Torque-measuring hub, system for measuring power and cycle wheel provided with such a hub or such a measurement system and method using such a hub

The hub (2) has a central shaft (10) defining a rotation axis (X) of a cycle wheel, and a hub body (20) mounted to rotate freely about the shaft. The hub body comprises a central portion bordered on opposite axial sides by anchoring zones of a fixing element formed by grooves (23). The fixing element fixes connecting elements i.e. driving spokes, connecting the hub body to a rim of the cycle wheel. A power measurement system (60) measures driving torque of the wheel and includes strain gauges (6.1) fixed on the hub body. Independent claims are also included for the following: (1) a system for measuring a driving power of a cycle wheel (2) a method for measuring a driving torque of a cycle wheel.