Auto emissions are the No. 1 cause of air pollution. Motor vehicles are responsible for 55 percent of cancer contaminants, greater than any other source, according to the League of American Bicyclists. Somerville sued the bike companies after he hit a stone wall while riding down the paved auto road from the mountain summit on Aug. 5, 1990. He believes the front tire rolled off the rim. It was a tubular tire, or sew-up, as opposed to the more common clincher.
Clinchers use separate inner tubes and are seated on the rim with air pressure.
Somerville's lawyer argued that the manufacturers and retailers did not provide adequate instructions for the sophisticated sew-up tire. Defendants contributing to the settlement included frame maker Toshuku, rim maker Mavic, tire manufacturer Hutchinson, and retailers Performance Inc. and Bicycle Alley of Worcester. Somerville, a Texas native, had moved to Worcester for a residency in anesthesiology at the University of Massachusetts medical center. He completed his medical training after the crash and has a medical practice in Laredo, Texas. The first federal standard for bike helmets went into effect last month, covering helmets manufactured after March 10.