How to tell if carbon fiber is real or fake

  • Categoria do post:Engenharia

Originally posted on my disable blog

Since carbon fiber products are synonymous with performance, luxury, and, especially, highly-priced stuff, it is expected that falsifications are going to pop everywhere. In fact, this is so true that a lot of people actually think that carbon fiber is just a type of wrap, as I had written in this article. So, nowadays know how to tell if a part is a fake or real carbon fiber is almost a mandatory skill. The kind of stuff that people should be taught in school.

However, it is not as hard as you may think to identify fakes because carbon fiber is a material with exclusive characteristics. There are almost no other materials out there that can be sincerely mistaken as carbon fiber. Especialy if we are talking about cheap stuff.

So, if you know exactly what is carbon fiber, and I had talked thoroughly about that in this article, to tell if a part is made of real or fake carbon fiber is really easy, even if you are only looking through the internet.

Here are some simple tests that will tell you the real story, almost for sure. If the part fails at any of those points below, you can assume almost a 100% probability of being a fake.

1. Knocking

For sure, the number one way to tell if carbon fiber is real or fake is to knock it. Your indicator finger knuckle is the best carbon fiber probe in the world.

The most important properties of carbon fiber are that it is a light and extremely rigid plastic. So, when you knock it must feel like a very thin, hollow plastic part.

On the other hand, fake parts are always made the same way. They are some cheap plastic or metal parts wrapped in some kind of carbon fiber-mimicking sticker. If, however, it sounds metallic, or heavy, or solid you know you are dealing with a fake.

If you are not sure how real carbon fiber knocking feel, go to the nearest place where carbon fiber is abundant: the high-end bike shops. Find some cool top-notch road bikes and start knocking the frames, you are going to develop the feel immediately.

2. Real carbon fiber has a 3D feel

Real carbon fiber parts are made out of carbon fabric embedded into epoxy resin. If you are about to test a clear-coated part, the fabric fibers must be apparent. In fact, almost all fake carbon fiber parts are made to cosmetically resemble carbon fiber, so the probability of finding a painted fake carbon fiber part is much smaller.

So, a quick and easy way to tell if a carbon fiber part is fake or real is to see if the fabric looks embedded into a glassy matrix. The epoxy resin, most of the time, is super clear, so the fiber inside it will have a 3D, deep feel to it. Carbon fiber has depth to it, so the last layer may have a thickness of about 0.2 mm, which is quite deep to the eye and you can see the fibers weaving into the fabric.

Since fake parts are almost always something covered in a wrap, it will always look shallow and 2D because the wrap is just a printed pattern with a thin cover of a clear coat. So, if it looks shallow, run away. One quick trick is to scratch your nail on the surface. Real carbon fiber is completely smooth, while in some fakes you can feel the texture.

Again, the best way to learn this skill is seeing the real thing by yourself, and the bike shop is the easiest place to find high-end carbon fiber stuff.

3. Pattern joining

I had already explained in this article that carbon fiber parts are made by stacking several layers of fabric on a mold. However, a piece of fabric cannot accommodate all the curves of a complex part, so it must be cut and joined by fabric coming from different directions to accommodate the part shape.

This process results in clear fabric pattern misalignement that is inerent to the material. However, the bad news is that the same thing happens when wrapping the part with a vinil. The difference is that in the real carbon fiber part you can tell the fabric joinings are embedded deep into the resin, while in the fake it will be superficial.

Also, since carbon fiber is stiff, the fabric pattern can’t be stretched or deformed. Vynil wraps, however, can. So, if ou see stretched patterns or superficial joinings, you know you are probably dealing with a fake.

4. Look underneath

However, if you are dealing with a painted part and it passed through the knocking test, it doesn’t mean you are all clear. Sometimes, people paint fiberglass to make it look like painted carbon fiber. As a matter of fact, painted fiberglass will look much like real carbon fiber and, if it is thin enough, knocking may give you a wrong impression.

In those cases, most doubts can be eliminated by looking underneath the part. Real carbon fiber parts will always be better finished, even on the opposing side of the mold. This is due to the vacuum process used in fabrication that creates a smoother surface at the back. A rough surface underneath a hood (or bonnet for UK folks) is almost a definitive indicator of a false claim.

5. Lightness

The real biggest difference between carbon fiber and fiberglass is the weight. Fiberglass is way heavier than real carbon fiber and, most of time, way thicker, too. That’s why most of fiberglass parts can be detected using the knocking test.

But, sometimes, they are so well made that it can pass through. So, a good way to tell if a part is made of real carbon fiber, is to feel its weight. Since carbon fiber has a low density, those parts will almost always feel much lighter than they look. Fiberglass, on the other hand, can be even heavier than steel. Carbon fiber is surprisingly light, literally. Lift a real part and you will feel it. Again, bike shops are good friends.

It doesn’t mean that there aren’t heavy carbon fiber parts. But if it looks heavy to you, it is safe to assume that you are looking to a low quality part. Carbon fiber requires expertize to be made. So, run away from low quality parts, even if they look like real carbon.

6. Stiffness

One of the most important features of carbon fiber is its stiffness. So, since fakes are mostly cheap plastic with a carbon fake wrap, you may not expect the same stiffnes from them.

Particularly thin plastic fakes will deform when you press it with your thumb. Real carbon fiber surfaces are so stiff that you can’t compress them without a good amount of force. So, if it flexes, you now it is fake, or in the best scenario, bad engineered.

For illustration, some car body parts, like fenders and rear quarters can flex quite a bit if you push them. If they are made of carbon part, it won’t be that easy. That’s why carbon fiber is a favorite for aeronautical parts.

7. There isn’t colored carbon fiber

You can easily find colored fake carbon fiber wraps on eBay and Alibaba. Althought they look much cooler than regular black fiber, a real carbon fiber part can’t be colored.

Fake colored carbon fiber. That one is easy to spot from a mile!

The reason is that the color of the fibers are due to the characteristic color of graphitic materials, and it can’t be tinted. So, if you spot some colored carbon fiber part, they are totally fake, for sure.

8. Always buy from reputable companies

For sure, the best way to avoid fake carbon fiber parts is to buy from real people. A reputable company will always make sure your part has good quality.

There are several videos on Youtube of people with cheap carbon bikes from China. They claim those factories are the same that make the best brand bikes, but it is just a scam. Those bikes are so soft that sometimes they flex only with the weight of the rider’s body.

The reason is that a lot of carbon fiber engineering deals with the orientation of the fabric layers since it is an anisotropic material. This means it deals with loads according to the direction they are applied. If the part is poorly engineered, it won’t be as strong as it would be in some directions, causing it to flex.

So, you can buy the real carbon fiber material, but with fake engineering. This is as bad as a fully fake part and can be really dangerous. A rider’s life may rely on the strength of a carbon fork, for example. Even if it is real carbon, fake engineering can put you in real, real trouble.

As a rule, and since carbon fiber is a composite material, real carbon fiber is not just about the material itself, but about the engineering involved which could, of course, be fake. Avoid fake engineering at all costs.

Sometimes it is ok to be fake

As a closing paragraph, I must say that not always fake carbon fiber is bad. For example, some cheap scooters, motorcycles, or cars may have fake carbon parts for decoration.

Especially on cheap motorcycles, a carbon fiber fairing won’t really improve its performance. Along with that, the cost of repairing a broken real carbon part after a crash will be spectacularly higher than a plastic fake one.

I would say that fake carbon must be avoided for structural parts, but decoratives are ok as long as the seller asks a fair price.

All that said, I hope that now you can tell if a carbon fiber part is real or fake. See you soon!

Fábio Ardito

Pelo mundo atrás de treta.

Deixe um comentário