Abstract: An improved stem for a bicycle comprises an adaptor including a ring portion for securing onto a front fork, and a toothed section; a movable member having one end provided with a locking hole for securing to said ring portion, and another end provided with a toothed section; and a lateral tube having one end provided with a clamp member for securing a handle and another end provided with two toothed sections respectively at both sides thereof for meshing with the toothed section of the adaptor and the toothed section of the movable member after the lateral tube is adjusted to a desired angle.

Abstract: A bicycle stem having a positioning mechanism for re-positioning a handle comprises a vertical tube; an adaptor having a bore and an extension, wherein the bore receives therein the vertical tube so that the adaptor can rotate about the vertical tube; a lateral tube with a front end having a clamp for locking the handle, and a rear end pivotally connected to the extension of the adaptor; and a positioning mechanism comprising a rod for fixing the adaptor on the vertical tube as the adaptor is rotated to the required position about the vertical tube.

Abstract: An adjustable stem for a bicycle comprises a vertical tube; a lateral tube having one end pivotally connected to the top end of the vertical tube and a lateral channel in the interior thereof; a push rod disposed within the lateral channel; an engaging block disposed at one end of the lateral tube; and a quick-release mechanism which allows the engaging block to movably push the top of the vertical tube and one end of the push rod so that the other end of the push rod tightly contacts the bicycle handle.

Abstract: A stem for a bicycle comprises a lateral tube having one end provided with two toothed sections respectively at both sides thereof, and another end provided with a clamp member for securing a handle; an adaptor including a ringed clamp having a recess and a connecting rod laterally secured onto the ringed clamp, the recess being used for securing onto a front fork; and a left fixing member and a right fixing member of substantially the same shape and structure as the left fixing member, the fixing members each having one end provided with a locking hole for securing the fixing members to two ends of the connecting rod, respectively, and another end provided with a toothed section for meshing in engagement with the tooth sections of the lateral tube, respectively.

Abstract: A gap mechanism for a bicycle seat post comprises an outer tube having a hollow portion, an inner tube inserted into the hollow portion, and an intermediate (cushioning) sleeve disposed in the inner wall of the top portion of the outer tube and between the inner tube and outer tube, for clamping the inner tube, the intermediate sleeve being of a polygonal shape wherein the surface of a side thereof is provided with a stop member of a rigid material, thereby a bolt is provided, the end of the bolt abutting against said stop member so that the sides of the intermediate sleeve press tightly against the inner wall of the outer tube.

Abstract: A ball positioning structure on which a ball is placed comprises a lower body; an upper body placed on the lower body; a slide device provided in between the lower body and the upper body such that the lower body and the upper body are mutually rotatable; and a plurality of supports each having a top end and a bottom end, the bottom end being disposed on the surface of the upper body to define a receiving space for placing a ball.

Abstract: A handlebar for two-wheeled vehicle has a channel portion and two bent internal tubes wherein the channel portion has an internal diameter and the two bent internal tubes each have an external diameter slightly smaller than the internal diameter of the channel portion, the two bent internal tubes being disposed within the hollow portion with surfaces of the bent internal tubes in contact with the surface of the channel portion, whereby the thickness of the handlebar is increased in order to enhance the strength thereof.

Abstract: A handlebar for two-wheeled vehicle has a channel portion and two bent internal tubes wherein the channel portion has an internal diameter and the two bent internal tubes each have an external diameter slightly smaller than the internal diameter of the channel portion, the two bent internal tubes being disposed within the hollow portion with surfaces of the bent internal tubes in contact with the surface of the channel portion, whereby the thickness of the handlebar is increased in order to enhance the strength thereof.

Abstract: A ball positioning structure on which a ball is placed comprises a lower body including a round disk with a through-hole in the center thereof, an upper body covered on the lower body and having a bore provided in the center thereof which is in alignment with the through-hole; a bearing disposed in the bore of the upper body such that the upper body and the slide device are mutually rotatable, and a frame, on which a ball is placed, disposed on the surface of the upper body. A user may sit on the ball, press the ball, or lean on the ball and make fixed-point rotation to enhance enjoyment of playing.

Abstract: A stem of a bicycle having an iron member, said stem being made of aluminum and adapted to be fixedly secured to a fork and to clamp a handlebar, comprises a block including a sleeve provided at one end thereof for insertion of the fork of a bicycle and a base provided at the other end thereof, said base defining a semicircular surface; a cover having a semicircular surface which, together with the semicircular surface of the base close around and clamp the handlebar when the cover is secured to the base; and at least one iron member having a semicircular configuration and an inner surfaces and an outer surface, the outer surface being disposed on at least one of the two semicircular surfaces so that the iron member rather than the two semicircular surfaces contacts the handlebar whereby scraping of the at least one of the two semicircular surfaces by the handlebar is prevented.

Abstract: An improved stem for a bicycle comprises a column member having a top end, a first pivot mechanism and a second pivot mechanism which are provided on the two sides of the top end respectively; a sleeve member for fixing a handlebar, having a rod therefrom which defines a third pivot mechanism and a fourth pivot mechanisms on the two sides thereof; respectively and a lateral member including a left connecting part and a right connecting part wherein each of the left and right connecting part has two ends each having a protruded engaging mechanism adapted to be pivotally attached to the first, second, third and fourth pivot mechanisms so that the lateral member can be pivotally adjusted through the first and second pivot mechanisms, and the sleeve member can be pivotally adjusted through the third and fourth pivot mechanisms.

Abstract: An improved stem for a bicycle comprises a pivot member having a lateral member and a locking member attached to the underside of the lateral member, wherein the pivot member has two free ends each having a pivot portion and the locking member has two free ends as well; a column member having a first connecting mechanism at the top thereof for pivotally connecting to the pivot portion; and a sleeve member securing a handlebar, and being provided with a second connecting mechanism at the free end thereof for pivotally connecting the other pivot portion of the pivot member, whereby the locking member can be operated to move so that each free end thereof is fixedly attached to or detached from the first connecting mechanism and the second connecting mechanism so as to achieve the adjustment of the angle between the column member and the pivot member, and the angle of the handlebar, at the same time.

Abstract: An adjustable stem member comprises a vertical tube having a projected portion at one end thereof and a horizontal tube to be rotatably pivoted to the projected portion through a connecting mechanism at one end thereof. The connecting mechanism includes two tubular walls, an end wall and a space defined by the tubular walls and the end wall. A lower locking mechanism includes an upper locking block, a locking block and a bolt. The locking blocks are suitably disposed within the space. When the horizontal tube is adjusted to a suitable angle, the locking blocks are forced to press the end wall of the horizontal tube and the projected portion of the vertical tube.

Abstract: A locking mechanism comprises a bicycle fork tube which is rotatably received in a bicycle head tube. This fork tube has a plurality of elongate slots at its tubular wall below the top end portion. A stem member has a collar thereof which is removably enveloped around the top end portion of the bicycle fork tube. A tubular housing containing an actuating block and wedge members is removably received by the fork tube for retaining the stem member to the fork tube thereof.

Abstract: A stopper device comprises a rod member having a diameter which is the same as the outer diameter of the free end of the auxiliary handlebar. The rod member further includes a fastening shaft attached to the lower end portion of the rod member. The fastening shaft can be inserted into the free end of the auxiliary handlebar securing the rod member thereof. A supporting rod member is angularly formed on the upper end of the rod member and provides a solid support to the thumb of the rider.

Abstract: An improved stem mechanism, comprises a vertical bar having an upper portion and a inclined lower portion, the inclined lower portion is capable of being inserted into a fork member and with an annular portion at its inclined lower end; a bar member, angularly connected to the upper portion of the vertical bar; a securing member with an inclined upper end and with an annular portion thereon, the securing members is capable of being engaged firmly within the fork member and having a threaded passage in its lower end; and a bolt member having a threaded portion, which can be inserted into the vertical bar and form a firm engagement with the securing member; characterized by further comprising a washer having its outer wall portion engaged with the inner wall of the inclined lower end of the vertical bar and having its lower surface in line with the annular portion of the of the vertical bar so as to enlarge the area of the annular portion and improve the rigidity of the vertical bar in the inclined lower end th