An exhaust chamber (34) for a motorcycle is disposed at a location upstream of a muffler (36) of an exhaust passage (38) leading from a combustion engine (E). The exhaust chamber (34) includes a chamber body (40) having expansion compartments (41, 42, 43) defined therein, a chamber outlet pipe (46) having an outlet passage defined therein for discharging the exhaust gases (G) from the chamber body (40), and an exhaust control valve (72) disposed in the chamber outlet pipe (46) for adjusting the sectional area of the outlet passage inside the chamber outlet pipe (46).