A chainring assembly includes a chainring carrier adapted to be coupled to a crank arm. The chainring carrier is rotatable about a rotation axis, and includes an outer periphery having carrier threads. A chainring structure includes an inner periphery having chainring threads and an outer periphery comprising a plurality of teeth. The inner periphery of the chainring structure is threadably engaged with the outer periphery of the chainring carrier. In one embodiment, a power meter device includes a body having a torque input section and a torque output section, with the torque output section including an outer periphery having threads adapted to be coupled to a chainring structure.

A chainring assembly includes a chainring carrier adapted to be coupled to a crank arm. The chainring carrier is rotatable about a rotation axis, and includes an outer periphery having carrier threads. A chainring structure includes an inner periphery having chainring threads and an outer periphery comprising a plurality of teeth. The inner periphery of the chainring structure is threadably engaged with the outer periphery of the chainring carrier. In one embodiment, a power meter device includes a body having a torque input section and a torque output section, with the torque output section including an outer periphery having threads adapted to be coupled to a chainring structure.

A crank measurement system includes four bend-sensing strain gauges located on one surface of a crank and oriented parallel to a neutral axis of the crank to sense bend strain induced in the crank. Two of the bend-sensing strain gauges are located above the neutral axis, and the other two bend-sensing strain gauges are located below the neutral axis. The system also includes two shear-sensing strain gauges located on the one surface and oriented to sense shear strain induced in the crank. The shear-sensing strain gauges are located on opposite sides of the neutral axis. The system may also include up to four axial-sensing strain gauges located on the one surface and oriented to sense axial strain induced in the crank. An electronics module receives strain data from the strain gauges, and determines from the strain data one or more of force, torque, and power applied to the crank.

A crank measurement system includes four bend-sensing strain gauges located on one surface of a crank and oriented parallel to a neutral axis of the crank to sense bend strain induced in the crank. Two of the bend-sensing strain gauges are located above the neutral axis, and the other two bend-sensing strain gauges are located below the neutral axis. The system also includes two shear-sensing strain gauges located on the one surface and oriented to sense shear strain induced in the crank. The shear-sensing strain gauges are located on opposite sides of the neutral axis. The system may also include up to four axial-sensing strain gauges located on the one surface and oriented to sense axial strain induced in the crank. An electronics module receives strain data from the strain gauges, and determines from the strain data one or more of force, torque, and power applied to the crank.

A bicycle trainer compensation algorithm based on multi-groove belts sliding relative to one another includes: determining a load interval and a rotating speed range, recording an external driving torque, a rotating speed, a measured torque and a no-load mechanical loss of the bicycle trainer under conditions of different loads and different rotating speeds, and obtaining a relationship between a mechanical loss of a whole machine and the different rotating speeds, the different loads, and the no-load mechanical loss, fitting a plurality of sets of relationships to obtain an algorithm relation, verifying universality of the algorithm relation, and further fitting to obtain a compensation algorithm relation, and verifying whether a compensation accuracy of the compensation algorithm relation is satisfied within an error requirement.

A device for measuring horological shakes, including a structure carrying an articulated mechanism with a compliant mechanism having a linear force/stroke characteristic connecting a first fixed element to a second element capable of moving linearly under the effect of an actuator manoeuvring same in a contactless manner in both directions, and a position sensor determining the position of the second element in a direction, and a load sensor determining the variation in the axial pushing or pulling load of the second element carrying a gripper clamping a mobile component, and/or the variation in the gradient of this load, generating a signal for triggering the position measurement during each sudden change in gradient of the load in each direction of running, to determine the shake of the mobile component, by comparing the positions measured during the sudden changes in gradient during the outward and return strokes.

An ink blend consisting of a polymer, a weakly cross-linking agent and a nanomaterial deposited to form a thin polymer-nanomaterial composite film with unique mechanical and electrical properties suitable for high performance strain sensing applications.

An axle assembly for a bicycle includes an axle having an inner wall extending along a length of the axle between a first end and a second end of the axle. The inner wall at least partially defines a first volume and a second volume within the axle. The first volume has a first diameter, and the second volume has a second diameter that is greater than the first diameter. The first volume is closer than the second volume to the first end of the axle. The axle assembly also includes a sensor attached to the inner wall of the axle within the second volume of the axle.

This disclosure presents a dimensionless relationship between a fluid flow rate, a viscosity, and a brake horsepower (BHP) in a pump operation and a method that uses the dimensionless relationship to predict a BHP for viscous performance of a pump from water performance specifications. Using the dimensionless relationship, i.e., K-R number, the methods determine a BHP correlation that allows the prediction of the BHP specification to satisfy a pump performance metric at any given speed, flow rate, and viscosity. This prediction can be calculated from water performance specifications without physically testing the pump in the viscous implementation environment.

This disclosure presents a dimensionless relationship between a fluid flow rate, a viscosity, and a brake horsepower (BHP) in a pump operation and a method that uses the dimensionless relationship to predict a BHP for viscous performance of a pump from water performance specifications. Using the dimensionless relationship, i.e., K-R number, the methods determine a BHP correlation that allows the prediction of the BHP specification to satisfy a pump performance metric at any given speed, flow rate, and viscosity. This prediction can be calculated from water performance specifications without physically testing the pump in the viscous implementation environment.