A ride-along vehicle may include a spring/chain guard that covers a spring and chain assembly and provides an attachment point for the spring. The guard may have a narrow portion that covers and helps retain the chain on a sprocket as well as a wider portion that covers the spring. In another embodiment, the spring can be connected to a fulcrum that has a chain retention pulley, gear, guide, or wheel that keeps the chain tight in loop to improve the pump-action operation of the vehicle. An improved pumper arm and steering mechanism may include a pivot joint that is provided by rods, pins, or bolts attached to opposite sides of the pumper arm. The universal joint between the steering arm and the pumper arm can be aligned with the center of the pivot point to prevent rocking of the steering arm as the pumper arm is actuated.

A ride-along vehicle may include a spring/chain guard that covers a spring and chain assembly and provides an attachment point for the spring. The guard may have a narrow portion that covers and helps retain the chain on a sprocket as well as a wider portion that covers the spring. In another embodiment, the spring can be connected to a fulcrum that has a chain retention pulley, gear, guide, or wheel that keeps the chain tight in loop to improve the pump-action operation of the vehicle. An improved pumper arm and steering mechanism may include a pivot joint that is provided by rods, pins, or bolts attached to opposite sides of the pumper arm. The universal joint between the steering arm and the pumper arm can be aligned with the center of the pivot point to prevent rocking of the steering arm as the pumper arm is actuated.

A crank assembly for a bicycle includes a crank axle rotatably mounted to a frame of the bicycle, and a carrier shaft slidably mounted on the crank axle and configured to slide in a direction substantially parallel to a central longitudinal axis of the crank axle and relative to the crank axle. The crank assembly also includes an elliptical sprocket mounted on the carrier shaft. The elliptical sprocket rotates to move the bicycle in response to a rotation of the crank axle. A start time of a power stroke of the elliptical sprocket is changed by sliding the carrier shaft relative to the crank axle.

A crank assembly for a bicycle includes a crank axle rotatably mounted to a frame of the bicycle, and a carrier shaft slidably mounted on the crank axle and configured to slide in a direction substantially parallel to a central longitudinal axis of the crank axle and relative to the crank axle. The crank assembly also includes an elliptical sprocket mounted on the carrier shaft. The elliptical sprocket rotates to move the bicycle in response to a rotation of the crank axle. A start time of a power stroke of the elliptical sprocket is changed by sliding the carrier shaft relative to the crank axle.

An actuation and traction system for a pedal-actuated electric vehicle like electric bicycle, electric tricycle, or electric quadricycle comprises an electric motor, a transmission comprising an epicyclic device and a variable speed drive actuated independently of the pedals wherein the variable speed drive comprises an actuator that discretizes the ratio, and two expandable pulleys wherein the transmission of the motion occurs through a cascade of gears adapted to obtain the desired transformation ratio between the electric motor that rotates at high speed, and the pinion that actuates the chain for transmitting motion to the wheel of the electric vehicle.

A chainring includes a first chainring segment and a second chainring segment for a chainring arrangement of a bicycle. Further provided is a chainring arrangement and a drive arrangement for a bicycle with at least one chainring. The segmented chainring arrangement is particularly suitable for bicycles with only one front chainring.

A chainring includes a first chainring segment and a second chainring segment for a chainring arrangement of a bicycle. Further provided is a chainring arrangement and a drive arrangement for a bicycle with at least one chainring. The segmented chainring arrangement is particularly suitable for bicycles with only one front chainring.

A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

A pulley for a transmission system, including a central rotatable hub having a circumference; and a plurality of adjoining identical pulley segments rotatably mounted about the central hub circumference, wherein the adjoining pulley segments form an approximately circular stepped pulley shape and each of the pulley segments includes two sections providing two curved shelf surfaces for engaging a flexible drive member, each shelf having a different radius, forming higher and lower steps, and further wherein each of the pulley segments are independently rotatable about a radial axis with respect to the central hub.