A shaft characterized by its length to diameter ratio being less than about 1.75 having a drive connection at one end where the wall thickness of the shaft is selected to be thick enough to avoid ellipticalization strain error in torsional measurement of less than 5%. One specific application is for a crankset spindle that can be used to measure a cyclist right, left, and total leg torque.

A cycling pedal assembly consisting of a body configured to spin, slide, and pivot on a horizontal rotational axis formed by an axle, roller bearing, and spherical rolling joint.

A pedelec bottom bracket drive unit includes a rigid drive housing and a tolerance compensation sheet-metal spring which is arranged to stand substantially in a vertical plane. The tolerance compensation sheet-metal spring includes at least one fixing point at a housing side and at least one mounting point for fastening the tolerance-compensating sheet-metal spring to a pedelec-frame-side drive mount. The at least one fixing point has a fixing point traverse axis. The tolerance compensation sheet-metal spring is fixed to the rigid drive housing at the at least one fixing point at the housing side. The at least one mounting point has a mounting point traverse axis. The at least one mounting point is arranged offset with respect to a next adjacent fixing point of the at least one fixing point as viewed from the fixing point traverse axis and from the mounting point traverse axis.

A drive train for muscle-driven single-track or multi-track vehicles with a crank-driven bottom bracket gearbox which is connected on the output side to a chain or belt drive from which a chain or belt leads directly or shiftably to a pinion to a rear wheel hub. belt leads directly or switchably in each case to a pinion to a rear wheel hub, wherein in addition to the bottom bracket gearbox, which is designed as a primary gearbox with n speeds or with variable transmission ratio, a rear-mounted gearbox is also arranged in the drive train as a switchable rear wheel hub gearbox with m=two or m=three speeds, wherein n and m are natural numbers. In addition to the bottom bracket gearbox, which is designed as a primary gearbox with n speeds, the drive train also includes a rear-mounted gearbox as a shiftable rear wheel hub gearbox with m=two or m=three speeds.

A bicycle includes a frame, and a transmission device including a motor, a transmission unit, a crank unit, a sprocket and a unidirectional bearing. The transmission unit includes a first gear driven by the motor, a one-way clutch mounted in a compartment of the frame and connected between the first gear and the motor for limiting rotation to be transmitted from the motor to the first gear, and a second gear meshing with the first gear. The crank unit includes a crank shaft extending into the second gear, and first and second cranks connected respectively to two ends of the crank shaft. The sprocket is formed with an engaging hole non-rotatably engages the second gear and a receiving groove receives the unidirectional bearing for driving rotation of the sprocket in a single direction.

A pedelec bottom bracket drive unit includes a rigid drive housing and a tolerance compensation sheet-metal spring which is arranged to stand substantially in a vertical plane. The tolerance compensation sheet-metal spring includes at least one fixing point at a housing side and at least one mounting point for fastening the tolerance-compensating sheet-metal spring to a pedelec-frame-side drive mount. The at least one fixing point has a fixing point traverse axis. The tolerance compensation sheet-metal spring is fixed to the rigid drive housing at the at least one fixing point at the housing side. The at least one mounting point has a mounting point traverse axis. The at least one mounting point is arranged offset with respect to a next adjacent fixing point of the at least one fixing point as viewed from the fixing point traverse axis and from the mounting point traverse axis.

A composite bicycle crank with an integral spindle attachment structure provides a unique method for attaching a bicycle crank arm to a bicycle crank spindle, and also for attaching a bicycle crank arm to a crank arm insert. A light-weight crank arm is able to be manufactured separately from the crank spindle or insert, and then securely attached after both pieces have been made. This allows for the pieces of the crank assembly to be manufactured from one or more different materials, and securely connected after manufacturing, to create a lower weight assembly than would be possible otherwise.

A cycle crank assembly includes a crank spindle and a drivetrain connector configured to translate rotation of the crank spindle into rotation of a wheel. A crank arm includes a pedal interface configured to receive a pedal spindle of a cycle pedal. A slip connection is configured to allow the crank arm to rotate about the crank spindle. A resiliently deformable member is connected to the crank spindle and the crank arm proximate to the pedal interface. The resiliently deformable member translates rotation of the crank arm into rotation of the crank spindle. The resiliently deformable member deforms under load to store pedal energy provided by a rider to the cycle pedal and returns at least a portion of the pedal energy when not under load in a direction of the rotation.

A bicycle crank arm apparatus comprises a crank arm having a crank axle mounting portion and a pedal mounting portion. A circuit-mounting structure is disposed between the crank axle mounting portion and the pedal mounting portion, wherein the circuit-mounting structure is configured to detachably mount a measurement board. When a measurement board is mounted to the circuit-mounting structure, the resulting combination forms a bicycle input force processing apparatus.

An auxiliary power device adapted for use with a bicycle includes a drive unit, first and second one-way transmissions that are adapted to be mounted in a bike frame of the bicycle, a crankshaft and a transmission sprocket. The first one-way transmission is connected between the drive unit and the transmission sprocket. The second one-way transmission is mounted between the crankshaft and the transmission sprocket. When rotation of the transmission sprocket is driven by the drive unit via the first one-way transmission, the second one-way transmission is idling. When rotation of the transmission sprocket is driven by the crankshaft via the second one-way transmission, the first one-way transmission is idling.