Tech Speak: Talking TeXtreme Spread Tow Carbon With Oxeon and Felt
Often, if you want to see the pinnacle of carbon fiber design, you need simply look toward Formula 1. Teams invest millions to build the fastest, lightest, most aerodynamic cars which are able to withstand speeds of 200+ mph and remain strong enough to protect the driver in a crash. Over the past few years all of the championships have been won using Oxeon’s TeXtreme spread tow carbon fabric, though F1 is a small part of Oxeon’s success.
2013 saw the introduction of TeXtreme to the bicycle industry with Felt’s first use of the incredible fabric in the launch of their FRD line. Since then, Felt has introduced 4 new models that also get the special checkerboard look, which prompted us to sit down with David Kolosek of Oxeon to get a better understanding of what sets TeXtreme apart from “everyday” carbon.
Oxeon weaves us a story after the break.
Bikerumor: What is Oxeon’s and TeXtreme’s history in carbon fiber?
Oxeon: Oxeon is 10 years old now, the company is based in Sweden, and two of the original founders are still with the company and they were students at the university in Gothenburg, Sweden. They were part of the entrepreneurialship program where they the students with the ideas were paired with professors who helped take the ideas to market. Originally, the company didn’t start out as carbon fiber based, but more of a weaving process and here we are 10 years later with the weaving process.
If you look at the supply chain of carbon fiber products if you will, in the beginning you have the fiber manufacturers who actually make the carbon fiber. The fiber is then moved to a converter – someone who actually does something with that fiber. We’re a converter. We take what’s called a bobbin, which looks essentially like a bobbin of thread, which they call “tows”. A Tow is essentially a carbon fiber yarn, and those yarns have anywhere from a 1000 to 30,000 little filaments inside. Each little hair in carbon fiber is a filament. So we take yarns that typically have 12,000, 15,000 filaments in them, and we spread them.
We have a process that takes that yarn and makes it into a tape like you have here (above left). Compared to a traditional unidirectional carbon, our carbon tape is able to be produced much thinner than the unidirectional carbon. They might both be made from 15k filament, but we’re able to spread it over a wider area, so we have a lighter weight for the same given surface area. We then take these tapes and we weave them into fabrics. This is called a TeXtreme fabric, TeXtreme is the brand name of our carbon fiber fabric.
Compared to a plain weave, every where you see the white space on a traditional weave carbon is resin. When the carbon fiber goes up and comes back down that’s called a crimp. When it changes direction, it causes a gap to the fiber going 90 degrees the opposite direction. In order for it to be flat, that piece has to be filled with resin – it’s why when you look at a traditional sheet of single layer carbon your can see light through it. When you hold ours up to the light, there is barely any light that shines through. That’s because for the same area, the same size, you have a lot less resin that is needed with our spread tow carbon compared to standard carbon which results in a much lighter weight. You’ll have more carbon fiber per area than with a traditional weave, and keeping those fibers as straight as possible improves the strength. Because our design has shallower and fewer crimps, we’re able to build in the same directional strength with less carbon.
Bikerumor: Could you build a whole bike out of TeXtreme?
Oxeon: You could, but you probably don’t want to because there are going to be areas where you only want more stiffness or strength in one direction, not another.
Bikerumor: Is there more than one version of TeXtreme fabric?
Oxeon: Yes, TeXtreme can be produced with HS, IM and HM carbon, along with many other high performance fabrics. Also, there is what you call 0/90°, where one carbon is running in 0 degrees and the other is running at 90° to it. That’s going to give you strength lengthwise, and in the circumference, but what you give up is torsional strength. So the way that engineers overcome that is they rotate it so it’s +/- 45°, you have one running at 45° going one way, and the other at 45° the other way. That gives you the torsional strength. If you built it entirely out of +/- 45° you wouldn’t be able to twist it, you would have great torsional strength, but you would be able to bend it. So good design is a combination of the two for proper stiffness and strength all around.
Bikerumor: So some areas of the bike may have a layer of 0/90° and then a layer of +/- 45° on top?
Oxeon: Correct, depending on where that area of the bike is there may be +/- 45°, there may be 0/90°, or it may just call for unidirectional carbon. The number of plies may vary, there may be as many as 4 plies, plies being a layer, there might be as high as 8 plies, depending on where it is in the whole make up of the frame.
Bikerumor: How does TeXtreme improve bicycle design?
Oxeon: What’s great about the product for designers like Jeff at Felt, a lot of what he’s looking for with the FRD bikes is feel, comfort, and ride quality. Because of the weight savings that he can accomplish through the use of TeXtreme in certain areas, he’s able to take some of that weight saved, and redistribute material into areas that stand to improve the overall ride quality of the bike.
Bikerumor: When you look closely at you Spread Tow fabric, what are the swirls you see on the carbon filaments?
Oxeon: Those swirls are a patented, proprietary element which act as a binder agent. We take that binder and we put it on the tapes which helps to keep all the fibers together, which in turn helps keep the fabric together. That means in the factory when they’re building the frames, the fabric is much easier to work with. If it didn’t have this binder, it would want to come apart. If you’ve ever gotten a snag in a sweater, if you could imagine it would sort of be the same thing with the carbon if the binder wasn’t there to keep all of the individual filaments in place during manufacturing.
Bikerumor: Is Felt the only bike company using your carbon for frames? (The answer to this question has changed since the time of the interview – Kemo bikes has introduced a frame using TeXtreme, and it wasn’t a frame but Shimano PRO athletes raced on a TeXtreme equipped Disc wheel in the Tour de France.)
Oxeon: At the moment, yes, Felt is the only bicycle company using TeXtreme. We do not have an exclusive with them, but Felt was one of the early adopters and they’ve been great to work with. Last year they had one model, and this year they have 5 models now. This sends a great message to the industry about our product, and at retail gives them something truly unique in carbon technology.
There is also the unique look to the carbon, though the cosmetic is really just an added bonus, with the most important aspect being the performance of the fabric and what the fabric does.
Bikerumor: Does spread tow carbon fabric open the possibilities for future frame design?
Oxeon: Sure. We certainly think so due to the fact that since our carbon allows quite a bit of weight to be removed from certain sections of the bike while still retaining the strength, it really allows you to tailor the frame design to individual styles of riders to make a better performing bike.