A compact clutch assist device has an assist mechanism operating between a clutch operating lever and a transmission clutch. The clutch assist device is interposed between a first clutch wire connected to the clutch operating lever and a second clutch wire connected to the transmission clutch. The clutch assist device selectively urges the clutch wires in such a direction as to assist disengaging the transmission clutch. The clutch assist mechanism has a case and a rotatable member that is housed in the case. The rotatable member receives an urging force of an auxiliary force member. In one embodiment, the auxiliary force member is coupled to the rotatable member through a cam mechanism.