foam core???

[hydrasport205]

sorry if this is a dumb question  but what is a foam core limb???

[FerretWYO]

The foam core is just that. The core of the limb(inner laminations) is made up of a synthetic foam material as apposed to wood or glass. As for the foam I believe it is a ceramic base.

there are several people here who can give you a more in depth answer than I. Maybe Bob Morrison will jump on here.

[Ragnarok Forge]

Whats the point of the foam?  I can't see how it could contribute to the speed of the bow at all.  The only real benefit I can see is if it lightens the limb and the outer core provides the speed.  Downside here is that the outer core if compressed could crack or break causing a failed limb.

[hydrasport205]

TTT

[FerretWYO]

The foam is a very consistent material. It is also very stable across a large temperature range. As for the weight per cubic cetimeter it is very close to red elm. This is not foam like you would normally think of. It is a very durable material. I have a Pronghorn longbow that took a pretty good fall this year with no serious damage.

[Curveman]

I'm not convinced myself as to there being any advantage to a foam core bow. If you measure the draw force curve of identical bows you will see the same increments. So how then can the foam core bow be smoother? If it weighs the same as elm (in the example given), then how could a foam core bow be faster? Bow "smoothness" anyway, is mostly about string angles and limb geometry, little else. I have a glassless bow that will outperform the same glass version but that is because the carbon used is much lighter than glass and with all the other variables remaining the same you are inevitably going to pick up some speed. Carbon is more resistant to torguing as well so it will be more forgiving. That being said, I loved the foam core bow I shot but I would bet if you blind folded me I wouldn't be able to tell it from the wood version.

One uncertainty: FerretWYO brings up an interesting question, that of what materials would be the most stable across a large temperature range? How would elm compare? Would there be a significant difference that you would notice?

[Stone Knife]

I'm not sure about the technical aspect of foam core limb but I do have a recurve with carbon limbs with foam core. It is 46# @28 and my draw is close to 28" it put a four blade broad head in one side and out the other on a deer at a pretty severe angle so it had to travel through a lot of deer to get this done, that impressed the heck out of me.

[overbo]

I've talked w/ Bill Dunn about foam and shot his foam core design.Very impressive!I did notice w/ his design,is that it has a thick core and wonder if you use this design along w/ trapping the limbs if you would have something very special?

[KentuckyTJ]

I have a Morrison Cheyenne. It had a set of Boo core limbs then I bought a set of foam cores. You can definitely feel and tell the difference in Bob's limbs. I sold the boo limbs.

Smoother to draw with less shock and faster.

[Lenny Stankowitz]

"I have been using the foam cores for over a year now, I'm very happy with it and the only core I will use for my personal bows."  

This is what Bob Morrison said some time back about foam cores.  He might know a thing or two about limb design.

[Bill Carlsen]

Foam cores originated with FITA shooters who would shoot hundreds ofshots in very hot summer-like temperatures. The foam adds consistencey to the limbs under variable climatic conditions and in addition add some performance variables. FITA archers shooting at 100 yards are sensitive to changes in their equipment and foam limbs seem to dominate that scene for that reason. Not all bowyers are completely sold on foam. i have a pair of Winex foam core limbs on my DAS and on my wife's DAS. Best shooting bows I have ever shot. Sid from Border claims that limb design (geometry) is about 90% of a bow's performance. I will be getting a set of Border HEX V limbs in late winter with wood cores. Sid told me I would only gain perhaps 2 fps with the foam. I will be happy to report on my experience with the limbs  compared to the foam cores after I have had a chance to shoot them.

[Littlefeather]

I've done some research on foam cores because I've had all the same questions as you guys. What I found is that Hoyt has used foam limbs since 1972 in the olympic bows. Many, many compound manufactures are going to foam cores. I've also talked to numerous guys(non-bowyers) about the foam. Some are sold while others are on the fence. I personally have shot 4 bows by 4 bowyers who've used foam in the limbs. All bows drew smoother and felt like they were 10# less weight than marked. Doc Springer has a super sweet Morrison recurve with foam. It is an awesome shooter!

I've only heard limited bad about the foam. I'm currently waiting on a foam core Morrison to arrive. I'd love to hear from some bowyers about all the specifics. Hopefully Bob will drop by and have time to chat. Otherwise his phone is about to ring.     Where are you Bob?  

[vermonster13]

Properly made foam will give you a more torsionally stable limb than a wood core. It is more consistent and once a bowyer has their formula down for making weight, the limbs tend to be more even from bow to bow. You pick up two same model 50# bows from the same bowyer and they'll shoot pretty much identical where as wood core can have differences from limb set to limb set which is one of the reasons so many went to actionwood/actionboo cores at one time. Foam is forward progression from that material. I find them smoother to draw and a bit better in speed. While the weight is similar to Elm for some foams, the recovery time isn't.

[Bob Morrison]

What I can say about foam core is, No more torsionally stable than wood maybe less? that is where the correct layup of carbon comes in to play or the correct layup of Fiberglass. The foam is lighter than any wood, that is why you gain a few FPS, with less after shot vibration. It draws no moisture as Bamboo and woods will, Big problem in southern humidities.I have never had a failure that was caused by the foam, always some other component (wedge mostly in the beginning) It is quieter  and smoother than anything else I have ever used in Laminations. Speed is not much if any better than a Maple core. It is harder for us anyway to hit weights, I think every batch of foam is just a little different. In testing the Maple cores with carbon speed is pretty close. Feel isn't, I still prefer the foam cores over any wood or Bamboo. Smoothness, Preformance and quietness is all there, and as far as I can tell so is the durablity.

[leatherneck]

Not sure of all the technical stuff about the foam cores but I've owned both boo and foam in my Morrisons. The foam was definately smoother, but more so, it was quieter. I don't need a bit of silencers on my bow! I couldn't believe how much quieter it was. That,to me, means alot.

[Littlefeather]

Interesting stuff! I'm currently shooting the foam core Dakota. It came in earlier. I can certainly tell in drawing the bow the difference. It draws very smooth. I'm still messing with brace but she's very quiet right now. It certainly feels different. It shoots very well! CK

[JC]

Originally posted by Littlefeather:
Interesting stuff! I'm currently shooting the foam core Dakota. It came in earlier. I can certainly tell in drawing the bow the difference. It draws very smooth. I'm still messing with brace but she's very quiet right now. It certainly feels different. It shoots very well! CK

All the hogs in TX just went and finished their wills....they heard CK now has a Morrison. My oh my but the critters are in REEEAAAALL trouble now!        

[Littlefeather]

  Still shootin!

I want that old Morrison of yours JC. The curve you were shooting when we filmed the bunny bust. Still got it? CK

[Jason R. Wesbrock]

Originally posted by JC:
All the hogs in TX just went and finished their wills....they heard CK now has a Morrison. My oh my but the critters are in REEEAAAALL trouble now!            

I think he could kill a pig with a broomstick and a long shoestring. Obviously pigs don't talk much amoung themselves, or they'd have all gotten the heck out of South Texas years ago.  

[Ron LaClair]

We've been using foam cores on some of the Shrew bows for some time now with good success. Benefits have been on the plus side with no negatives so far.

My initial decision to try the foam was after talking to Bob Morrison. Bob has always been willing to share his findings with other bowyers, something that puts him on my list of good guys.  

Right now I'm shooting a Shrew prototype Model-T which has a foam core and carbon backed. I'm loving this bow, smooooth and fassst ...for lack of a better description.