PURPOSE: To provide a hanger for a bicycle which is so constituted as to a chain line is easily adjusted even when the boss part of a cotterless crank arm to fix a chain sprocket to a taper angle shaft at one end is a hanger lug to pivotally support a crank shaft fastened by a fastening nut.

CONSTITUTION: The boss part 12 of a cotterless crank arm 11 to fix a chain sprocket 13 to a taper angle shaft 9 at one end is a hanger lug 2 disposed to the lower end of a frame 1 to pivotally support a crank shaft 4 fastened by means of a fastening nut 10. The outer peripheral cylinder 5 of a unit hanger 3 where a bearing consisting of a ball 6 and an outer peripheral cylinder 5 are brought into a unit and integrally disposed in the proper position of the crank shaft 4 is slidably fitted in the inner peripheral surface of the cylinder of the hunger lug 2, and the position in an axial direction of the unit hanger 3 based on the hunger lug 2 is adjustably fastened.