[jons]

Just interested who came up w/ foam core in limbs. I got a bow made back in 1999 and the bowyer told me he put a special core in the limbs for me, when asked what it was he said it was foam and asked for specific he wouldn't go into it and just told me that I would like it. Got the bow and I was very surprise by the performance and quietness, still have the bow. I shot other bows w/ foam and carbon and wasn't that impressed w/ several of them. So, what is the difference in foam and the configuration of it in the limbs? Do not want to step on anyone's trade secrets. Infact, my hunting bow is back to red elm 46# that cast an arrow about as good as any.

 

[John in NZ]

I think it's much more about what's wrapped around the foam than the foam it's self.
I also believe the foam is more about feel than performance.
But I could be wrong.

John.

 

[j-san]

As I understand it, it is the back and belly laminations that bear the burden of the tension and compression forces and give the limb the draw weight and performance characteristics. The core material serves to provide a separation between the working laminations much like the vertical portion of an I-beam. A wider separation would provide heavier draw weight.

Ideally, the core material would be massless so as to maximize limb efficiency and arrow speed, but that is not possible. Foam cores can be made lighter than wood, so often times, foam cored limbs are slightly faster. The benefits of foam over wood is that its characteristics can be carefully controlled to suit the particular limb design and being synthetic, is not susceptible to the variations in the environment.

I am not a bowyer so I cannot claim this information is entirely correct. This is what I am led to understand from reading the numerous and informative threads on this forum and others regarding limb design and limb materials.

I own both foam cored and wood cored limbs and both shoot equally well. I never noticed any changes in how my wood cored limbs performed in different environments and even if there was a change, I probably am not a good enough archer to noticed the difference.

 

[Kenlbear]

As I understand it, it is the back and belly laminations that bear the burden of the tension and compression forces and give the limb the draw weight and performance characteristics. The core material serves to provide a separation between the working laminations much like the vertical portion of an I-beam. A wider separation would provide heavier draw weight.

Ideally, the core material would be massless so as to maximize limb efficiency and arrow speed, but that is not possible. Foam cores can be made lighter than wood, so often times, foam cored limbs are slightly faster. The benefits of foam over wood is that its characteristics can be carefully controlled to suit the particular limb design and being synthetic, is not susceptible to the variations in the environment.

I am not a bowyer so I cannot claim this information is entirely correct. This is what I am led to understand from reading the numerous and informative threads on this forum and others regarding limb design and limb materials.

I own both foam cored and wood cored limbs and both shoot equally well. I never noticed any changes in how my wood cored limbs performed in different environments and even if there was a change, I probably am not a good enough archer to noticed the difference.

I agree with this analysis. Thanks!

 

[bleslie]

Just interested who came up w/ foam core in limbs. I got a bow made back in 1999 and the bowyer told me he put a special core in the limbs for me, when asked what it was he said it was foam and asked for specific he wouldn't go into it and just told me that I would like it. Got the bow and I was very surprise by the performance and quietness, still have the bow. I shot other bows w/ foam and carbon and wasn't that impressed w/ several of them. So, what is the difference in foam and the configuration of it in the limbs? Do not want to step on anyone's trade secrets. Infact, my hunting bow is back to red elm 46# that cast an arrow about as good as any.

Circa 1986, Hoyt introduced the Carbon Plus limb in Syntactic Foam (invented and patented by Easton engineer Gary Filice).

I have 2 sets of Borders limbs that are identical except one is wood and one is their H foam. All things equal, according to my chrono the foam is 4 fps faster and it feels smoother on the draw. The wood cores feel ?better? on the shot and make more of a thunk sound vs the foams ping sound. Last summer I kept track of my practice 900 rounds. The average for the 10 best rounds with each set gave the foam cores a 4 point lead. About 10% of the high/low spread over those rounds.

I haven't run into any inconsistencies that could be attributed to temp, humidity etc with the Borders wood core limbs but have had other wood core limbs where I could definitely tell a difference in performance between 70 and 30 or 90 deg.
I'll pay the extra $ for foam on my future purchases not because it offers any huge advantage but mostly just because it makes me feel better.

 

[Larry Hatfield]

those first generation foam core limbs from hoyt had a finite life. they blew up randomly and the archer would stand there with a little snowstorm of small spheres raining down on him/her. the foam and the processes have changed a lot since then. there are some advantages in using them for fita rounds and general target archery and in conjunction with carbon laminates. I prefer maple for every thing else just out of habit.

 

[Sid]

Circa 1986, Hoyt introduced the Carbon Plus limb in Syntactic Foam (invented and patented by Easton engineer Gary Filice).

I have 2 sets of Borders limbs that are identical except one is wood and one is their H foam. All things equal, according to my chrono the foam is 4 fps faster and it feels smoother on the draw. The wood cores feel ?better? on the shot and make more of a thunk sound vs the foams ping sound. Last summer I kept track of my practice 900 rounds. The average for the 10 best rounds with each set gave the foam cores a 4 point lead. About 10% of the high/low spread over those rounds.

I haven't run into any inconsistencies that could be attributed to temp, humidity etc with the Borders wood core limbs but have had other wood core limbs where I could definitely tell a difference in performance between 70 and 30 or 90 deg.
I'll pay the extra $ for foam on my future purchases not because it offers any huge advantage but mostly just because it makes me feel better.

in our opinion the Foam core was to solve a issue that is related to the composit.

Glass expands with temperature. while the resin that holds it together, softens, meaning a loss in poundage (marginal)

Carbon mildy contracts, but the resin softens. so its deemed inert. tempertaure nutral.

Most limbs are powered by glass. so in that lies the marketting behind "foam" cores.

IMO
http://gwcomposites.com/carbon-vs-fiberglass/