Patent ID: 8136628

Claim:
An exhaust system for a motorcycle, comprising: an exhaust pipe connected to an engine; and a silencer connected to the exhaust pipe, the silencer comprising: a hermetically sealed first tubular body; and a second tubular body coaxially disposed within the first tubular body, the second tubular body having a front end portion connected to the exhaust pipe and a rear end portion opened toward the atmosphere, wherein the second tubular body includes an outlet tube, the outlet tube comprising a reduced diameter portion with a diameter which becomes smaller in the downstream direction, a throttle portion connected to the reduced diameter portion and having a constant diameter, and an enlarged diameter portion connected to the throttle portion, the enlarged diameter portion having a diameter which becomes larger in the downstream direction wherein the outlet tube further comprises a large-diameter straight tube connected to a downstream end of the enlarged diameter portion, the diameter of the large-diameter straight tube being equal to the diameter of the downstream end opening of the enlarged diameter portion.