Abstract: Employing a set of open gears in a bicycle drivetrain allows disengaging the connection between the crank arms and the driven wheel. When the fold axis passes approximately through the mesh plane between the aforementioned gears, and said axis is offset from the center plane of the gears in the direction of the fold by at least one-half the gear width, by design even a small angular displacement around the fold axis opens instantly producing a gap between the gears that increases as the fold proceeds, thus breaking and disengaging the connection between the crank arms and driven wheel, thus leaving the displacement of the fold to complete its angular cycle without regard or interference from the newly separated drivetrain. In its folded configuration, the bicycle can roll backwards, forwards, and spin or pirouette on its own axis.

Abstract: This invention is an easily assembled and disassembled exercise dumbbell that derives the majority of its adjustable weight from the addition of monetary coins. The number of coins used determines the weight of the dumbbell, thereby making possible very small incremental increases in the dumbbell's effective total weight. The weight of the dumbbell's handle assembly can be multiplied up to nine times in its heaviest dumbbell configuration. Additional weight may be achieved with the use of small metal slugs. Due to the use of a specialized screw head, the dumbbell can be assembled and disassembled with only the use of a coin (no standard screwdriver is necessary). With all coins removed, this dumbbell makes an excellent lightweight travelling companion.

Abstract: The addition of a lockable second axis of crank arm rotation roughly parallel to the structural neutral axis of the crank arm enables a reduction in bicycle storage or shipping volume substantially more effectively and easily than current removable or folding pedal designs. This second axis passes through an adapter, one at each end of the bottom bracket. The adapter restricts any motion of the crank arm to normal pedaling or rotating the crank around the second pedal axis to a storage position. A locking key(s) and retainer prevent any inadvertent crank arm movement. This invention is not dependent on pedal design. Any standard pedal may be employed.

Abstract: Employing a set of open gears in a bicycle drivetrain allows disengaging the connection between the crank arms and the driven wheel. When the fold axis passes approximately through the mesh plane between the aforementioned gears, and said axis is offset from the center plane of the gears in the direction of the fold by at least one-half the gear width, by design even a small angular displacement around the fold axis opens instantly producing a gap between the gears that increases as the fold proceeds, thus breaking and disengaging the connection between the crank arms and driven wheel, thus leaving the displacement of the fold to complete its angular cycle without regard or interference from the newly separated drivetrain. In its folded configuration, the bicycle can roll backwards, forwards, and spin or pirouette on its own axis.