Carbon limbs Question for bowyers

[owlbait]

I see more bowyers offerring carbon in their limbs. Seems there are different configurations also: back, belly, both. What is the advantage? Is the performance or durability worth the extra cost? Years ago my friend Tom Cable of Windstorm Archery used what was called e-glass as a thin laminate in the core for stability and to resist twisting. Seemed to improve performance. Is this what carbon does?

[owlbait]

Non-Bowyers, please feel free to share your knowledge or experiences  

[Apex Predator]

I've never used it, but have read a lot from those that do.  The bowyers in the know, that aren't trying to sell you, will tell you that it only adds performance if it's on the back, and only a few FPS at that.  If it's located anywhere else in the limb stack, it's considered an expensive "racing" stripe.

[Ghostman]

I've had a few bows with carbon in the limbs. In my experience carbon adds stability and torsional strength to a limb. It seems to work best when placed on the back of limbs since it doesn't compress well.

In many recurves there isn't a noticable increase in speed maybe 2-3 fps. In longbow limbs carbon can increase speed up to 7 fps.

[Str8Shooter]

A lot of bowyers use it to increase speed, which depending on design it can do. I've heard all kinds of different numbers from bowyers but I would guess it isn't more the 5-7 fps on average. That is on the back. In the middle, save your money. Now some might not say 5 fps is worth the money but for someone who doesn't pull much weight or have a long draw that extra performance may well be worth it.

Now in recurves, specifically the ILF variety, carbon isn't used so much for speed as it is stability. Those manufacturers are using different versions of carbon to improve the torsional stability of the limbs. I've had some recurve limbs that felt like pry bars, you could barely flex them. The idea is that it will resist the effects of bow and string torque and minimize shooter errors. For close range shooting that may be of little value but at longer ranges that extra stability is noticeable.

The best thing to say about carbon is it isn't magic. Properly applied in a limb it can improve both performance and stability. But, if a bowyer adds it to the mix just because it's not going to improve much of anything.

Chris

[Tater]

If the bow is not specifically designed for carbon and it is just added in the lamination stack you will get a bit more stability and probably no increase in arrow speed.
      If on the other hand the bow is designed with carbon in mind and is used on the back or belly or both it reduces the limb mass and (in my experience) increases the bows efficiency and arrow speed noticably.
      I own both Carbon back and belly bows and Carbon back only and I see a marked difference in performance.

[LKH]

I have 3 Harrison's and he just cut another one in half in prep for putting the takedown in.  

They really perform well and I have to believe the carbon (has thin glass on top for protection) with the bamboo is why.

They are tough and I have stuck mine in the ground while sneaking (third leg helps balance).  I'll ask about why he puts in front and back.

[Whip]

At RER carbon is added to the back of the limb.  It will increase speed by about 3-5 fps.  Whether that is worth the additional cost is up to you.  My own personal preference is to skip the carbon, but that's what makes custom bows so nice - you get to decide how YOU want it.

[sswv]

a fellow once ask a very well known bower "what will the carbon do for me"?  

the bower answered "it won't do anything for you but it'll make me $75.00 richer".


 

[vermonster13]

You want the carbon on the belly. The limbs need to be designed for the carbon and the carbon itself that's used makes a difference. As stated above carbon is better stretched(on the back) and doesn't do well compressed(on the belly) and is a waste of money there for the most part, it also makes a poor core material. Just adding carbon to your existing design isn't going to give you all that much unless you're lucky. Guys like OL and Bob worked with their limb designs to get the bang out of the carbon. A few bowyers have carbon designed specifically for this application that they spent quite a bit of time developing. It takes experience to make a good carbon bow.

[owlbait]

Thanks for all the replies. I have learned alot from the GANG again today.
Mike Gerard  owlbait

[LKH]

Carbon on the belly does make a difference.  Harrison puts a layer of glass on top to protect the carbon.  He also puts carbon on the back.  Says it increases the modulus.

He is having a new style carbon made.  Its not cheap.  

Anything that reduces the mass in the limbs helps with performance.

[PV]

Been using carbon on the back for the last few bows. Drops the stack height and weight of the limb a fair amount. Still experimenting with the limb.So far picking up 3-5# like the RER.
Has a different feel than glass that I like.

[amar911]

Carbon backing is a definite plus on properly designed limbs. Find someone who knows what he is doing when he builds a carbon backed bow. I have no experience with carbon on the belly, but I know that there are very few people who do it well. David Knipes probably knows as much as anyone about who does the best work with carbon and ceramics on bow limbs. I bet he will tell you that Black Swan is the leader in those technologies. For carbon backed longbow limbs, I can definitely recommend Bob Morrison since I own several of his bows with foam cores and carbon backing on the longbow limbs. Gregg Coffey has been using carbon on the backs of a few of his Shrews for a year or more, and I have a Classic Hunter on order with foam cores and carbon backing. Gregg says the carbon adds speed to his bows, whether actionboo or foam cores are used. Chad Holm told me that he has successfully used carbon backing to increase performance. Obviously, the ACS CX longbows use carbon to great advantage, and I really like the way mine shoots, but John Harvard has reported difficulties with the carbon in his new recurve prototypes, with the longbow actually outperforming the recurve at this point in the design process. There are other bowyers out there using carbon (including some who have posted in this thread) who seem to have had good results with the material. I don't see any drawbacks to carbon backing when it comes to longbow limbs, other than an increase in cost. Recurve limbs present a more difficult challenge to design a carbon backed limb that actually functions better than one without carbon. David Knipes says that Black Swan has solved the mystery, but most others have not. Ask your bowyer what he thinks about carbon in the limbs and take his advise. Most won't want to use it in recurve limbs, and some won't want to use it at all. They know what works in their bows.

Allan

[Holm-Made]

I've only built only one Osprey longbow for myself that had carbon in it as an experiment.  I put it on the back and belly over action boo laminations.  Bow shot well for about 2 months then broke.  The belly lamination of boo failed at the fade out on the bottem limb which is where I would expect it to if it was going to go.  I'm told that carbon doesn't have the stretch or give to it that fiberglass does and puts more strain on the laminations and doesn't handle compression well.  I thought about building a bow with just carbon on the back and decided it wasn't what I wanted.  Bowyers tend to build bows they like themselves and I like the time tested fiberglass I guess.  
I should add that I don't have anything against using carbon in bows, I just have decided not to go in that direction.  Chad

[amar911]

Chad,

I knew you had used the carbon and thought it was pretty fast, and I knew you had experienced the failure due to the compression of the carbon on the belly, but I didn't know you had decided to forego the use of carbon on your bows in the foreseeable future. Your bows are very fast anyway, and I am enjoying my Osprey with the Bow Bolt a lot. I still think it is one of the best performing bows out there, and at a price that is an absolute bargain!

Allan