Patent ID: 7562604

Claim:
A bicycle chain wheel structure comprising: a right crank arm portion having a pedal mounting arrangement; an axle portion having a first end integrally formed with the right crank arm portion as a one-piece, unitary member and a second end with a crank arm mounting arrangement, the axle portion having external threads disposed between the first and second ends of the axle portion and an internal bore extending between the first and second ends; and a left crank arm detachably, non-rotatably mounted on the second end of the axle portion, the crank arm mounting arrangement of the second end of the axle portion including internal threads with a mounting bolt threadedly coupled thereto to axially retain the left crank arm on the second end of the axle portion, and a locking member threadedly coupled to the left crank arm, the locking member including a first surface facing radially inwardly which is opposed to a first surface facing radially outwardly of the mounting bolt, and the locking member further including a second surface facing radially outwardly which is opposed to a second surface facing radially inwardly of the mounting bolt such that the locking member covers an axially outwardly facing end surface of the mounting bolt.