“Black aluminum” is a term used in the aerospace industry to describe composite structures or components that are not optimized for the material and process. Essentially, it refers to taking an existing aluminum component, and making the exact same design out of a carbon fiber composite. In the end, the only visual difference between the two components is color and cost. In reality, a composite structure should look entirely different from its metallic counterpart, due to the anisotropic material properties and different manufacturing methods. Carbon fiber is extremely strong in tension, along the direction of the fibers. However, transverse properties can be weaker than many types of plastic. But properly designed and manufactured carbon structures exceed the strength of steel, at less than half the weight. It’s an amazing material, capable of being formed using a number of interesting manufacturing processes.
To this day I still have vivid memories browsing the various bike magazines and catalogues that arrived in the mail for my dad. I’ve always been interested in carbon fiber, especially after seeing the Trek Y-33 mountain bike for the first time. The full suspension frame looked so exotic, but also introduced a new level of functionality as full suspension bikes were still very rare. Enabled by a transition in materials and processes from welded metals to oven cured resin and fibers, the Y-series frames were one of the earliest examples of engineers rethinking how to design and manufacture one of our oldest inventions for a new material. I didn’t understand at the time, but the Y-33 was the first non black-aluminum frame design. Instead of lugged composite tubes, the Y-33 was molded as a single monocoque structure. It was an early inspiration for not just Project Cedrus, but my career thus far.
Coincidentally, Pinkbike recently released a great story on the suspension technology used in the Trek Y series bikes, which wasn’t as progressive as the structural advancements. I hope you don’t mind me sharing your photo Richard, thanks for the history lesson!
My interest in composites never faded, and and by the time I was finally able to afford my own Trek Y-bike, the technology was far out dated. But as these new materials continued to find their way into skis, bikes, sailboats, and airplanes, I knew I wanted to study engineering with a concentration in solid mechanics and composite materials. After graduating in 2006, I returned to my home city of Seattle for a job with Boeing on the first carbon fiber commercial aircraft. After 5 amazing years and delivering the 787, my dream of Silicon Valley came true as opportunities [and financing] arose building UAVs and flying cars. Realizing the regulatory hurdles for electric propulsion and pilotless planes, I decided to transition to consumer products with Apple and learn how to design and manufacture things with some of the best engineers in the world. After a few challenging but rewarding years there, introducing some of the first structural composite components in Apple products, I felt ready to start my own company in mid 2016 to offer consulting services and pursue personal projects. I’d always loved sporting equipment, especially bikes and kites, but iPads and Airplanes have always paid the bills. So shortly after getting my first consulting gig, and some income to pay for the various software licenses, I began to put my ideas to [digital] paper and filed a provisional patent for some of the key design aspects of my hydrofoil.
The carbon foils on the market today are heavier, more expensive, less damage tolerant, and more environmentally destructive than their aluminum counterparts. The only obvious advantage of today’s carbon mast is valued by racers; the higher specific stiffness material allows for a thinner section (with less drag) when the mast is fabricated from a solid laminate at near weight parity to aluminum. Composites do provide improved damping characteristics over metallic structures, but unless your primary objective is speed, there’s little reason to pay the premium for a carbon mast. My motivation was simply to change this paradox, and to engineer the first non black aluminum composite foil.
The primary goal was to reduce weight and material usage. I don’t remember when I first heard the phrase “weight is the enemy of everything,” but it’s true on many levels. With carbon fiber being 40% less dense than aluminum (1.6 g/cc vs. 2.7), having twice the stiffness (120MPa smeared vs. 68) and more than 10 times stronger (4,000MPa vs. 240), there is absolutely no reason a carbon foil should weigh more than aluminum. Eliminating material reduces weight, cost, and environmental footprint. On a per-pound basis, carbon fiber emits more than 10x the CO2 emissions of metals before it’s converted to a useful product, and it’s not easily recycled at end of life. When you’re building an airplane with it, that cost can easily be justified over the 30 year lifespan using significantly less fuel. When building a small pleasure craft on the other hand, it’s hard to rationalize the energy intensity and manufacturing waste unless there are more obvious benefits. A lot of people have told me the weight of the foil doesn’t matter, to which I will continue to disagree. If you don’t care about weight, you should at least care about cost and environmental impact of your toys. That being said, once you ride a lightweight foil, you will never go back.
Safety was also an important design factor for me. I sliced my foot open on my first day learning to foil in Baja, and was frustrated to spend the rest of my trip in pain. There’s no reason for the leading and trailing edge of kite foils to be so sharp and hard; our sport is already dangerous enough. Before teaching my wife to foil, I knew we needed a better and safer tool. A lighter weight foil is inherently safer, having less kinetic energy and momentum after a crash. That being said, I knew I had to get creative with my edges to really improve safety.
I think I can speak for all riders when I express frustration at the lack of industry standard for board connections and wing attachments. We finally appear to be converging on a combination of plates and conical board boxes, but we have a long way to go before we have the equivalent to a DIN ski bindings or bike wheel skewers. My goal was to simply make the best mast in the world, and allow it work with any board or any set of wings. You should be able to ride your foil on any setup, not be locked into a specific brand or design. I love traveling with my F-One Mitu Convertible foil/surf board, but like using my floaty Liquid Force Happy Pill at home. I know many people out there have surf, SUP, race, or stubby boards and don’t want, or simply can’t afford, more than one foil.
While not a primary objective of mine, I knew my price could be favorable in the end with the right design and manufacturing process. Building composite components is very rate sensitive. The hand-layed prepreg design does not scale well, which is why they are so expensive. Automated fiber placement or tape layup can reduce labor costs, but you’re looking at hundreds of thousands of dollars in non-recurring costs. Carbon fiber prepreg is about $20/lb, while aluminum is around $3. Sounds like a big difference, but we are talking about a few pounds of material in a typical mast. The big cost driver for composite sporting equipment is manufacturing and labor hours, all of which occur in Asia these days, not the material itself. A properly designed composite structure can be less expensive than metallics.
My prototype mast, ignoring my hours, cost as much to make as buying a new carbon foil off the shelf (including the molds!). This is thanks to an efficient process and tooling, which can scale easily if demand is there. In a way, the industry is shooting themselves in the foot by changing their designs every year. Doing so eliminates the ability to invest in better tooling and technology, but instead results in money spent on marketing and graphics design. I want to change that. I want to shift the industry from sales-driven to technology-driven. As consumers, we also play a role. Instead of falling for the marketing hype and upgrading our quiver every year, hold off until there is a real, obvious, technological improvement. Model year numbers are not improvements, and I will never attach them to my products.
Project Cedrus is the end of black aluminum. The mast is so light, it floats on water. It attaches to any board, and is compatible with a number of different wings. It’s hand made in Oregon along the Columbia River, designed by riders and for riders. Read on for more details regarding the architecture, design process, and how to be a part of the release.