A distance A2 from the center P1 of a pivot 16 to an abutting portion between a slave cylinder side operation arm 14c ad a piston end of an interlocking slave cylinder 9 is smaller than a distance A1 from the center P1 of the pivot 16 to an abutting portion between a master cylinder side operation arm 14b and a piston end of a front-wheel hydraulic pressure master cylinder 3. At the time of a full stroke of a second piston 25 of the interlocking slave cylinder 9, a first piston of the front-wheel hydraulic pressure master cylinder 3 does not reach a full stroke.