Abstract: The disclosed speed-change gear includes a fitting secured to the frame of a bicycle, a parallel link means having an outside link and an inside link whose one ends are pivotally connected to the fitting, a movable member pivotally connected to the opposite ends of the inside and outside links, a changeover frame rotatably secured to the movable member, which changeover frame carries a guide wheel and a tension wheel of a chain, and a cam means adapted to selectively move said movable member so as to shift the speed-change ratio by changing the position of said changeover frame to shift the chain to the desired step of a multi-step sprocket assembly of the bicycle. The cam means has a spring-biased cam rotatably mounted on a shaft connecting the outside link to the fitting, which cam rotates together with a wire-operated reel coaxially mounted on said shaft. The rotation of the cam actuates said parallel link means through a lever pivotally carried by a shaft connecting the inside link to the fitting.

Abstract: A bicycle frame comprises tubes closed at their ends and lugs for connecting the tubes to form the frame, which lugs are formed by die casting in dies in which the tubes are arranged so as to integrally surround the closed ends of the tubes by the die-cast lugs. The tubes are previously formed at their ends with tapered portions each extending from that corresponding to an extreme end of a boss of the lug surrounding the end of the tube toward an extreme end of the tube. The outer surfaces of the bosses of the die-cast lugs are in substantially constant outer diameter or slightly tapered, thereby, in conjunction with the tapered portions of the tube, eliminating stress concentrations at the extreme ends of the bosses of the lugs, and saving the amount of the die-cast metal resulting in light weight bicycles which can save driving power and cost of manufacture.

Abstract: A caliper brake for a bicycle comprising left and right caliper arms rotatably fitted to a pivot shaft and having at their ends brake shoes adapted to be urged against a rim of a wheel of the bicycle, a rocking arm having a base portion pivotally mounted to a frame of the bicycle between the caliper arms on the pivot shaft in a semi-fixed condition, and the rocking arm having at its end a through-hole, opposite to which the left and right caliper arms have bottomed holes, respectively, and a universal joint lever having at its middle portion a middle protrusive ball portion and at both its ends end protrusive ball portions, respectively, the middle protrusive ball portion fitting in the through-hole of the rocking arm, those end protrusive ball portions fitting in the bottomed holes of the left and right caliper arms, respectively, whereby the extent of the free gaps between the left and right brake shoes and the rim are maintained substantially equal.