TIRE DEVICE

A tire device has a tire side device and a vehicle body side system, and determines a road surface condition and detects a tire wear state. The tire side device includes a vibration detection unit that outputs a detection signal according to a magnitude of a tire vibration, a control unit extracts a feature amount during one rotation of the tire, and a first data communication unit that transmits a road surface data including a feature amount. The vehicle body side system includes a second data communication unit that receives road surface data, a road surface determination part that determines a road surface condition based on the road surface data, an integral calculation part that calculates an integral value of the feature amount in a specific frequency band included in the road surface data, and a wear determination part that detects the tire wear state from the integral value.