| 摘要 |
<p>A structure is disclosed which enables easy manufacture of a supporting portion for a bicycle fork stem. This structure comprises: (i) a head pipe which is formed from a tubular pipe having a constant diameter and which has ball bearing accommodating portions each located at a position interior to an opening end of the head pipe relative to an axial direction, and (ii) ball bearings each of which has steel balls and first and second rings for holding the steel balls therebetween and supports the fork stem passing through the second ring. The ball bearing accommodating portions are each composed of (i) a support ring supported in a push-in inhibited fashion by an annular face that is formed on the inner circumferential surface of the head pipe so as to be perpendicular to an axial direction and (ii) one of the ball bearings with the first ring being supported in a push-in inhibited fashion by the support ring. <IMAGE></p> |
