Mechanically interlocked spline for crank and bottom bracket interface of a micromobility vehicle

A micromobility vehicle, comprising:

• a frame;
• two wheels rotatably coupled to the frame;
• and
• a bottom bracket assembly located in the frame, the bottom bracket assembly comprising:
• an axle rotatable around a longitudinal axis, each end of the axle comprising:
• a plurality of angled surfaces, the plurality of angled surfaces defining an axle perimeter;
• and
• a recess formed in at least a portion of the axle perimeter;
• a pair of crank arms respectively associated with each end of the axle, each crank arm comprising:
• an axle opening formed at a first end of the crank arm, the axle opening comprising a base surface defining an axle opening base perimeter greater than the axle perimeter for positioning the crank arm on the axle;
• and
• a bore formed at an angle orthogonal to the axle opening, the bore having a radius which intersects at least the axle opening base perimeter and the axle perimeter, wherein the bore is aligned with the recess when the crank arm is positioned on the axle;
• and
• a fastener configured to be positioned in the bore, the fastener having a radius less than the radius of the bore such that at least a portion of the radius of the fastener is positioned radially inward of the axle perimeter along the recess when the fastener is positioned in the bore so as to resist withdrawal of the crank arm from the axle,
• wherein at each end of the axle:
• the plurality of angled surfaces comprises a plurality of external splines;
• the plurality of external splines defines an axle major radius, an axle minor radius, and an axle pitch radius;
• and
• the recess is formed with a depth through at least the axle major radius.

A method for interconnecting a bottom bracket assembly for a micromobility vehicle having a frame and a bottom bracket mounted in the frame, the method comprising:

• positioning a crank arm on an axle forming part of the bottom bracket, wherein:
• the axle comprises:
• a plurality of angled surfaces defining an axle perimeter;
• and
• at least two recesses formed in at least a portion of the axle perimeter, the at least two recesses being separated from each other along a longitudinal direction of the axle;
• the crank arm comprises:
• an axle opening formed at a first end of the crank arm, the axle opening comprising an internal surface defining an axle opening base perimeter;
• and
• at least two bores each formed at an angle orthogonal to the axle opening, each bore having a radius which intersects at least the axle opening base perimeter;
• and
• respectively aligning the at least two bores with the at least two recesses;
• and
• respectively positioning at least two fasteners in the at least two bores, wherein at least a portion of each fastener is positioned radially inward of the axle perimeter.