An electric assist system usable for an electric assist bicycle includes an electric motor that generates assist power assisting human power of a rider of the electric assist bicycle, a rotation sensor that outputs a signal in accordance with a rotation of a rotatable component that rotates to operate the electric assist bicycle, an acceleration sensor that outputs a signal in accordance with an acceleration of the electric assist bicycle in a traveling direction thereof, and a controller that calculates a speed of the electric assist bicycle based on an output signal of the rotation sensor and an output signal of the acceleration sensor.

An electric assist system usable for an electric assist bicycle includes an electric motor that generates assist power assisting human power of a rider of the electric assist bicycle, a rotation sensor that outputs a signal in accordance with a rotation of a rotatable component that rotates to operate the electric assist bicycle, an acceleration sensor that outputs a signal in accordance with an acceleration of the electric assist bicycle in a traveling direction thereof, and a controller that calculates a speed of the electric assist bicycle based on an output signal of the rotation sensor and an output signal of the acceleration sensor.

A chain and an inner link plate for a bicycle chain having chain rollers is provided. A protrusion of the inner link plate in relation to the respectively assigned chain roller in a front lower longitudinal end region of an inner link plate outer periphery is reduced, in comparison to the protrusion in a front upper longitudinal end region and/or in a rear lower longitudinal end region of the inner link plate outer periphery.

A two-seater off-road vehicle includes a travel vehicle body that is supported on the ground by a front wheel unit and a rear wheel unit, and a boarding part disposed above a vehicle body frame included in the travel vehicle body. The boarding part includes: a driver seat; a steering operation tool in front of the driver seat; and a passenger seat of a saddle seat type behind the driver seat.

A two-seater off-road vehicle includes a travel vehicle body that is supported on the ground by a front wheel unit and a rear wheel unit, and a boarding part disposed above a vehicle body frame included in the travel vehicle body. The boarding part includes: a driver seat; a steering operation tool in front of the driver seat; and a passenger seat of a saddle seat type behind the driver seat.

A gearbox may include a drive spindle and several interconnected gear clusters arranged in a housing. A first of the gear clusters is coaxially fastened to the spindle, and has an outboard gear and an inboard gear. The first gear cluster drives a belt to operate one or more of the other gear clusters, and the inboard gear is physically divided into a plurality of segments. A shifting system for the gearbox includes an actuator configured to urge the segments of the inboard gear of the first gear cluster into and out of the plane of the belt, such that a gear ratio of the gearbox is changeable without displacing the belt out of the plane.

A transmission structure of electric clutchless motorcycle includes an electric motor, a variable speed gear set, a variable speed gear box and a gear position sensing unit. The arrangement of the gear position sensing unit is so configured that the transmission structure of electric clutchless motorcycle mechanism not only maintains the inertial energy recharge of the electric motor to increase the endurance of the vehicle, but also allows the driver to accurately control the speed control knob when switching gears, and furthermore can increase the automatic gear shift function of the electric gear shift design.

A transmission structure of electric clutchless motorcycle includes an electric motor, a variable speed gear set, a variable speed gear box and a gear position sensing unit. The arrangement of the gear position sensing unit is so configured that the transmission structure of electric clutchless motorcycle mechanism not only maintains the inertial energy recharge of the electric motor to increase the endurance of the vehicle, but also allows the driver to accurately control the speed control knob when switching gears, and furthermore can increase the automatic gear shift function of the electric gear shift design.

The present invention is a chain structure of bicycles, which comprises a plurality of rollers, a plurality of chain sheets and a plurality of chain rollers. Wherein the rollers define a mounting space. Each chain sheet comprises a chain body, a first pivot joint part extending from one end of chain body and to be arranged in the mounting space, a second pivot joint part horizontally extending from the other end of chain body, the second pivot joint part is installed on the roller with the first pivot joint part, wherein the first pivot joint part is in a horizontal position different from chain body, the first pivot joint part defines a rotation space for placing the second pivot joint part of another chain sheet, so that the first pivot joint part and second pivot joint part can rotate a preset angle in the rotation space. When the chain sheets are combined with rollers respectively, the chain bodies remain on the same plane, the chain roller penetrates the second pivot joint part and the first pivot joint part respectively for connecting the roller to the chain sheets on both sides of roller. Thereby, the chain is thinned and the weight is reduced, the tensile strength is increased by thickening the chain sheet.

The present invention is a chain structure of bicycles, which comprises a plurality of rollers, a plurality of chain sheets and a plurality of chain rollers. Wherein the rollers define a mounting space. Each chain sheet comprises a chain body, a first pivot joint part extending from one end of chain body and to be arranged in the mounting space, a second pivot joint part horizontally extending from the other end of chain body, the second pivot joint part is installed on the roller with the first pivot joint part, wherein the first pivot joint part is in a horizontal position different from chain body, the first pivot joint part defines a rotation space for placing the second pivot joint part of another chain sheet, so that the first pivot joint part and second pivot joint part can rotate a preset angle in the rotation space. When the chain sheets are combined with rollers respectively, the chain bodies remain on the same plane, the chain roller penetrates the second pivot joint part and the first pivot joint part respectively for connecting the roller to the chain sheets on both sides of roller. Thereby, the chain is thinned and the weight is reduced, the tensile strength is increased by thickening the chain sheet.