A power measurement assembly mounted within an axle. In a specific example, the axle is a spindle that is interconnects the cranks of a bicycle, exercise, bicycle, or other fitness equipment. The power measurement assembly may include strain gauges connected with an appropriate circuit (e.g., Wheatstone bridge) that provides an output of the force on the axle by a rider pedaling the crank. In the case of an axle, the strain gauges measure the torsion due to the applied torque on the crank. The value is converted to a power value by a processor and that value is then wirelessly transmitted for display. The processor and/or the transmitter may be mounted within the axle. A separate power measurement assembly may be mounted on one of the cranks, which may include its own processor and transmitter or may take advantage of the processor and transmitter within the axle.

A bicycle (10) includes a frame (25) having a bottom bracket (40), a crankset (35) attached to the bottom bracket (40), a pedal (50) coupled to the crankset (35) and operable to propel the bicycle (10) in response to a force acting on the pedal (50). The bicycle further includes a first bicycle component acted upon by the pedal (50) in response to the force, a second bicycle component coupled and responsive to the first bicycle component, and a power vector sensor (85) coupled to and positioned between the first bicycle component and the second bicycle component, and the power vector sensor (85) includes a sensor element (100) to sense a force transferred from the first bicycle component to the second bicycle component and indicative of the force acting on the pedal (50).

A torque detector detects a torsional torque between a first shaft and a second shaft based on a torsional displacement of an elastic member coaxially connecting the first shaft and the second shaft. The torque detector includes a magnetic flux generation unit and a magnetic sensor. The magnetic flux generation unit rotates with rotation of the first shaft and includes a first pole and a second pole into and out of which lines of magnetic force enter and exit. The magnetic sensor rotates with rotation of the second shaft and includes a detection surface for detecting a magnetic flux or a magnetic flux density. The first pole and the second pole are arranged to face each other across the magnetic sensor.

A power meter for a bicycle includes a body having a torque input section and a torque output section, the body configured to transmit power between the torque input section and the torque output section. The power meter also includes an electronic device having one or more antennae configured to communicate a signal wirelessly.

Power transmitted from a cyclist to a bicycle through crank arms is indirectly measured by performing calculations on direct physical measurements. The direct physical measurements are taken from sensors that can be non-rotationally coupled to the frame of the bicycle. The sensors can be integrated into the frame or installed as a module within a standard, unmodified bicycle bottom bracket. Measured power can be viewed by the cyclist using a wirelessly connected user interface device.

A method and a device for measuring a tangential reaction force of a resistance device on a flywheel, and the reaction force multiply the radius of the flywheel to obtain a torque, such that the torque multiply a gear ratio is the torque to overcome the resistance of flywheel on the drivetrain. The torque to overcome the resistance of flywheel on the drivetrain adding a torque to overcome the inertia of the flywheel and mechanical friction under the state of no resistance is the total torque presented on the drivetrain. Such that using the total torque to calculate power and energy consumption.

The method involves a step of measurement of a bearing force (Fp.sub.n) on a pedal (1) of the pedal set (4), different from the useful effort, exerted by the individual during a pedalling cycle, a step of determination of a maximum (max(Fp.sub.n)) of the bearing force measured during the pedalling cycle (CP.sub.j), and a step of estimation of a mean useful effort exerted by the individual during said pedalling cycle from the maximum of the bearing force determined and with the aid of a predetermined correlation function between a maximum bearing force during a pedalling cycle and a mean useful effort in said cycle.

A method estimates a torque of a heat engine in a vehicle hybrid transmission including at least a heat engine and an electric machine together or separately supplying a heat engine torque and heat engine torque intended for wheels of the vehicle. The method uses a measurement of a speed of the heat engine, a value of the heat engine torque reference, and a value of the electric machine torque. The method also sums an estimate of a total torque supplied by the transmission to the wheels and of an estimate of an equivalent resistive torque of the transmission to determine the estimated heat engine torque.

Power transmitted from a cyclist to a bicycle through crank arms is indirectly measured by performing calculations on direct physical measurements. The direct physical measurements are taken from sensors that can be non-rotationally coupled to the frame of the bicycle. The sensors can be integrated into the frame or installed as a module within a standard, unmodified bicycle bottom bracket. Measured power can be viewed by the cyclist using a wirelessly connected user interface device.

A power measurement assembly mounted within an axle. In a specific example, the axle is a spindle that is interconnects the cranks of a bicycle, exercise, bicycle, or other fitness equipment. The power measurement assembly may include strain gauges connected with an appropriate circuit (e.g., Wheatstone bridge) that provides an output of the force on the axle by a rider pedaling the crank. In the case of an axle, the strain gauges measure the torsion due to the applied torque on the crank. The value is converted to a power value by a processor and that value is then wirelessly transmitted for display. The processor and/or the transmitter may be mounted within the axle. A separate power measurement assembly may be mounted on one of the cranks, which may include its own processor and transmitter or may take advantage of the processor and transmitter within the axle.