The disclosed embodiments include a drive structure. The drive structure includes a first sprocket and a second sprocket. Each of the first and second sprocket has a shape with two points and four sections of teeth where two sections of teeth are inline and two sections are curved. Attached to the first sprocket are slap crank arms, which contains a slap crank arm lever to move and cause an impact force when the first sprocket is rotated. A drive chain travels in a loop between the first sprocket and second sprocket. Embodiments of the drive structure include other elements of a bicycle frame and rear derailleur structure.

An all limb powered and steered front wheel drive land vehicle comprises a seat (133), a front wheel (115), a rear wheel (155), a front drive component (66) and a frame (1) wherein; the seat (133) and a rear wheel (155) are mounted on a rear portion of the frame (1); wherein the front wheel (115) and front drive component (66) are mounted on a front portion of the frame (1); wherein the front drive component (66) comprises a drive mechanism (61) for driving the front wheel (115) and a connecting rod (23)comprising two hand grips for driving the drive mechanism (61) and a lever (31) comprising two foot pegs for driving the connecting rod (23) and a fulcrum (105) mounting the lever (31) to the frame (1). Employing all four limbs of a comfortably seated rider for power and steering, this high performance bicycle converts into a tricycle by removing the rear wheel (155) and replacing it with an axle (192) and a left rear wheel (190) and a right rear wheel (191).

A bicycle crankset, which is adapted to connect to a chain, includes a chainring, a spider, and a crankarm. The chainring has teeth on an edge thereof to engage the chain and a chainring axis through a center thereof. The spider has spider arms to detachably connect to the chainring and a connecting bore. The spider has a core axis through a center of the connecting bore, and the core axis is kept a predetermined distance away from the chainring axis to form a deviation. The crankarm has an engaging member to engage the connecting bore of the spider. Tips of the teeth of the chainring move in a noncircular path when the crankarm is exerted to drive the chainring to turned, and the noncircular path is adjustable by shifting a location of the connecting bore which change the deviation.

A bicycle crankset includes a chainring, a spider, and a crankarm. The chainring has a disk member and a plurality of teeth on an edge of the disk member to engage a chain. The spider is connected to the disk member of the chainring, and has a connecting bore and a plurality of recesses on an edge of the connecting bore. The crankarm has a plurality of protrusions to engage the recesses of the spider. The connecting bore is eccentric relative to the chainring, and the crankarm is able to be connected to the chainring in different angles by engaging the protrusions of the crankarm with different of the recesses of the spider to provide various paths of motion of the chainring.

A bicycle crankset, which is adapted to connect to a chain, includes a chainring, a spider, and a crankarm. The chainring has teeth on an edge thereof to engage the chain and a chainring axis through a center thereof. The spider has spider arms to detachably connect to the chainring and a connecting bore. The spider has a core axis through a center of the connecting bore, and the core axis is kept a predetermined distance away from the chainring axis to form a deviation. The crankarm has an engaging member to engage the connecting bore of the spider. Tips of the teeth of the chainring move in a noncircular path when the crankarm is exerted to drive the chainring to turned, and the noncircular path is adjustable by shifting a location of the connecting bore which change the deviation.

A bicycle crankset, which is adapted to connect to a chain, includes a chainring and a crankarm. The chainring has a plurality of teeth, a plurality of connecting bores of first noncircular motion path, and a plurality of connecting bores of circular motion path. The crankarm has a plurality of connecting arms to be selected to secured to the connecting bores of first noncircular motion path or the connecting bores of circular motion path. The chainring provides a first noncircular path of motion when the connecting arms of the crankarm are secured to the connecting bores of first noncircular motion path, and chainring provides a circular path of motion when the connecting arms of the crankarm are secured to the connecting bores of circular motion path.

The gearwheel for motion transmission systems onto cycles is rotatable with respect to its center of rotation and comprises two gearwheel halves centrally symmetrical with respect to the center of rotation and both having a dragging profile adapted to enter at least partially in contact with a flexible element closed in a loop for the driving in motion of a cycle, with the dragging profile which comprises at least five sections having different curvatures between them and comprises a larger diameter and a smaller diameter whose ratio has a value between 1.31 and 1.39.

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 pully, 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 bicycle chainring includes a plurality of teeth extending from a periphery of the chainring wherein roots of the plurality of teeth are disposed adjacent the periphery of the chainring. The plurality of teeth include a first group of teeth and a second group of teeth, each of the first group of teeth wider than each of the second group of teeth. At least some of the second group of teeth are arranged alternatingly and adjacently between the first group of teeth, and wherein the periphery of the chainring is generally non-circular.

A reduction ratio changing device, so-called DCRR, for a mechanical chain transmission system includes a toothing. The toothing of the DCRR includes a portion, so-called the helical portion, forming a toothed helix winding around an axis of revolution of the DCRR and a portion, so-called the circular portion, forming a toothed planar circle whose centre coincides with the axis of revolution of the DCRR. The helical portion of the toothing extends from a distal end of the toothing of the DCRR towards the circular portion of the toothing. The circular portion of the toothing of the DCRR forms a proximal end of the toothing of the DCRR.