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October 2015 — 11 what you'd see in a vehicle over 300,000 kilometers." However, at 130% of standard, the requirement Carbon Revolution set for itself, was beyond the burst limit for the rear tires. "We had to run it to 125%," says Dingle. "Carbon fber composites have an almost infnite fatigue life," he says, "but there have been questions about how it would perform on impact as the material has a reputation for being brittle, especially when impacted the 'wrong' way." They needn't have worried. In destructive tests replicating a serious accident, designed to highlight whether or not the material has a safe failure mode, an aluminum wheel will split open circumferentially. "Ours are designed to fail on the outer bead so you can see it, and it gives a slow air loss," says Dingle. "Certifcation bodies and OEMs favor failure modes that are readily apparent to the average consumer." When Ford called, it wanted to be certain the composite wheel would meet all of its requirements. That meant subjecting the wheels to a lifetime of sun exposure to see how UV rays would afect the carbon fber resins, running them against curbs at speed, and exposing them to the extreme high temperatures produced by the GT 350R's hybrid aluminum hat/ cast iron disc Brembo brakes. According to Brett Gass, Carbon Revolution's Executive Director, "The process is proprietary to Carbon Revolution, and plasma arc sprays a multi-layer coating on the wheel's inner barrel and spokes." This ceramic material protects these areas from the 1,652º F (900º C) heat that can be generated by the GT 350R's brakes under hard use. The wheels also receive a special coating designed to shrug of road salt and UV degradation, though the idea of a GT 350R playing in the snow is a bit … ridiculous. "The goal from the outset has been as much on manufacturability as on the product itself," Dingle declares. That means the Carbon Revolution design doesn't require the use of an autoclave or the $100/ kilogram pre-preg process. Instead, it uses dry fbers and is closer in concept to a classic resin transfer molding (RTM) procedure, though it has been designed to be something that is "light industrial" in terms of energy, infrastructure and automation. The work with Ford has pulled Carbon Revolution along to its next step, a production setup that can build 250,000 wheels per year. "The process can be expanded relatively easily," says Gass, "by adding lines in parallel. It's a very low energy process with robots for the placement and cutting of the tailored fbers, and will allow us to achieve aerospace quality levels." Yes, aerospace. With weight a major determinant of fuel use and cargo capacity, pulling weight out of an airplane is proftable. "Aerospace is quoting $3,000 per kilogram per year in fuel cost," says Denmead. Extrapolate that against the 14 to 16 wheels per aircraft, multiply that across a feet of planes and then add in the retroft feet, and you have a market ripe and ready to pay for this technology. Heavy trucks are another. Painted truck wheels that don't corrode, are built at low cost, and have a long life while conferring fuel savings are very attractive. As these projects move forward, another lurks in the background, and it may be the most signif- cant yet. According to Denmead, there is a plan for a value- engineered product in the "low hundreds of dollars per wheel that would be painted and with metal bits that are value engineered instead of hard anodized." A 17-in. wheel built to these specs would weigh about 4.5 kg (10 lb.) with a weighted average material cost of less than $10/kg. Even with the labor, paint and ftting costs added on top, carbon fber wheels would still be very competitive with alloy designs. "Now you can see why [alloy wheel maker] Ronal is an investor," says Gass. Helping to drive the move toward a signifcantly lighter wheel in volume production is the legislative landscape. Not only do automakers have to dramatically reduce the weight of their vehicles in the next decade to meet fuel economy regulations, legislation is pending that will require a full lifecycle analysis of the car and its components from cradle to grave. "We do very well in that analysis," says Gass. And, as automakers increase their use of carbon fber and drive the industry to create better fbers and resins at lower cost, Carbon Revolution benefts. "Our production process is independent of a particular fber or resin," says Gass. "As they improve, we improve." Further, each $100-million invested to erect a major carbon fber plant will create the capacity necessary to move to alloy wheel production levels (2.5 million units/year, which will require about 20,000 tons of carbon fber) cost efectively. As to how long this next step will take, no one is saying. However, with CAFE standards tightening considerably in the 2020 to 2025 timeframe, the time for this revolution is near.