DETROIT-Serpentine belts are almost completely replacing V-belts on new vehicles in North America and Japan. As that happens, at least three U.S. firms are fighting for a piece of the growing, lucrative aftermarket. Goodyear, Dayco Products Inc. (a subsidiary of Mark IV Industries Inc.) and Gates Rubber Co. market replacement serpentine belts.
Serpentine belts are drive belts that follow complex paths over several pulleys to drive various engine accessories. The belts were introduced in the 1950s for industrial applications, said Wayne Manthei, Goodyear manager of transportation replacement products. The belts didn't show up on U.S. cars until 1977, he said.
Today, more than 95 percent of new vehicles from Detroit use serpentine belts instead of the traditional fan belts, Mr. Manthei said. More than 50 percent of the 192 million vehicles in the United States use serpentines.
A great market also is available in Japan, where most of that nation's 64 million vehicles use serpentine belts for power transmission applications, he said. During the first four months of 1996, both Goodyear and Gates signed contracts with Japanese distributors.
The attraction of serpentine belts is obvious: ``You have one belt replacing anywhere from three to seven (V-belts),'' said Dennis Virag of the Automotive Consulting Group. And serpentine belts are more durable than V-belts, according to a report by the Freedonia Group Inc., a research firm in Cleveland.
Freedonia does not know the exact size of the serpentine market. But it said U.S. shipments of nonflat belts-with the largest nonflat belt segment being automotive serpentine and V-belts for original-equipment and replacement applications-is expected to reach $1.38 billion in 1998.
The change was brought about by the move toward smaller, lighter vehicles, and the serpentine belts let automakers reduce the size and weight of engines.
Aftermarket sales of the serpentine belts in the U.S. started during the last five to six years and has become one of the fastest-growing market segments, said Ed Rammel, vice president of marketing for Mark IV Automotive.
Automakers are pushing the three suppliers to ``eliminate all noises that might be contributed by a belt,'' a Gates spokesman said.
Dayco introduced its Poly Cog belt in 1990, Gates released the latest version of its Gates Micro-V two years ago, and last year Goodyear began promoting its new Gatorback Poly-V. All three firms tout their belts as quiet products that can even overcome the noise caused by misaligned pulleys.
Gatorback reduces misalignment noise with a rubberized fabric backing, Mr. Manthei said. It boasts a fiber-reinforced, helical-cogged rib design that gives the belt an alligator-like texture. The design prevents heat buildup and weakening in the belt, giving it 30 percent more life than rival serpentine belts, he said.
Gatorback sales are growing at a double-digit rate, Mr. Manthei said, and customers are beginning to ask for the Gatorback by name.
Dayco said its Poly Cog belt features staggered cog spacing that ``virtually eliminates harmonic noise, while reducing susceptibility to `chunk out' and groove jumping.''