An Empirical Approach to Motorcycle Silencing

This paper describes a simple inexpensive system of motorcycle silencing which has given successful results on prototype and production, touring and competition, 2-stroke and 4-stroke machines. Noise sources are identified and compared. The noise from principal sources is silenced by several techniques, but mainly using the Annular Cavity type of unit developed earlier. The procedure for tuning is discussed, using the case history of a 380 cc 2-stroke enduro motorcycle. Reduction of intake and exhaust noise is typically 12 - 25 dBA, with a useful increase in power.