Abstract: A variable speed mechanism includes a drive shaft, a plurality of drive gears each fixedly mounted around the drive shaft, a plurality of driven gears each respectively meshing with a corresponding one of the drive gears, a plurality of single direction needle bearings each fixedly mounted in a corresponding one of the plurality of driven gears, a driven shaft mounted in the plurality of single direction needle bearings, an elongated sleeve slidably mounted around the driven shaft, the elongated sleeve being slidable on the driven shaft between a first position where an enlarged free end thereof is fitted into a corresponding one of the single direction needle bearings such that the elongated sleeve is rotated by the associated driven gear, thereby rotating the driven shaft therewith, and a second position where the enlarged free end thereof is not in contact with any one of the single direction needle bearings such that the elongated sleeve and the driven gear stop rotating, a rack slidably mounted in parall

Abstract: A transmission apparatus is used in an electrical bicycle which includes a power switch, a rear wheel and a hub in the rear wheel. The transmission apparatus of the electrical bicycle includes an upper transmission set including a speed-reducing motor connected to a drive gear which is meshed to a driven gear, a middle transmission set including an upper rod, a lower rod, and a universal joint connected therebetween, where the upper rod is connected to the driven gear, and a lower transmission set including a first bevel gear extended from the lower rod, a second bevel gear meshing with the first bevel gear, a tube extended from the second bevel gear and received in the hub of the rear wheel, and at least one unidirectional needle bearing positioned between the hub and the extended tube allowing the extended tube to drive the hub to rotate thus moving the rear wheel forward yet not allowing the hub to drive the extended tube to rotate.