A crank arm for a bicycle chainset is provided. The arm comprises means for varying crank length during rotation, whereby to gain mechanical advantage.

An adjustable crank assembly is provided. The adjustable crank assembly includes a crank arm having a surface with a plurality of notches, and a retention block that partially houses the crank arm and allows the crank arm to slide along an axis relative to the retention block. The retention block includes a clamping block and a locking pin, both of which being adapted to selectively engage the crank arm when the retention block is placed in a locked position, and a locking lever for transitioning between a locked position and an unlocked position. The locking lever provides a compressive force to the clamping block when placed in a locked position and a retracting force to the locking pin when placed in an unlocked position.

An adjustable crank assembly is provided. The adjustable crank assembly includes a crank arm having a surface with a plurality of notches, and a retention block that partially houses the crank arm and allows the crank arm to slide along an axis relative to the retention block. The retention block includes a clamping block and a locking pin, both of which being adapted to selectively engage the crank arm when the retention block is placed in a locked position, and a locking lever for transitioning between a locked position and an unlocked position. The locking lever provides a compressive force to the clamping block when placed in a locked position and a retracting force to the locking pin when placed in an unlocked position.

A pedal cycle apparatus is disclosed in which a foot of a medically incapacitated user thereof engages a pedal for moving the pedal orbitally about a rotational axis of a crank hub. The apparatus includes a crank arm having a proximal and a distal end, the proximal end of the crank arm being rotatable about the rotational axis of the crank hub. A fastener fastens the pedal relative to the crank arm at a selectively variable radial distance from the rotational axis of the crank hub. The arrangement is such that in use of the pedal cycle apparatus, the foot of the medically incapacitated user engages the pedal so that the pedal moves orbitally about the rotational axis of a crank hub. The pedal rotates about an axis of rotation which is disposed parallel to the rotational axis of the crank hub such that selection by the user of an optimum radial distance of the pedal from the rotational axis of the crank hub is permitted.

A pedal cycle apparatus is disclosed in which a foot of a medically incapacitated user thereof engages a pedal for moving the pedal orbitally about a rotational axis of a crank hub. The apparatus includes a crank arm having a proximal and a distal end, the proximal end of the crank arm being rotatable about the rotational axis of the crank hub. A fastener fastens the pedal relative to the crank arm at a selectively variable radial distance from the rotational axis of the crank hub. The arrangement is such that in use of the pedal cycle apparatus, the foot of the medically incapacitated user engages the pedal so that the pedal moves orbitally about the rotational axis of a crank hub. The pedal rotates about an axis of rotation which is disposed parallel to the rotational axis of the crank hub such that selection by the user of an optimum radial distance of the pedal from the rotational axis of the crank hub is permitted.

The present invention includes two rotatable sleeves, two springs, two pins, two plastic sleeves and a Z-shaped crank. The two springs are respectively disposed in the two rotatable sleeves. The two rotatable sleeves are respectively accommodated around corresponding left end and right end of the crank. One end of each of the two springs is abuttingly connected on an inner wall of one of the two rotatable sleeves and one other end abuttingly connected on an end wall of the crank. The two pins are respectively penetrated through the two rotatable sleeves and are insertingly connected on the crank. The two plastic sleeves are respectively accommodated around left and right ends of the crank to closely cover the two pins. Thus, the present invention not only provides a smooth and pleasant appearance, but also allows a pedal to a position parallel to a bicycle without affecting a boxing effect.

The present invention includes two rotatable sleeves, two springs, two pins, two plastic sleeves and a Z-shaped crank. The two springs are respectively disposed in the two rotatable sleeves. The two rotatable sleeves are respectively accommodated around corresponding left end and right end of the crank. One end of each of the two springs is abuttingly connected on an inner wall of one of the two rotatable sleeves and one other end abuttingly connected on an end wall of the crank. The two pins are respectively penetrated through the two rotatable sleeves and are insertingly connected on the crank. The two plastic sleeves are respectively accommodated around left and right ends of the crank to closely cover the two pins. Thus, the present invention not only provides a smooth and pleasant appearance, but also allows a pedal to a position parallel to a bicycle without affecting a boxing effect.

A triple connection-structured crank arm which can be applied to all types of conventional bicycles. The direction of the crank arm is adjustable throughout 360 degrees. When component crank arms are connected in a longer manner, speed can be utilized. In contrast, when the component crank arms are connected in a shorter manner, a corresponding bicycle can be utilized as an exercise bicycle.

A triple connection-structured crank arm which can be applied to all types of conventional bicycles. The direction of the crank arm is adjustable throughout 360 degrees. When component crank arms are connected in a longer manner, speed can be utilized. In contrast, when the component crank arms are connected in a shorter manner, a corresponding bicycle can be utilized as an exercise bicycle.

A bicycle driving device: a first socket coupled to a frame; a first crankshaft rotatably coupled to the inside of the first socket; a first left crank arm coupled to the left side of the first crankshaft; a first right crank arm coupled to the right side of the first crankshaft; a second socket coupled to the frame at a location spaced from the first socket; a second crankshaft rotatably coupled to the inside of the second socket; a second left crank arm coupled to the left side of the second crankshaft; a second right crank arm coupled to the right side of the second crankshaft; a left pedal arm pivotally coupled to an end portion of the first left crank arm and to an end portion of the second left crank arm, the left pedal arm having a left pedal coupling portion positioned on an end thereof to be closer to the front than the end portion of the first left crank arm; a left pedal rotatably coupled to the left pedal coupling portion; a right pedal arm pivotally coupled to an end portion of the first right crank arm and to an end portion of the second right crank arm, the tight pedal arm having a right pedal coupling portion positioned on an end thereof to be closer to the front than the end portion of the first right crank arm; and a right pedal rotatably coupled to the right pedal coupling portion.