Patent ID: 8721187

Claim:
A bicycle crank axle assembly comprising: a crank axle including a first end portion having a plurality of external serrations provided on an outer circumferential surface of the first end portion of the crank axle, and an internal thread disposed on an inner circumferential surface of the first end portion of the crank axle, the crank axle defining a rotational axis; a first crank arm including a splined connecting hole non-rotatably engaged with the external serrations of the first end portion of the crank axle, the first crank arm being secured to the first end portion of the crank axle by a fastening bolt screwed in an axial direction into the internal thread of the first end portion of the crank axle; a first bearing including a first cone, a first cup, and a plurality of first roller elements, the first cone being disposed on the crank axle and the plurality of first roller elements being disposed between the first cone and the first cup such that the first cup rotates relative to the first cone about the rotational axis, the first cone contacting the roller elements along an entirety of an arc extending ninety degrees from a radially innermost point of the roller elements with respect to the rotational axis, and the first cup contacting the roller elements along an entirety of an arc extending ninety degrees from an axially innermost point of the roller elements with respect to the rotational axis; a first bearing adapter including a first tubular mounting section for mounting to a tubular member and a first bearing housing section housing the first bearing therein, the first bearing housing section having a first tapered abutment angled relative to the rotational axis at a first abutment angle that corresponds to an acute angle formed by an intersection between the rotational axis and an extension plane of the first tapered abutment and contacting a first tapered contact surface of the first cup; and a first conical element disposed on the crank axle, the first conical element having a tapered abutment surface angled relative to the rotational axis at a second abutment angle that corresponds to an acute angle formed by an intersection between the rotational axis and an extension plane of the tapered abutment surface of the first conical element and contacting a first tapered contact surface of the first cone, the first bearing being axially pressed by the crank arm axially moving the first conical element in response to the fastening bolt being screwed into the internal thread of the crank axle, the second abutment angle of the tapered abutment surface of the first conical element being smaller than the first abutment angle of the first bearing housing section, and the tapered abutment surface of the first conical element having a tapered outer end portion that extends outwardly in the axial direction along the crank axle from a first outer axially facing end of the first cone.