What is the value of adding a Carbon lamination?

[cunruhshoot]

I am getting ready to build yet another bow and I typically purchase my lams from Bingham...I have looked at Kenny's site and may give that a try this round. But my question is related to the value of adding a carbon lam. I have a Tomahawk bow from 3 rivers that has a carbon lam and got it because they said it was better. What does better mean?

[LittleBen]

For them better means higher price and larger profit margin. I would assume. Obviously I'm being skeptical.

Carbon is stronger and/or lighter than glass so ... I guess you lower the limb mass and increase efficiency.

[Troy D. Breeding]

My understanding is,,, if it's on the outside of the limb it increase proformance. If it's inside the limb it adds stability with little increase in proformance.

JMHO from what I've heard. Can't say with fact because I've never used carbon in or on a limb.

Troy

[Sharpend60]

I have heard mixed things.
Negatives include, lower service life and a 'twangy' noise.
There are many 'increased performance' claims. Which may or may not be substantiated.
Lots of bow makers have it as on option on their bows.
Granted, I havnt built a glass bow but have been paying attention for many years.

[fujimo]

always remember that carbon( graphite) is a material that has very high compression resistance properties.
fibres that have better tension qualities are glass, nylon,kevlaar and spectra(dyneema) - in ascending order.
some are hard to work with, some dont finish sand well, and most are probably over engineering for a bow.

just some thoughts on properties!

[cunruhshoot]

Thanks for the input...I think I will pass on the carbon it adds about 30 bucks to the material cost to the bow...but so far it does not sound like it adds 30 dollars worth of value.

[chackworth3]

I have used carbon on some bows as a core. The pros I have seen are it is lighter and you gain a few fps, however it does have a "twangy" sound as mentioned above.  I would rather use something like action-boo which is almost as fast but alot more quiet with much less vibration...

[Crooked Stic]

Carbon used on the front of the limb in place of the glass may gain you as much as 4 fps. not a certain thing though. Due to it being more stiff it feels better after the shot also reduces lam stack to get the same poundage. It wont stand up to dents and dings as well as glass and does has a ring to it when the bow comes back to brace.
In my opinion is not worth the extra price in a custom bow. If you want a fast bow - design has more to do with it than just adding carbon. A lot of hype but to each his own.

[Pete W]

I have shot and tested a few bows with carbon. The results vary drasticly. Because it is carbon in the limb does not guarantee anything. It can be no more than a black line, to a high performing very stable limb.
 Not all carbon is the same , and where in the limb it is used  changes what it adds to the bow.
 I don't believe that there is a one size fits all when we use carbon.
 Many Bowyers use it because it sells well, some use it because they have found they can add stability, some have found  they can gain performance. Some haave added stability and performance.
 It is not a magic fix for a dog of a bow.  Those bowyers with success have done a lot of trial and error to achieve the benefits, while others are just using it because it is a sales enhancement.
 It is not a magical material that gives spectactular results without research, and trial and error.
 The  fact a bow has carbon means nothing if it is poorly chosen material and aplication . All carbon is good for something, but not all carbon is good for a bow.
Pete

[Furtaker]

Well said Pete !!!!

[canopyboy]

Originally posted by fujimo:
always remember that carbon( graphite) is a material that has very high compression resistance properties.
fibres that have better tension qualities are glass, nylon,kevlaar and spectra(dyneema) - in ascending order.
some are hard to work with, some dont finish sand well, and most are probably over engineering for a bow.

just some thoughts on properties!

I disagree.  While carbon has higher compressive capabilities than glass, it is 50% better in tension than compression.  Glass actually has about 15% higher compressive strength than tensile, although both are less than carbon.  (I am talking composites here, not solid glass or carbon for which I'd have to do more research.)

That said, what really gives more zip to carbon when used in the outer fibers of the bow is it's incredibly high modulus of elasticity.  It's very stiff!  It takes a lot more force to stretch it, so when stretched (tension or compression) it stores more energy and wants to recover faster.  If you put it in the middle of a bow where the fibers are not stretching, you would get little benefit except a cool racing stripe.  There is some merit to the stability argument, but the effects would be secondary based on engineering principles.

Since it is a stiffer material, it will transmit vibration better and absorb less energy.  The bow will get "twangier" as a result.  It is also more susceptable to mechanical damage and so often is made thicker than needed for strength purposes or coated in a layer of glass for protection.  Both options give up the benefit of achieving lower weight (although you still get the stiffness benefit.)

Just my two cents on your way to a dollar.

[canopyboy]

BTW, I do agree with everything that Pete said.

I will also say that I have never used carbon in building a bow nor have I shot a traditional bow that utilized it.  My moment on the soapbox is just based on it's use in the marine industry and other engineering applications.  Take it for what it's worth to you.

[Sixby]

I've been building carbon bows for over 8 years now. Until you learn its properties and how to take advantage of them it is a waste of your money. I would say it takes more than a few prototypes and some blown up bows to really get the lessons across and then there are even times you get on the phone and call your bowyer friends and discuss things. Carbon is really great if used properly and if you see the advantage if faster limb recovery , less shock , faster arrows. I see is as only part of the equasion , Number one being bow and limb design, two , tiller, tuning and timing. Two fast flight,. three carbon used properly.
When carbon is used in the core as several companys do it basicaly is being uses as a sales gimmic. It may  add a tiny bit of stability if it is a cross weave uni combination. However if used under glass and lamination you need a combination of glass and veneer around .040 to make it effective at all.
Another hint. Never place carbon directly on the belly. You may get by doing it on a long , long bow for a bit but it will eventually blow the lamination that is next to it or the glue line. When on the belly it needs a minimum of .025 glass over it.
I have found that when carbon is boxxed , a lam directly on the back and a lam near the belly it drasticaly increases the effectiveness. However it is also expensive. Therefor you must determine whether or not it is worth the money.
I believe it is. Others may differ.

God bless you all, Steve

[Pete W]

Not every Bowyer has had to give up trying to use carbon on the Back and  belly. There are some that have had good success.
 So much depends on the specific type of carbon, and the surounding laminations, and the limbs design.
 The Bowyer has his work cut out for him if he thinks it is a magic material.

[Dan Bonner]

I too chased the carbon phantom for some time. Blew up a ton of bows. I discovered that a glass bow that shoots in the high 180s fps and will last for years is my target vs a fragile carbon rig that may not last through my next hunting trip and is barely 5fps faster. I did get to know some cool folks in the aerospace industry though who would custom layup my lams so I guess it was not a total loss. Here is what I decided and this only goes for me: if ultimate speed is what I am after why am I building trad bows? Also you know how people find '50s model glass bows in old garages and attics and string them up and shoot them? That ain't likely to happen with your basic double carbon hot rod.

Bonner

[Sixby]

I don't know a bowyer that builds with carbon directly on the belly. Except longbows possibly and very few that do that if any.
Like I said it will overpower the lam next to it a blow the lam or the glueline. BTW some very respected bowyers Ihave talked to have told me that they discovered the same thing and no longer put carbon directly on the belly. One said that he replaced so many bows he thought he might have to go out of business;

Anyway just trying to save some people heartaches Pete.

God bless you all, Steve

[Pete W]

I agree steve that many have had dismal results, however some like Border seem to be doing just fine.

[Sixby]

Yes Pete they are doing just fine. Probably putting glass on over the carbon. Or adding glass directly to the carbon ect. BTW the last bow I had tested with a hooter shooter at 202 fps 28 in draw and 9gpp. That might compare even to Border. I don't hold up any manufacturer in awe including myself. I just use what I know to be fact to the best of my ability and with prayer . I also try to help those that have not had the experiences I have had that are bad so that they do not have the same. Some of these guys do not have the materials Border is using.

God bless you, Steve

[Pete W]

Steve , your experience is typical of most jumping on the carbon wagon. It is not the magic material many think it is, and not every type of carbon is suited for bows.
 It can be done, but few have had success,like Border has.
 By the way there is no glass at all in Borders limbs.    They do make up their own carbon laminates, rather than buying them. .

[fujimo]

i stand corrected.