Bicycle sprocket lock

A bicycle sprocket lock assembly in combination with a bicycle frame member and a sprocket, said assembly comprising

• a rod member adapted for sliding engagement through a first hole formed in said bicycle frame member adjacent to and in a direction normal to a plane of said sprocket of the bicycle, the rod member being of a sufficient length to be retained in the first hole and simultaneously passed at least partially through an opening in the sprocket, a second hole being formed in the frame member and oriented perpendicular to and offset from the first hole, said offset being one-half a diameter of the first hole, said rod having a pair of axially spaced, arcuately shaped slots formed transversely thereacross with a radius corresponding to a radius of the second hole, and
• an U-shaped shackle and cylinder lock adapted for attachment to the bicycle frame by passing one arm of the U-shaped shackle through the second hole,
• whereby the rod is attached to the bicycle frame and is adapted to be maintained in either an extended locked or withdrawn unlocked position with respect to the sprocket by alignment of a respective one of the shaped slots of the rod with the second hole prior to passing the one arm of the shackle through the second hole and fastening the shackle to the cylinder.