Abstract: 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.

Abstract: 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.

Abstract: A bearing assembly includes a head tube (10) through which a steerer tube (21) of the front fork (20) extends. A first annular flange (45) and a second annular flange (53) extend from an inner periphery of the head tube. An upper bearing (44) and a lower bearing (52) are respectively received in two ends of the head tube and contact the first annular flange and the second annular flange. A first ring (43) and a second ring (50) are respectively received in the head tube and press on the two bearings. A cap (41) is securely mounted to the steerer tube and compresses on the first ring and the second ring is positioned on a crown portion of the front fork.

Abstract: In a handle stem fixing device in a bicycle wherein a fork stem 10 is rotatably inserted into a head pipe 20 of a frame 2, the upper portion of the fork stem 10 projects out from the upper end of the head pipe 20 and, a stem-binding cylinder 30 is fixed on the upper portion of the fork stem 10 so as not to rotate. Many small protrusions are formed on the outer surface of the fork stem 10 where is pressed by the stem-binding cylinder 30. The coefficient of friction between contact surfaces of the fork stem 10 and the stem-binding cylinder 30 increases because of the protrusions. The coupling power acting between the fork stem 10 and the stem-binding cylinder 30 can thus be improved.

Abstract: A cover faces an end portion of a ball head cup attached to an end of a head pipe and is fitted on a fork stem. A rolling ball group is interposed between the ball head cup and the cover. A top cone is put on the rolling ball group from the cover side. The cover is formed of rubber or an elastic synthetic resin. The outer periphery of the cover is configured to be in contact with the inner periphery of the ball head cup. A cone ring inserted in the top cone and having a slit in its side wall is attached in the cover. Thus, the cover prevents the invasion of rainwater etc. through the slit of the cone ring.

Abstract: A handle stem fixing device in a bicycle includes a stem-binding cylinder 30 fitted on an upper portion of a fork stem 10 and a screw cap 4 engaged with an upper portion of the fork stem 10, wherein a thread is formed on an outer surface of the fork stem 10, and the screw cap 4 has a bore with internal thread. The cap 4 can be engaged with the thread of the fork stem when the upper portion of the fork stem 10 projects out from an upper end of the stem-binding cylinder 30. While the screw cap 4 is tightened, the 10 stem-binding cylinder 30 is depressed in an axial direction thereof by the cap 4 and is fixed on the upper portion of the fork stem 10.

Abstract: In a handle stem fixing device in a bicycle wherein a fork stem 10 is rotatably inserted into a head pipe 20 of a frame 2, the upper portion of the fork stem 10 projects out from the upper end of the head pipe 20 and a stem-binding cylinder 30 is fixed on the upper portion of the fork stem 10 so as not to rotate. Many small protrusions are formed on the outer surface of the fork stem 10 where is pressed by the stem-binding cylinder 30. The coefficient of friction between contact surfaces of the fork stem 10 and the stem-binding cylinder 30 increases because of the protrusions. The coupling power acting between the fork stem 10 and the stem-binding cylinder 30 can thus be improved.

Abstract: A bicycle handle consists of a horizontal bar-binding cylinder provided on a handle stem, a pair of handle bars fixed in both ends of the bar-binding cylinder and one or two pressure cylinders holding the handle bars. A through hole perforated in the pressure cylinder inclines from an axis of the bar-binding cylinder. Each handle bar has a handle grip at an end of it. The handle, bars are inserted into the pressure cylinder. When the pressure cylinder alone rotates, since a slanting direction of the through hole is changed, an projecting angle of the handle bar inserted into the through hole from the bar-binding cylinder is changed. So a position of the handle grip can be changed easier.

Abstract: A bicycle handle consists of a horizontal bar-binding cylinder provided on a handle stem, a pair of handle bars fixed in both ends of the bar-binding cylinder and one or two pressure cylinders holding the handle bars. A through hole perforated in the pressure cylinder inclines from an axis of the bar-binding cylinder. Each handle bar has a handle grip at an end of it. The handle bars are inserted into the pressure cylinder. When the pressure cylinder alone rotates, since a slanting direction of the through hole is changed, an projecting angle of the handle bar inserted into the through hole from the bar-binding cylinder is changed. So a position of the handle grip can be changed easier.

Abstract: A bicycle having post couplings, e.g., a coupling of a handle post to a binding cylinder of a handle clamp, and a coupling of a seat post to a binding cylinder of a frame. The binding cylinder has an extension formed on a side of it. Two slanting holes perforate the extension in slanting directions toward the inner cylindrical opening of the binding cylinder. Two skew blocks are inserted into the respective slanting holes so that the ends touch the post member. The bolt penetrates bolt bores formed in the skew blocks. A nut is fitted to an end of the bolt and tightened. As the nut is tightened, the skew blocks move in the slanting direction of the holes to secure the post member. Since the direction of separation of the skew blocks deviates from that of the axis of the bolt, the friction between the blocks and the slanting holes resists vibrational forces tending to loosen the coupling.