A composite one-piece hollow-core wheel is entering the wheelchair market. ``We mold a hook bead rim as a unified part of the wheel and eliminate the aluminum hub,'' said Kirk Jones, president of Innova-tions in Composites Inc. in Ocean-side, Calif. ``We reduce labor, handling and the number of parts.''
The company's reputation rests on its success with Spin bicycle wheels. Now, Innovations in Composites is improving the technology for use on wheelchairs. The low-maintenance wheels represent a technological and durability leap over the century-old wire-spoke wheels they are intended to replace.
A premium model of the wheel, the Pro X-Core 5, contains reinforced Celstran long-carbon-filled fiber from Polymer Composites Inc., carries a granite-marble finish and has greater stiffness than another version. That model, known as X-Core 5, uses high-impact Capron glass-filled nylon from AlliedSignal Plastics, meets the price of wire-spoke wheels and has a smooth black finish.
``One company thought it was painted,'' Jones said.
Epic Technical Group custom molds the wheels on a fully automated lost-core molding cell at a plant in Dover, Ohio. Epic, a unit of auto parts maker Echlin Inc. of Branford, Conn., uses a robotic 1,000-ton Nissei press in the process.
Making the one-piece wheel entails overmolding an internal mandrel of a low-melting-point metal alloy with thermoplastic. Then the mandrel, or core, is melted out.
The design from Innovations in Composites cuts out need for machining, two cleaning steps, sand blasting, trimming and ``an expensive adhesive,'' Jones said. ``Output can be much higher when the process is automated and secondary operations are eliminated.''
Jones is marketing the innovation to wheelchair manufacturers including Invacare Corp. of Elyria, Ohio; Sunrise Medical Inc. of Carlsbad, Calif.; and Everest & Jennings International Ltd. of Earth City, Mo., but he expects smaller firms to sell the wheel initially.
``The orders have started rolling in,'' he said.
Innovations distributes its popular molded bicycle wheel of long-carbon-fiber-reinforced Celstran nylon through GT Bicycles of Santa Ana, Calif.
``We can't keep up [with demand] because of post-machining,'' Jones said.
In the next marketing step, GT plans to sell the ATB, BMX and 650C wheels as original equipment. Previously, GT offered the hollow-core wheel only through aftermarket outlets.