Competition Motorcycle Noise Measurements-A Correlation Study

A noise measuring program during the running of flat-track races for 750-cc, four-stroke, twin-cylinder competition motorcycles showed that the noise measured under actual track conditions correlated fairly well with the American Motorcycle Association's (AMA) 4,000-rpm static test method of predicting noise. Equations are presented that, if substantiated, can be used to accurately forecast from the AMA static test results the noise levels that will be generated during such events. The motorcycles, equipped with mufflers, projected significantly fewer decibels into the local community than local officials had deemed objectionable. However, the racing cyclists and their pit crews experienced noise levels loud enough to cause permanent irreversible hearing damage.