Scott Advert Offers a Detailed View of the Carbon Fiber Manufacturing Process

Mar 13, 2013 at 0:07
Mar 13, 2013
by Richard Cunningham  
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Scott's Genius 700 SL: 650B trailbike sports an HMX carbon front-section
Scott Sports' Carbon Process Revealed

Scott Sports assembled a video-pictorial documentary of its carbon fiber manufacturing that gives much insight to the process. Many of the steps that Scott uses to produce its carbon frames are similar to those used by other top frame makers, but everything you'll see in the advertorial is pretty much as good as it gets. Scott speaks of two high-modulus carbon fiber materials, HMF and HMX, and both are its trade names. The actual brands of the high-strength carbon that Scott uses to build its elite frames may remain secret, but their improbable weights and successes in World Cup competition cannot be denied. Photos in the following editorial are excerpts from the Scott story - it's well worth a look. - RC

Scott begins like all good bike makers: with a goal, a team of experienced engineers, an expensive computer composite modeling program and perhaps most valuable, a history of elite-level composite bicycle construction. Once the frame has been designed in digital form and each of the many carbon layers and fiber orientation has been worked out, over 200 shapes are sliced from rolls of pre-impregnated uni-directional carbon on a computerized cutting machine. Some are as small as postage stamps, others, large enough to wrap around the entire length of a tube.

Molded 'bladders' maintain the shape of the frame-to-be. Assemblers will cover the bladder with carbon swatches in a precise 'layup schedule.' The impregnated resin causes the carbon to stick to itself. Later, when the layup is placed in a mold, the bladder will be inflated to compress the layers evenly together while the resin becomes liquid as it is heated and cured.

The frame layup is placed into a steel mold. Once the mold halves are joined, the bladder is inflated and the mold is squeezed between two heated plates for a specific curing cycle. The rate that the mold is heated and cooled, and the exact temperature is critical. While some carbon frames can be molded in one piece, the lightest ones are usually molded in smaller sections and then mated together in a final curing process.

Before the design is finalized and periodically during production, finished frames are tested to rigorous international standards for fatigue and ultimate strength. Scott tests its frames to a higher standard to ensure a generous safety margin.

Frames may require minor machining at the bottom brackets, axles and pivot bosses, and all need some sanding and prep work, but for the most part they emerge from the mold in a semi-finished state, perfectly aligned and at full strength.

Watch the video and read full story about Scott's remarkable carbon fiber manufacturing process.
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  • + 5
 The majority of people know how modern carbon frames are made. I would like to see the manufacturers put out videos of them testing frames after wear and tear has been put on the frame and components to get rid of the carbon = fragile mindset, that is if its not true....
  • + 6
 I want to see fatigue tests with frames that have scrapes, scratchs, nick, gouges, and rock impacts on the frame.
  • + 13
 Watch the video. That's exactly what is going on as a lot of the frames are previously used.
  • + 12
 If you bothered to read the article you would find out that the carbon frame they tested was previously ridden so I would be willing to bet it had scratches and chips:

"This particular Nomad Carbon has already seen its fair share of abuse, having been through 200,000 cycles of fatigue testing, two different impact test scenarios, and then ridden hard for two years by a Santa Cruz employee."
  • + 2
 Besides the tests on fatigue, it'd be cool to get a comparison on the waste produced in the various production methods... Anyone know how that bladder is removed? I know in some production it's left inside but sometimes it's dissolved out with chemicals.
Also, how recyclable is all the scrap? Before someone jumps on me, I dig carbon fibre as a structural material but it seems alloy frames are infinitely more recyclable... Does the world really need more plastic?
Nice looking bikes btw.
  • - 2
 i think easton has a technology of using nano tubes to increase the strength of their carbon bars. and these tubes have about the same size as asbestos dust, leeding to some people saying this will lead to the same problem as with asbestos. however, i don't think it is really recyclable... but nonetheless a material i definitely would like to have my bike built with.
  • + 3
 This is a topic I would like to see a definitive article on. Currently I’m of the impression carbon fibre does share properties with asbestos, but they only seem to go as far as to say carbon fibre (dust) is an irritant to the skin, eyes and lungs, though I can not understand how it can not be more hazardous than this if it has the same particle sizes as asbestos. There are huge Health and Safety implications, what about all those who cut carbon steerers/bars/posts. Should a bike shop provide ‘clean room’ environments? What happens to old carbon frames/components?
Not very ‘Green’ is it?
  • + 2
 It's common practice to do fatigue testing on carbon and aluminum parts these days. I think Easton has some video of that. Carbon is NOT known for failing due to fatigue, where aluminum IS. Carbon can be flexed and flexed and flexed, as long as it's flexed less than it's breaking point, it doesn't fatigue. Aluminum fatigues/degrades as it flexes, thereby has a set life. Ali parts that don't flex much would have almost indefinite lifespan also to be fair.
I remember reading an article a few years ago about a company that recycles carbon fibre, so it can be done. Lots of people harp on carbon as environmentally unfriendly. I disagree, it lasts longer, thereby offsetting the manufacture of replacements. No one seems to have done a scientific comparison of the embodied energy between carbon vs aluminum, but I wouldn't be surprised if carbon came out ahead. Aluminum production is heavily resource intensive.
  • + 2
 Its worse than you think. Matrix breaks, nanoparticles and chemicals that harm reproductive systems of everything leaching into environment. Incinerating not good either. Stuff stays forever. Definitely not the material for consumables like cars, bikes, planes.

One of the reasons carbon frames are painted is that you shouldn`t touch epoxiresin with bare hands - even when cured. Its bad stuff. We built surfboards out of epoxi. If your respirator didn`t seal well - you would know immediatly.

Bikes are such a good example where everything can be made 90% out of recyable materials, steel and aluminum.
  • + 4
 Wakaba.. You should tell that to Enve who donot add any finishing to their rims after being removed from the mold.

If you are going to be postings these "facts", you should be backing them up with msds safety sheets or studies of these hazardous materials.
  • + 4
 Production energy

aluminum -155 mj/kg

Steel -20.1 mj/kg

Carbon fiber 5-30MJ/kg.

looks like carbon fiber is the clear winner to me, with aluminum taking the worst toll on the environment
  • + 2
 @manuesi if you believe nano tubes are being used in your Easton bars and you can get them from CRC for under $190, then you are sadly mistaken, my friend.

Paint is also used to prevent UV damage, as the epoxy is sensitive to degradation from UV.
  • + 1
 @Terrafire. then what does the CNT stand for ? Easton Monkeylite CNT

@foghorn. your statement still does not justify carbon if it is carcinogenic

Keep it real... Feel the steel
  • + 2
 Interesting foghorn, I was always under the impression carbon fibre production was absurdly intensive. Where'd you get the figures?
It's always complicated to quantify the true cost of processes that are so involved and that's just to get the raw material...
That carbon fibre has to be processed further to produce the pre-preg fabric which brings into the equation another product, how clean is resin production? Again, the stuff has incredible properties, but at what cost?
  • + 5
 CNT stands for marketing
  • + 1
 Btw, to interpret your figures correctly, what is the weight comparison of cf vs al in a bike. (Not cf and resin)
  • + 2

This stuff is really, really bad.

All of them can and will leach, some turn very very toxic.
  • - 1
 Most of us are using computers that feed from nuclear power plants to surf on Pinkbike daily. Yet -oh no!- carbon bike parts are made with toxic components. Really...? What's happening? Are we all going hippy on this? Just ride your bikes and don't think this much. Oh and respect your bikes, because bad maintenance means more wear and a quicker need for parts replacement; parts that cost energy to manufacture.

  • + 3
 Ignorance is bliss?
Hey it's just a conversation Robby, I've heard some interesting responses to the question. Environmental responsibility comes from some unlikely places... Hypocritical perhaps, but awareness is a step ahead. Even your perspective on good maintenance is a good one. It's not hippy to care about our impact. Yeh you only live once but we also only get one earth.
Btw my tablet runs on love man...

  • + 2
 One of the Nomad frames in that video had, if I remember correctly, over 1000 miles on it.
  • + 1
 @foghorn1 Are all those in milijoules(mJ) or megajoules(MJ)? If you listed those correctly then steel is the most efficient at 20.1 microjoules.
  • + 2
 Carbon is very, very strong in the direction it is designed to be loaded. That is what those drop tests in the video measure.
  • + 2
 @wakaba MEKP is not used with epoxy...this is an article about bikes, not surfboards. Wink
  • - 1
 No, Silocycle... Ignorence is not bliss. The situation is hypocritical. People know so much better than they handle right now. We could be so much further regarding the environment, but money is central in our system... Money = power. Since knowledge isn't power, I refuse to think deeply for the environment when SUV's and sportscars are still on the streets. If we would change something about the environment and reduce our carbon footprint (hehe funny, 'carbon' footprint...) everyone would benefit from that small change, even those who don't want to commit and keep consuming like idiots.. I know a lot and learn more each day, because I have something against weakminded people... But we alone, we cyclists, can't do enough. Everyone needs to help "saving" Earth. So meh... I will not put any more effort in this [bikewise] other than cleaning and maintaining my bike, and ofcourse riding it...
  • + 2
 @Silocycle. I did a websearch on the various materials ali and steel figures came from wikipedia, carbon fiber was the hardest figure to find, but found a forum post that looked pretty credible. Sadly the source link was rotten.
@Ride-more, You are more likely to get cancer from a cell phone or using your laptop on your lap than from what off gasses from your carbon bike.
@deadlymailman. All of the figures should be in megajoules, My bad for messing up the capitols. Steel uses roughly seven times less pound for pound than ali, offset by need for more pounds per bike, So I'm guessing between 3 and 4 times less energy than ali per frame? Carbon fiber frame is going to weigh much less than a steel frame, so with similar amounts of energy to produce , carbon FTW.
@Wakaba, Stop eating BPA will ya? Or at least switch to certified organic BPA like I did.
  • + 1
 All I have to say is resin, resin, resin and resin.
Is that not what usually fails?
Is that not he highest consumable in its production?
I s that not the largest environmental impact?
So what happens to all these carbon frames once they are broken or discarded?
I have yet to see anywhere to drop it off for recycling!
No it ends up tossed or dumped in landfills!
So how long does it take to breakdown?
What happens to all the chemicals in the resin?
Do they turn into something toxic as they breakdown?

You are all missing the fact that 99% of all our bikes are manufactured in countries with next to no labor laws to protect workers. Almost no Environmental laws or anyone to(or is willing to) enforce the ones they do have if someone in the government is getting paid off. Then they are put on container ships belching out ton's of pollutants to be shipped to ports in your countries and then on to more Diesel or Gas burning, oil lubricated, petroleum byproduct synthetic rubberized transportation to end up at your Local Bike Shop.

What really needs to happen is more centralized local Manufacturing of ALL bicycle frames that would increase your local and regional economy and cut down on shipping pollutants While giving, those countries that have them, the ability to enforce Environmental and labor laws!

But then we would be paying double or triple the price for are beloved Mountain Bikes and we can't have that now can we!
  • + 2
 Specialized has a Carbon Fiber recycling program. Seriously. Google it before you ramble on the internet.
  • + 1
 @ Terrafire- That would be great if it was used and its got to be "participating Specialized dealers"! Not every city has a Dealer, not everyone knows about there program and their dealer may no participate. Our local dealer says nothing about it and I live in tree hugger central! I will go ask them if they do tomorrow.
I have yet to see one broken carbon frame get recycled. I have seen countless carbon frames get thrown into dumpsters destined for the landfill. I have also seen a carbon manufacturer toss defects into the garbage.
So I will continue to ramble on the f*cking internet!
You still have yet to Google me a way around every other point I tried to get across so by all means internet King please please enlighten me on the problems of overseas manufacturing.
  • + 1

this is how Carbon Fibre should be cut in a professional bike workshop:

-always a new hacksaw blade with high TPI count, masking tape around the cut will prevent fraying whilst cutting
-ask other mechanics to leave the workshop
-air extraction system on full power
-disposable cloth laid under cutting guide to catch dust / particles
-cloth damped down with water or solution of mild detergent
-PPE includes dust particle mask, apron, glasses and gloves.
-finishing after cutting using fine grit abrasive paper to smooth the CF internally and externally.

-after cutting, carefully wash dust off cutting guide using soapy water into dustbin bag
-wipe down vice and bench with wet cloth and put into bin bag, along with hacksaw blade, gloves, mask, cutting cloth and grit paper, along with the CF length you have cut off
-seal bag carefully as to not kick up dust from the bag.

recycling? no idea...but primarily you need to maintain you own H&S in the workshop environment
  • + 1
 So today I spent approx. 30min making phone calls so I would have answers for my fellow locals riders. In my area I could not find one shop (including Specialized dealer) or recycling center that handles carbon fiber. On the other hand there are 4 drop off centers for steel or aluminum and I found 10 private people who will come or meet me to pick it up for recycling.

Again my biggest concern with ANY material bicycle frames are made out of is the fact its made overseas in countries with little or no laws to protect workers or the environment and all the transportation pollutants that go along with that.
  • + 2
 Foghorn how can you say that something measured in megajoules is better for the environment than something measured in millijoules? Energy is not the complete life cycle analysis. Bike magazine did an article on how green bikes were and steel is best aluminium next best (precious metal al alloys next I reckon though not reported) then Ti then carbon last. We need Hemp composites for greener bikes with naturally derived resins.
  • + 1
 This is awesome dudes! Nissmo, kickass man. I hear your point about the off shore issues. One of the things that turned me on to Devinci was the fact that the Al comes from across the road! But they are into the carbon game too and making some pretty wicked bikes out of it. It's hard to have an opinion without all the facts and pretty easy to convince myself one way or the other. I've built some pretty cool stuff with composites and I usually justify it by telling myself I'll take care of it and keep it for a long time. Not sure that's enough though...
  • + 1
 Hello Hampsteadbandit, Your measures are valiant though in my humble opinion are futile. The dust is so fine it becomes instantly airborne contaminating everything. (if i was you i would cut it outside) With a construction background I can tell you if it was asbestos H&S would shut you down.
More to the point, and of course of no surprise is that no manufacturer (who are no doubt reading this) will take up the carcinogenic question, wish I’d put it to Easton the other day.
  • + 1

the fineness of the dust is why we damp the cutting surface and saturate the work whilst its being cut

we end up with a lot of dust trapped on the cloth, which goes into the bin Wink
  • + 1
 Choppertank3e They are all megajoules. I screwed up not paying attention to the capitols. Not that i've read the article, Re Bike magazine, I don't believe everything I read, sometimes trust my own research more... I'm absolutely impartial.
  • + 1
 Any idea what software program the designer is using, in that first photo? Looks vaguely like Pro/Engineer. I was wondering if there was a program or plug-in that let the engineers include carbon layup schedules in the CAD model, and then do FEA on those models.
  • + 1
 Saw the Vid. : RC is this thermoplastic carbon fiber? I noticed the tubes are bonded together.
This is not a monocoque frame. I personely dont trust bonded frames. I dont think you can predict the angle of flex on a bike frame do to the unlimited variables on how a bike is ridden. Some peeps can land a jump on a crazy side angle. Testing in a lab cant replicate all the different loads applied to a bike frame.
Monocoque frames are a safer bet.
  • + 1
 No. Thermoplastic construction usually refers to when the carbon is premixed with a resin that can be melted with heat and then laid up in a similar two piece mold as a conventional carbon frame. Inside the mold, the heated plastic melts and mixes under pressure, and when the plastic cools, the part becomes a single piece. The melted resin can also be injected into the mold to impregnate dry carbon fibers - or mixed with short, chopped fibers and then injection-molded to make a final part. In every case, however, the resin that bonds to the fiber matrix is basically unchanged after it is melted and cooled (like wax).

Most carbon parts are made from two-component resins that when mixed together, go through a catalyzation process that results in a third, much stronger material that cannot be reversed into its original components simply by melting it.
  • + 1
 So the two part resin would be Epoxy which has the greatest strength compared to other glues. Plastic sounds cheesy but i can remember Polimar making engine blocks out of the stuff. Thank you for your reply Richard.
  • + 1
 Innovation?? I used to own a GT STS DH circa 1998! It snapped...badly!.......Once bitten twice shy as we say in the uk. never had a steel or aluminium frame snap on me, bend and dent but not snap......oh and I'm not your brother!
  • + 2
 I like the article but I'm pretty sure most people on this site know how carbon fiber bikes are made... anyway like the paint jobs on scott bikes, the matte black is sick
  • + 0
 Well, know well enough for their uses. Anything proprietary will definitely stay that way.
  • + 2
 I don't. How do you get the bladder out?
  • + 4
 Ooo-eer those bladders look a bit intestinal...
  • + 4
 When will we see the gambler in carbon?
Now that will be SICK!!!
  • + 3
 Probably working on it now, they had to get the alu version spot on first as it considerably cheaper to rework the design of a prototype alu frame than make a whole new mold for a carbon proto, to make small changes that are constantly made when the frame is in proto stage.
  • + 4
 Nothing beats a steel frame for mountain bikes.
  • + 3
 So how do they get the bladder out of the frame or is it always in there?
  • + 1
 I'd be surprised if it stays in for the weight factor. Maybe the frames get dunked and its dissolved, maybe you can just rip it out...
  • + 1
 Did trans Rockies 7 day xc ride in bc last year and saw at least 4 squashed Scott carbon frames.... All the euros were on em. Coincidence, or correlation?
  • + 1
 love this products,looking for a new ver in carbon
  • + 0
 Let me guess: The video shows footage of an engineer manipulating a 3D object on a computer screen. That's not clichéd at all.
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