In my last post I talked about all the things that go into a carbon frame. You have the carbon, the resins, the layup and so on. I also talked about the extent to which a manufacturer will go to insure safety and compliance of the finished products, which is a big deal. Let's deconstruct each of these elements.
Carbon Fiber: I am no engineer, but I know enough to tell you that there is not just one type of carbon fiber material. Much like aluminum or steel, carbon fiber has a myriad of grades and types. There are carbon fibers that have never been twisted, and there are some that have. There are different strand lengths, different weaves and so on. Take a look at this chart, which comes from a carbon factory in Alabama. Unless you are a highly skilled engineer you probably don't know how to apply any of these types of carbon to the production of a bicycle. Yes, the better bicycle manufacturers will use more than one type of carbon fiber in the layup of a bicycle. Why? So that the bike flexes where they want it and is stronger where it needs to be. Resin: Think of this as the glue that holds all the carbon fibers together in a sheet. It's also the glue that holds multiple sheets of carbon together. Did you know that resin's have a "best by" kind of date associated with them? Maybe you did. The point is that the resin that holds your carbon fiber bike together is just as critical as the carbon fibers themselves. Again I'm no engineer, but I do know that resins that sit to long and aren't kept in environmentally controlled conditions can lead to product integrity issues down the line. Hence, like a lot of things the resin's used in carbon need to be monitored throughout the supply chain.
Engineering: Composites engineers don't come cheap and many bicycle brands don't have the budgets to keep one on staff. The big brands like Trek, Specialized, Giant, Focus and some others certainly have among the best composite engineers money can buy on their staff. But, what about a smaller brand? Many smaller, credible brands certainly have engineers on staff that are fluent in the geometries and physics of a bicycle. So, what they do when engineering a carbon fiber bicycle is work closely with their manufacturing partners in Asia (maybe Eastern Europe) that have a composites engineer on staff. This is a pretty common practice and is more than acceptable.
The more reputable brands, those who might not have the volume of carbon bike sales to support a composites engineer, typically know what they want in terms of handling and comfort. So, they work closely with the engineers on the other end to create designs and layups that deliver the desired bike. Sometimes they'll create an entirely new bike (a mold) that has a proprietary shape to it. Sometimes they'll take an existing (off-the-shelf) mold the manufacturer has already developed and modify specific elements of the shape to make it more proprietary. Or they'll use an existing mold the manufacturer owns to save tooling costs, which add-up quickly when you consider all the frame sizes.
Here's where we go back to our Ford Mustang in the dark example. The shape of the thing does not always indicate the quality of the thing. Heck, Parlee's are boring to look at and it's conceivable that someone could make an incorrect judgement about their quality based on their "boring" shape. And they'd be wrong, right? It's not logical to conclude that if something looks "off-the-shelf" that it is somehow inferior in terms of its quality, workmanship and engineering. There are questions that need to be asked.
Compliance and Testing: People might assume that if a brand is selling a carbon bike frame or part that it must meet all applicable compliance regulations. Ok, which set of regulations are being followed and are they properly applied and interpreted for the specific product? There are European compliance standards, there are Asian compliance standards and there are US compliance standards. The European compliance standards are by far the toughest, but they don't cover everything and in some cases don't make sense for certain products. While developing the Whisky thru-axle disc road forks the engineer discovered that there were no guidelines for testing disc brakes within the road bike standards. Kind of makes sense. Until this year road bikes didn't have disc brakes.
So, what did the engineers at Whisky do to make sure their new fork was safe (and compliant)? First, they applied the mountain disc standard to the fork to make sure the lower part of the fork was strong enough. Second, they applied the road standards to the rest of the fork. The road standards are tougher than mountain. Don't ask... The point is that the engineers at Whisky could have tested to the road standard and called it a day. The fork would have passed and been compliant in accordance with the European standards they tested against. Remember this, compliance does not equal safety. The engineer at Whisky (Anna Schwinn. Yes, a legitimate Schwinn) demanded that fork be tested above and beyond the current standards to insure both compliance and safety. Smart!
So, who determines if a product is compliant? There are tests outlined in the compliance regulations, but how they are to be administered is subjective. Yes, subjective. More on that in tomorrow's post: Off-the-Shelf Carbon - Part 3.
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