# Limb material preference



## wags2 (Jan 26, 2009)

Mainly in the intermediate/beginner limbs.

I have been shooting a wood/glass limb for about 9 months and really like the feel. I have shot my carbon/wood limbs that at the same weight feel way heavier and aren't nearly as comfortable to shoot. I'm assuming it is just the difference in material. 

For me the wood/glass limbs feel much softer, with these two limbs I can't see much performance difference. Sight marks are basically identical.

Who makes the best wood/glass limbs? I basically shoot for fun but have shot more tournaments this last year and have enjoyed shooting Olympic recurve more than I would have ever thought. Shooting 33.5#'s currently and hopefully around 38#'s this outdoor season. That will be the most I'll ever shoot(shoulders are the main concern).

Current limbs are sf axiom + 34#, sf preminum carbon 36#. Both are shorts, and draw length is 28".

Any limb suggestions would be appreciated.


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## foryn (Nov 13, 2013)

Premium Carbons are not really and truly carbons. They have a small strip of "fabric" carbon near the wood bound together and bulked up with fiberglass (why it feels heavier)

Until you get into anything like full "unidirectional" carbon, or cross carbon that is actual chunks of carbon, there really shouldnt be much of a difference. At higher levels. the unidirectional carbon adds a bit more flexibility than the fiberglass and coins the term "feels smoother" but usually have that fiberglass element to keep it stiffer.

Cross Carbon adds things like helping prevent limb twist.

For beginner/Intermediate, the Kaya K1 are going to be about the only thing different because it ads the element of a tight weave fabrick (kevlar) to add to the flexibility.

Foam limbs are typically a bit more stiff thanks to the nature of the element. but combined wit the kevlar it moves it towards the smoothness of wood a smidge while keeping more rigid/snappier.

Limb profile determines the real Smoothness more than anything, I have a high profile Winstorm II limb that has somewhat of a "let-off" effect when pulling through the clicker.

Moral of the story, they are really about the same, with the exception that the Axiom+ limbs use less fiberglass and weight wise are lighter (maybe why it feels more comfortable).

I stick to anything that has a good limb profile (be it wood or foam) but unless you spend around $300+ the carbon is almost useless and more of a "sales" gig than anything.

if you get more carbon to replace the fiberglass (300+ range ish) then it gets lighter again... so unless you hit your final weight. id stick to the axioms for a while and jump straight into a higher priced limb and skip the middle-low range. save your pennies and stick to whats comfortable. we have a very large range of axiom+ with my friends to help everyone find their final weight. after that we jump to the higher levels of carbon and the better types of carbon.

Hope this helps, and by no means my word is law, just showing my general research, since 99% skip actual limb weight affecting anything and just simply say "oh these limbs are smoother..."

Also note (a 30lb bow with the limbs turned all the way out will feel lighter and smoother than a 30 lb set of limbs with the bolts all the way in) Basically meaning you pre-load the limbs you start the wonderful effect of stacking much earlier and would feel "stiffer" than the other way around. So I always have my weight with the bolts all the way out.


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## wags2 (Jan 26, 2009)

Thanks for the info.

I'll mostly likely try and sell the preminum carbon limbs and buy another set of wood/glass limbs. I've shot the heck out of the axiom limbs somewhere in the 8,000 arrow range(enough where the white is wearing off in the limb groove on the bottom limb). I shoot typically 4 times a week, arrow count depends on the day but typically around 100 arrows or so. 

I'll take a look at the Kaya limbs.


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## limbwalker (Sep 26, 2003)

Usually, where those less expensive limb will fail is in the nock overlays. They will blow up without warning. 

Otherwise, I've seen some $90 limbs last and last, and shoot decent scores too.

My wife uses an inexpensive pair of old Hoyt wood/glass limbs, and she shoots outdoors to 70 meters with them, just fine and dandy. 26# on the fingers with Medallion XR 1500's - work like a champ.


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## Vittorio (Jul 17, 2003)

After beginning level, second step here in Italy probably for 80% of new archers are the SF Elite Carbon limbs. Good enough to win the world indoor Junior championship for Junior girls last year in Nimes.


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## grantmac (May 31, 2007)

In my experience you have to spend about $250 before you get a better limb then the Axiom+.

-Grant


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## Borderbows (Apr 4, 2009)

foryn said:


> Until you get into anything like full "unidirectional" carbon, or cross carbon that is actual chunks of carbon, there really shouldnt be much of a difference. At higher levels. the unidirectional carbon adds a bit more flexibility than the fiberglass and coins the term "feels smoother" but usually have that fiberglass element to keep it stiffer.
> 
> .


Carbon is actually less stretchy than glass. 
both glass and carbon have linear rates of strength gained per unit of tension or compression.
so the material has NOTHING to do with smoothness.


the limbs geometry dictates its smoothness.

the facts to look at are things like why are static recurves smoother than working recurves...
Well, because the defend their shape through the draw cycle.
so cheap limbs tend to have parallel cores in them, making them stiff at the outer limits of the limb.
while expensive limbs tend to have a taper in the core. the taper allows the outer parts of the limb to save mass, but also reduces the smoothness.

add to this mix, the fadeout. the part of the limb where the limb butt "fades out to nothing" this can be longer, making the limb shorter. this will reduce smoothness.
and just like knife blades. the fadeout can be hollow ground meaning its more "working" meaning the limb becomes longer...

so these as well as limb shape dictate smoothness. 

since this info is absent in the limbs models, smoothness is attribubuted to the materials. when infact, it makes little to no difference at all.
we have changed limb materials, from Glass, to Glass carbon, to Carbon and S2 Glass. through to utterly glass free limbs. and the DFC comes out the same, if the same taper, same fadeout and same former are used.

The resulting smoothness is geometry related. and all linear materials will deliver equal smoothness if the relationship of profile and cross sectional area along its length remains equal...


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## jaredjms (Oct 24, 2007)

Border, thanks for the info. I'm curious to know your take on wood core vs foam core. Most people believe all things equal the wood core is smoother. Do you agree with that or do you believe that, as you say, it is strictly the geometry that dictates smoothness?


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## Borderbows (Apr 4, 2009)

jaredjms said:


> Border, thanks for the info. I'm curious to know your take on wood core vs foam core. Most people believe all things equal the wood core is smoother. Do you agree with that or do you believe that, as you say, it is strictly the geometry that dictates smoothness?


if you take the core on its own.
take it down the the side profile of the limb. and pull it back you would be lucky to get 1lbs showing on the scale.
if you took bamboo, vs maple. i doubt the difference for the same dimensional spec of material would yeald 0.05lbs difference.

sandwich that core inbetween two composit layers and you will get say a 40lbs set of limbs.
so you might have a difference in two limbs of 40lbs at 28" which deliver 0.05lbs of difference.

now smoothness is about how you GET to 40lbs at 28". 

how does that work?

the next question is...

if i make 3 identical sets of cores on the machine at the same time. one bamboo, one maple, and one synthetic.
so all have the same thickness. same taper. same dimensional spec. and i make 3 sets of limbs from the same fadouts and laminations

i would honestly expect the same draw weight on the resulting limbs.

so how would a change in material, that delivers the same draw weight, that has the same geometry throughout the draw deliver a different DFC.

so, the next question is... on 2 limb models where you can have wood core vs sythetic. does the limb have a differnt taper? or does it have a different fadeout?
or is the limb cut 1/2" further round the former... rememebering that you can cut a meduim limb out of different start and end points on the former...

all this changes the geometry of the limb, and will change the feel, yet can come with the same model name... "just a change in core"
now that alot of manufacturers are keeping the core choice at the same price, there is no need to make one "better" than the other. so perceptions might start to change...


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## jaredjms (Oct 24, 2007)

Great, thanks for the info


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## theminoritydude (Feb 11, 2013)

Archers like to equate smoothness with performance. But everyone has their objectives, the only important thing is to know which objectives one is going for.

The first time I held my Inno EX Power upper limb in my hand, I knew it would be fast. The feel didn't matter. But it felt good during the draw anyway.


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## Vittorio (Jul 17, 2003)

One more thing to add is that "wood" core for some (expensive) limbs does not mean they have a layer of solid wood as core, but a layer from stratified wood thiny layers glued toghether, sometime alternated with other materials (most famous: W&W Sinergy limbs, titanium +wood stratified core). As far as I remeber from a presentatiton of Hoyt formula limbs held in Milano, also Hoyt is using stratified wood as core of top limbs, not solid wood. This solution gives more consistency to the core and less needs of balancing the center of the limb after making first cooking. Diffeence in smootheness? Just an urban legend. As Borderbow has said, if the shape of the limb and the tapering of the core is the same, draw curve will be the same independently from material of the core. 
Reason why majority of top level shooters use wood core limbs despite them being slightly slower than foam limbs, is because general feeling is that still now, foam core limbs are less consistent than stratified wood core limbs in terms of performance. At least, shooting >45#. I repeat, general feeling , may be not reality.


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## Borderbows (Apr 4, 2009)

Vittorio said:


> One more thing to add is that "wood" core for some (expensive) limbs does not mean they have a layer of solid wood as core, but a layer from stratified wood thiny layers glued toghether, sometime alternated with other materials (most famous: W&W Sinergy limbs, titanium +wood stratified core). As far as I remeber from a presentatiton of Hoyt formula limbs held in Milano, also Hoyt is using stratified wood as core of top limbs, not solid wood. This solution gives more consistency to the core and less needs of balancing the center of the limb after making first cooking. Diffeence in smootheness? Just an urban legend. As Borderbow has said, if the shape of the limb and the tapering of the core is the same, draw curve will be the same independently from material of the core.
> Reason why majority of top level shooters use wood core limbs despite them being slightly slower than foam limbs, is because general feeling is that still now, foam core limbs are less consistent than stratified wood core limbs in terms of performance. At least, shooting >45#. I repeat, general feeling , may be not reality.



I beleave Black Widow have been using a "stratified" core in their limbs since the 80s. it makes sence as it reduces the skill and hand selection process of someone selecting good grain in the timbers. it also makes sense in that the wood can have slight variations from tree to tree. the specs you see on timber density and its other properties are related to an average.
this takes skill in selecting timbers that will deliver a production consistency where the managers and bean counters know whats going to come out the factory.

Hand selected timber is every bit as good than stratified timbers...

look at wooden arrows. they require straight grain timber hand selected for shafts.... limbs are also the same... unless you make it into plywood and engineer out the irregularities in it for production reasons.

this is my reason for thinking that foam cores were brought about in the first place. a core material that is consistant from the start of the production run to the end....


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## limbwalker (Sep 26, 2003)

> the limbs geometry dictates its smoothness


All else being equal, yes. 

However, riser geometry (amount of deflex, limb pocket angle, amount the tiller bolts are adjusted in or out) and overall length (which affects geometry and the amount the limb is flexed) has a lot to do with perceived "smoothness" as well.


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## Borderbows (Apr 4, 2009)

limbwalker said:


> All else being equal, yes.
> 
> However, riser geometry (amount of deflex, limb pocket angle, amount the tiller bolts are adjusted in or out) and overall length (which affects geometry and the amount the limb is flexed) has a lot to do with perceived "smoothness" as well.


Yes very much so.

Though in the ILF world its possible to make a limb that has a significant difference in smoothness with geometry than any riser could achieve.
the rule of thumb is 2lbs per inch at full draw.
the ILF 10% weight adjustment is based on this.
we have just had a customer say that with 2 full turns on thier limb bolts that they have 0.1lbs of draw weight difference. ( i think there is a measuring error but the point is valid)
the problem they have is that thier setup from 28-29" the bow scaled at 36lbs. But gained 0.4lbs. 
The 10% rule on the risers is based on approx 2" more draw length. 2" at 0.4lbs gain is 0.8lbs difference wound in vs wound out.

No riser has ever achieved this level of change bow traits.
its possible to use the same limb butt. carbon laminates. And wood core and make a limb that gains 2lbs per inch. 1.6lbs per inch. 1lbs per inch or even 0.5lbs per inch simply by changing its profile. 
All 40lbs bows at 28" all meduim limbs. All on a 25" riser


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