A clutch mechanism includes a friction clutch with a clutch spring, a clutch lever connected to the friction clutch via clutch wires and being manually operable against the urging force of the clutch spring, and a clutch assisting device. The clutch assist device has an assist mechanism having an auxiliary force member (e.g., a spring) that urges the clutch wires in such a direction as to disengage the friction clutch while the clutch lever is moved from a disengage start position, where the clutch lever receives the reactive force of the clutch spring, to a disengaged position, where the disengagement of the friction clutch is completed. The assist mechanism maintains the urging force of the auxiliary spring applied to the clutch wires within a fixed range while the clutch lever is shifted from the midpoint between the disengage start position and the disengaged position to the disengage position. The clutch assist device reduces the manual force required to operate the clutch while preserving the operational feel of the clutch lever when moving the lever from a released position to a half clutched position, to a full clutch position.