A bicycle includes a lower frame member and an upper frame member connected to a head tube. The lower frame member includes a down tube, a bottom bracket, and chain stays. The upper frame member includes a top tube, seat stays, and a passage formed in part by a first side wall and a second side wall. The first and second side walls include a first and second openings, respectively. A seat tube extends in an upward direction from the bottom bracket and through the passage. The seat tube includes an opening that extends laterally therethrough. A passive pivot assembly secures the seat tube within the passage, and includes a guide sleeve that extends through the first opening, through the opening in the seat tube, and through the second opening. One or more fasteners secure the guide sleeve to the upper frame member.

A crank arm for a bicycle may include a body extending along a body axis and having a first body end and a second body end axially spaced apart from the first body end. The insert may also include an insert provided toward the first body end. The insert may include a base portion having a radially outer surface. At least one extension may extend outwardly from the radially outer surface and may be encased within a corresponding recess in the body whereby relative planar movement between the body and the at least one extension in a first plane. The retaining portion may have a retaining portion width measured in the first direction and the retaining width may be greater than the throat width thereby inhibiting relative radial movement between the at least one extension and the recess and preventing radial extraction of the extension from the corresponding recess.

A crank arm for a bicycle may include a body extending along a body axis and having a first body end and a second body end axially spaced apart from the first body end. The insert may also include an insert provided toward the first body end. The insert may include a base portion having a radially outer surface. At least one extension may extend outwardly from the radially outer surface and may be encased within a corresponding recess in the body whereby relative planar movement between the body and the at least one extension in a first plane. The retaining portion may have a retaining portion width measured in the first direction and the retaining width may be greater than the throat width thereby inhibiting relative radial movement between the at least one extension and the recess and preventing radial extraction of the extension from the corresponding recess.

A main body frame (100) for an electric motorcycle comprises a front fork support member (101) with a front fork through hole for loading a pivot stem of a front fork (200), the front fork through hole has a pivotal axis arranged in a central plane (P) of the main body frame; the main body frame further comprises a right and a left frame part (102, 105) arranged on opposite sides of the central plane of the main body frame, each having an elongated shape and being formed of an upper part (102a, 102b) and a lower part (102c, 102d), respectively at different sides of an elongation direction changing portion (102e), a first buffer member (120) attached, at opposite sides thereof, to the right and the left frame part, and crossing the central plane. wherein starting from the respective elongation direction changing portions thereof. the upper parts of the left and the right frame part extend inwardly towards the central plane so as to embrace the front fork support member, and are attached to opposite sides of the front fork support member, and a largest width (a7) of the main body frame in a width direction (Z) perpendicular to the central plane is 10 cm or more and 30 cm or less.

A superefficient box beam bicycle structure (SBBBS) having a box section, a right triangular section and a left triangular section. The right and left triangular sections are either integral with the box structure, or the triangular sections are attached to the box structure by riveting, bonding or welding. The box structure is preferably made of a sheet material and the parts that comprise the box structure are attached together by riveting, bonding or welding. The SBBBS interfaces with conventional bicycle components to function as a lightweight, strong bicycle frame.

A superefficient box beam bicycle structure (SBBBS) having a box section, a right triangular section and a left triangular section. The right and left triangular sections are either integral with the box structure, or the triangular sections are attached to the box structure by riveting, bonding or welding. The box structure is preferably made of a sheet material and the parts that comprise the box structure are attached together by riveting, bonding or welding. The SBBBS interfaces with conventional bicycle components to function as a lightweight, strong bicycle frame.

An aerodynamic front fork assembly for a bicycle may include an elongated crown portion extending from a steerer tube to a distal end behind a front wheel, with one or more fork blades projecting in a generally forward direction from the distal end of the crown portion to engage the front wheel. The crown portion may substantially fill the gap between the front wheel and the down tube of the bicycle, thereby collectively forming an airfoil with the front wheel and the down tube.

A crank arm for a bicycle may include a body extending along a body axis and having a first body end and a second body end axially spaced apart from the first body end. The insert may also include an insert provided toward the first body end. The insert may include a base portion having a radially outer surface. At least one extension may extend outwardly from the radially outer surface and may be encased within a corresponding recess in the body whereby relative planar movement between the body and the at least one extension in a first plane. The retaining portion may have a retaining portion width measured in the first direction and the retaining width may be greater than the throat width thereby inhibiting relative radial movement between the at least one extension and the recess and preventing radial extraction of the extension from the corresponding recess.

A crank arm for a bicycle may include a body extending along a body axis and having a first body end and a second body end axially spaced apart from the first body end. The insert may also include an insert provided toward the first body end. The insert may include a base portion having a radially outer surface. At least one extension may extend outwardly from the radially outer surface and may be encased within a corresponding recess in the body whereby relative planar movement between the body and the at least one extension in a first plane. The retaining portion may have a retaining portion width measured in the first direction and the retaining width may be greater than the throat width thereby inhibiting relative radial movement between the at least one extension and the recess and preventing radial extraction of the extension from the corresponding recess.

To provide a moving device that can be used as a mobility device to transport objects and can be improved in portability. The moving device that is movable with rotation of wheels includes a body unit inflated by injection of fluid and deflated by discharge of the fluid, a support body provided on a predetermined surface of the body unit, and the wheels provided in the support body, wherein the interior of a predetermined portion of the body unit that receives a load from an object contacting the body unit is formed with a drop-stitch structure, and the drop-stitch structure after injection of the fluid has tensile forces in directions approximately perpendicular to the direction of the load applied to the predetermined portion by the object.