A pressure detection unit includes a front-wheel transmitter and a rear-wheel transmitter operatively connected to wheel rims of a front wheel and a rear wheel, respectively. Inflation pressure signals transmitted from the front-wheel transmitter and the rear-wheel transmitter are received by a receiver. The receiver is arranged to be offset outward of a straight line connecting the front-wheel transmitter and the rear-wheel transmitter in the vehicle-body width direction. More specifically, the receiver is arranged in a space surrounded by a front cowl and a side panel, the space being between a coolant reserve tank and a radiator. The single receiver receives the signals transmitted from the front-wheel transmitter and the rear-wheel transmitter.