through more shot cycles in three years than what our limbs would do in two lifetimes...not to mention that the vast majority of these shooters are using arrow weights that are MUCH lighter than we would ever consider using.  

I agree with this completely. But given that, what interests me is if these top competitors are moving away from foam, they are doing it because of a competitive advantage don't you think.

So what is the advantage of foam for us, especially since we are shooting heavier arrows. I understand on principal that the foam is not affected by the weather. OK. But if that statement is true, if the wood cores are affected by the weather.....by how much ? would we even notice the change ? especially since most of us are not taking 90 meter shots.

Please understand I'm not trying to bash foam, just hoping to get educated. And I fully admit that I probably wouldn't be able to tell the difference anyway.    

[Turkeys Fear Me]

Originally posted by LongStick64:
I agree with this completely. But given that, what interests me is if these top competitors are moving away from foam, they are doing it because of a competitive advantage don't you think.

So what is the advantage of foam for us, especially since we are shooting heavier arrows. I understand on principal that the foam is not affected by the weather. OK.

Well, yes and no.  First of all, I think the verdict is still out on whether or not there is a substantial switch from foam to wood by the "top competitors."  By virtue of the fact that two out of three of the major limb makers are still using foam in their flagship limbs, not to mention that virtually all of the "second tier" limb makers are using foam in their top of the line limbs, I think you might just be getting one person's opinion on what the top level competitors are doing.

Second, the top level competitors don't always make their equipment decisions based on what you or I might consider to be a "competitive edge."  Phil Mickelson didn't switch to Callaway because he thought it gave him a competitive edge.  Actually, an argument could be made for the exact opposite.  If that were the case, every top competitor would be using exactly the same setup.  95% of all professional golfers use Titleist balls, yet Tiger uses Nike.  In his hayday, do you think if Tiger switched to Titleist, he would have won less?  How about if Phil would have switched to Nike, would he have won more?

As far as the benefits to us.  Like you, I'm not totally sure there are any (at our level).  However, I think we could both agree that much of what we do is mental.  If we are convinced that we will shoot better, we probably will.  Also, if we agree that foam is more stable at different temperature extremes, who experiences more variance in temperature and weather conditions, target archers or hunting archers?  Sure, target archers compete in 80, 90, or even 100 degrees but how many compete when it's 20, 10 or even -10 degrees.  Hunting archers do both. How about rain, sleet, snow, etc.?  Maybe it's MORE important for a hunting archer than it is for a target archer... Granted, we aren't shooting ninety meters but then again they aren't hunting pigs in Arizona one day and bears in Alaska the next.

Lastly, I can't speak for the the custom bowyers that you mentioned but my gut tells me that if they had any question about durability, they wouldn't be using foam.  Think about this for a second.  If Hoyt gets 50 sets of limbs back that failed, it's one thing.  If Morrison or Zipper gets 50 sets of limbs back, it's game over.

Oh, and by the way, I never took it that you were bashing foam.

[Sixby]

I'll definately deferr to Bob Morrison. He has convinced me that foam and carbon is good. I have built a ton of carbon limbs and am still experimenting with foam. So far my experiments with foam concurs with what Bob has said. foam good . It is homogenous material and when you use high quality foam you will get no uneven pressures within the limb that you can get with even the best of wood cores. I believe that foam and carbon are made for each other. JMHO. As to longevity. I have no comment on that at this time. However a lot of bowyers have problems with longevity when using carbon. I believe that limb design and improper use of carbon is the culprit . Not carbon itself. Balance of the working forces withing the limb is absolutely critical . Not allowing forces to build in any area but being distributed evenly through the length of the limb is critical. Knowing the working qualities of carbon, especially using double carbon is essential. I believe using foam is much the same. What I have seen with foam is a lot of bowyers sitting back waiting for a few to prove the product so they do not have to spend either the time or money to do the prototyping.

What I do know is that performance wise . and that is in all respects, the best limb I have built was an all composit limb built with S glass, carbon and foam core. Steve

[artifaker1]

I have all hunting stuff but I shoot with several FITA style archers and they seem to get new limbs every year or two. I'm pretty sure that their limbs start to loose some punch after so many shots at 6, 7 or maybe 8 grains per pound. I avoid buying used limbs from them for hunting, unless they were not shot a lot for some reason.
I have several sets of single carbon foam limbs from Morrison and one set I have shot many thousands of arrows through. I mean thousands (D longbow @38lb). And I shoot these limbs at about 12.8 grains a pound. They have not lost any punch, still shooting the same arrow as in the begining, although I have made advances in tuning and I am shooting a slightly heavier spine arrow with them to be forthcoming. I see no loss of performance with these limbs in the foreseeable future.
I Chrono-ed these limbs once just to see where I was at. On a twenty inch riser with a ten strand 8125 string with cat whiskers. 513 grain arrow with a measured draw of 29-3/4 the limbs were measured to be at 40lbs there (I have this riser turned down all the way to get more deflex). They were making a steady 160 FPS with a fingertip release @ 12.8 grains per pound. Outside at the range this set up gaps at about 60 yards. My other limbs which are more of hunting weights I shoot at 12 grains per pound and the Morrison Longbow limbs are at about 170 FPS with every thing the same as above but the arrow weight. I just picked up some 51lb CF recurve limbs and they are faster but I haven't got around to chono them.

Shoot heavy arrows, your limbs will last longer, no mater what there made out of.

[Turkeys Fear Me]

Originally posted by Curveman:
I think I've pulled things way away from the original question.  I apologize!

Heck, I thought we WERE discussing the original question.


 

Originally posted by Curveman:
The Korean Olympic archers are all going back to wood combo largely due to the cost of the materials I bet.

Where are you seeing that the Korean Oly archers are all going back to wood?

[LongStick64]

Not the only ones pondering this issue it seems

 https://www.archery-interchange.net/forum/equipment-reviews/12369-limbs-foam-vs-wood.html

[Bob Morrison]

I've been using foam for going on 3 years now. I've had fewer limb failures with foam than we had with Bamboo. None of the failures were from the foam itself. I have had the foam crack in the tight bend in the recurve while gluing up limbs. Never had a problem with any breakage in that area, the same resin is used in the making the foam and when gluing up crack fills in and is just visable and affects nothing. foam will not draw any moisture any wood or grass will. Foam may not be for everyone, but for me personally it's a no brainer, it is faster, smoother and more weather tolerant than any wood. In the next 5 years you will see more bowyers using it, some that claimed it is not worth the extra $35

[amar911]

I'm certainly not an Olympic shooter, and not even a true target shooter. I shoot at targets for fun and to practice for hunting. I am a fairly good shot, but there are many thousands of archers who shoot much more accurately than I do. I have somewhere between 40 and 50 trad bows and have shot a lot more over the last half century. Most of my bows have wood (including bamboo) cores, but a number of my newer ones have foam cores, and some of those also have carbon backing. The "feel" of a bow encompasses many things. The most important factor is good design. However, materials do make a difference. Foam cores and carbon backing cannot make a poorly designed bow shoot well, and some extremely well designed bows are not amenable to the use of foam and/or carbon.

One example of a bow with an outstanding design that could not accommodate foam cores (or carbon backing at my draw weight) is the new Brackenbury Peerless static tip recurve. The Peerless shoots at least as well as any bow I have ever had the privilege of shooting. Bill Howland experimented with the use of foam cores in the bow and was unable to adapt the foam to the design. I would put the Peerless up against any other bow made as far as the overall balance of performance, smoothness, stability, noise level, speed, and any other characteristics that archers find important in a great bow. My Peerless has wood (I'm pretty sure the wood is bamboo) cores which obviously have been used a very long time in the construction of bow limbs. Foam cores would degrade the performance and other great characteristics of the Peerless due to its design, and in my draw weight, so would carbon backing.

I'm sure there are other bows like the Peerless that are not conducive to the use of foam and/or carbon, but for those that are, these materials can definitely enhance the feel and to some extent the performance of the bow. There is no doubt in Bob Morrison's mind, or mine, that his foam core bows feel better and perform a little better. With carbon backing, they perform significantly better and feel great. As to whether the limbs will degrade quicker over time than wood cores, I can't really say, because I have not had foam core bows for more than a few years. I can say that I prefer my Shrew Classic Hunter longbows and any of my Morrisons (either longbow or recurve) to have foam cores and carbon backing, and I say that with having more boo core bows in these bows than the foam or foam/carbon models. I also disagree with those who think that a draw/force curve can adequately describe the smoothness of a bow, either in its loading (draw) or its unloading (release). The same thing goes for fly rods, since that analogy has been used in this thread. There is a good reason why bamboo rods are primarily collector's items, while carbon fiber rods rule the fishing lakes and streams.

Both natural wood core bows and foam core bows are great. Just pick the one you like and enjoy it. I expect that either material, if used by a good bowyer in a well designed bow, will last any of us a lifetime if we properly care for the bow. And depending on the bow and its design, either one of the materials may be a better choice than the other. If in doubt, ask the bowyer which material he thinks will work better in his bows.

Allan

[amar911]

By the way, I don't think there has been any bowyer in the traditional archery business who has done more research or experimentation with foam or foam/carbon bows than Bob Morrison. He is a true pioneer and a great craftsman. His bows are at the top of bowyer's art. He has also freely passed on his hard earned knowledge to other bowyers so they could build better bows that compete with his. You won't find a better or more honest bowyer anywhere. I have many of his bows and think they are all great. But the foam/carbon limbed Morrisons shoot better than Bob's boo core bows. Bob's designs have been tailored to bring out the best in the foam and carbon -- and that took lots of R&D on Bob's part, costing him tremendous investments in time, effort and money. I was on the waiting list for my Peerless for 2 1/2 years, and it was worth the wait, but I can get a Morrison that shoots comparably right off Bob's website -- and I have done that and always been thrilled with my purchases. I started buying the foam core Morrison limbs shortly after Bob started making them, and I have not had a single problem with any of them. Bob also helped Gregg Coffey when Gregg started making foam core and foam/carbon limb Shrews. I have Gregg's first prototype foam core Shrew, and it is one of the best shooting bows I own. I now have several foam/carbon Shrews, and they are basically the same as the original foam core Shrew but with better performance. The Shrews and the Morrisons are very different designs of bows, but both brands are great bows that have only been made better with the advanced materials. I also have had zero problems with my foam core  or foam/carbon Shrews.

Allan

[Sixby]

I build a static recurve with an exceptionally tight radius recurve. I tried foam and It broke the foam as Bob described. .I could not use it or carbon in that static limb.This brittleness is the one fault I find with it. I will try to develope a static that will handle it next year. Lord Willing.

[LongStick64]

Thank you all for your information, this has been a very informative thread for me.

[maxwell]

This has been an interesting discussion-  For me I have found my foam core limbs with carbon seem to work better.

[Bob Morrison]

We offer Bamboo, Maple, foam Cores in our limbs.
Maple as a standard. Its as fast as the Foam cores not smooth or as sweet as foam or Bamboo.
Bamboo is 2-3 fps slower smooth and sweet on release.
Foam is fast, smooth and sweet. Will not draw moisture. Wood or Bamboo will draw moisture in Hot Humid areas of the country and can cause glue in the limbs to lose its bond with the core and just roll up and delaminate.
I've been working with wood over 50 yrs and the more time I work with it I realize I will never come close to understanding what its going to do. But I do know that wood even with a great finish on it will draw moisture in hot humid areas and will lose moisture in very dry areas this is a fact. I have not see that will foam.
Foam under clear glass will never be good looking. You can use veneers or snakes to dress it up. It will never be wood or natural, but the glues & glass we use isn't neither.
I also like the look of wood better, but like the feel and preformance of the foam even more...
BTW Foam has been around in recurve limbs around 30 yrs thanks to Earl Hoyt.

[LongStick64]

Bob,
Can you explain the difference in backing foam core limbs, carbon vs glass. I would think the carbon would add considerable stiffness to the limb compared to the glass.

Thanks
Pete