A sensor-equipped hub unit comprises a hub unit 1 having a wheel-side
raceway member 4, a body-side raceway member 5, and two rows of rolling
bodies 6, and a sensor device 2 provided on the hub unit 1. The sensor
device 2 has a magnetostrictive sensor 31 for detecting a reverse
magnetostrictive effect of the raceway member 4 produced by a force
exerted thereon by the rolling bodies 6. The sensor device 2 detects
rotation from the number of repetitions of a variation in strain and also
detects the force acting on the wheel-side raceway member 4 from the
amplitude of strain.