I know lot about carbon fiber. I own and run a business designing and hands-on fabricating carbon fiber components and products for aerospace/defense, top motorsports teams, UAV/Drones, sporting goods and more. (started this 12yrs ago after one of the software companies I co-founded sold).
I was a competitive cyclist and still Mtn Bike a lot and race occasionally. Obviously, I think carbon components are fantastic. I could make my own, but I do not.
Here's why:
ENGINEERED MATERIALS: Carbon Fiber composites are an engineered material. This is great because the strength is very specific, and we can put the strength exactly where we need it, and omit the strength -and the weight- where it is not needed.
This also means that the materials MUST be properly engineered to yield acceptable performance. This is NOT just fancy plastic or "black aluminum".
Get the engineering right, and you have amazing parts that are both stronger and lighter than steel or aluminum. It is not unusual for us to outperform an aluminum product with a 40-50% weight savings and higher strength numbers.
BUT, get the engineering wrong, and a carbon part that looks massively overbuilt, thicker and heavier than the equivalent steel part, will fail catastrophically.
Moreover, there are THOUSANDS of combinations of grades of carbon fibers and epoxies, all appropriate for different applications, and these must also be properly selected.
So, even if you obtain the exact molds used by Specalized to make their frame, without knowing the exact materials and design, it would be very difficult to make a frame that performed properly.
FABRICATION PROCESS: The fabrication process is critical. - Everything must be cleaned properly. - Every single one of the hundreds of pieces of carbon fiber must be cut properly, then placed properly in the mold, in the correct sequence, and the correct orientation. - The mold components and compression tools must be placed properly and achieve and maintain the designed pressures. - The heat and cooling cycle must be applied properly. - The demolding must occur properly. - Any post-cure cycling must occur properly. - Any secondary bonding must be prepared and executed properly.
Any failure in these hundreds of steps, and the frame will have a flaw that can hurt of kill someone. (not that it necessarily will, but it easily could -- simply consider hitting bumps in a fast descent -- that will be the exact point of maximum load, most likely to cause failure, and now the cyclist is Wyle E. Coyote... not fun).
The fabrication process is analogous to having to ship software where we cannot make an error-corrected perfect digital copy, but each new copy must be hand-transcribed before shipping, and of course cannot be destructively tested. How well would you trust bootleg software running your heart pacemaker if it had to be copied the way monks copied bibles in the middle ages?
TESTING PROCESS: Both the engineering design and the fabrication process must be subjected to rigorous testing.
On the engineering side, even the most sophisticated modeling software needs real-world test validation of even basic parts models, as the number of variables is huge, and an initial design often does not yield the expected results.
On the production side, every step of the process must be carefully designed, and verified to accurately and repeatedly produce parts that perform as engineered.
BOTTOM LINE: This is obviously just skimming the surface, but the bottom line is that there are hundreds of opportunities for failures to creep in even when trying to do it right, and ridiculous opportunities for counterfeiters to cut corners. And most of them will NOT be readily visible to casual inspection of the product.
I could, with my knowledge and access to my own shop, make a pair of carbon fiber handlebars to ride tomorrow. But I wouldn't ride them further than around the parking lot. We'd need to make a big investment in designing then fabricating and testing scores of units before having the confidence to take one for a real ride.
But, standing in the shoes of a desperate counterfeiter in China, where ripping-off IP is the ethical norm, and who will be selling parts to unseen and probably despised customers on the other side of the globe, and who probably doesn't understand enough about the engineering pitfalls anyway ... ... sure, just copy some molds, buy any old carbon, and start slapping it in and cooking it, just make sure it looks good.
I've seen even legit parts come in from Asia with crazy shortcuts, never mind the counterfeit stuff. I've also personally witnessed those parts causing disasters.
As a rider, just seeing this crap coming into the US is truly frightening. Even the legit parts are cause for worry -- are the US guys actually riding herd on the Chinese QC well enough? Probably.
The counterfeit or low-market stuff? Forget it -- you literally couldn't pay me enough to ride it anywhere further than across the parking lot. Anyone who considers doing so is really ignorant of the real risks.
It's just physics, and physics does not care about you.