A clutch drive unit 220 includes a crank arm 221 configured to rotate by rotary driving of a clutch actuator 231. The crank arm 221 includes an output pin 222 configured to press a master cylinder 232, and a receiving pin 223 configured to receive pressing force P from an extendable body 228. The extendable body 228 includes a lock spring 228a with such strength that the pressing force P is generated. The pressing force P allows pressing moment PM greater than reactive force moment RM based on reactive force R acting on the crank arm 221 from a clutch 210 to act on the crank arm 221. The extendable body 228 is, by the stretching force of the lock spring 228a, provided in a stretched state between the receiving pin 223 and a holder receiving pin 229.