Abstract: The invention provides a bicycle crank unit in which the chain wheel or chain wheels are eccentric with respect to the crank spindle and the crank spindle carries an externally toothed pinion to engage within an internal gear carried coaxially by the chain wheel. This provides a step down gearing between the pedal crank arms and chain wheel and enhances the mechanical advantage of the drive transmission.

Abstract: A target pigeon is made of synthetic resins such as polystyrene and polymethacrylate which are not mutually soluble. The resins are heated and cooled successively prior to injection molding of the pigeon so that they coagulate together and form a mass of tiny flakes constituting the body of the pigeon. These resins are injected into the mold cavity at a plurality of locations so that the pigeon has interfaces constituting weak lines that allow it readily to disintegrate when struck transversely, but which do not decrease the longitudinal strength so the pigeon can be launched by means of an explosion from a blank cartridge or the like.