Abstract: A change-speed gearbox has coaxial input and output shafts. Five intermediate shafts are equi-spaced around the input shaft and each has two gears fixed thereto, one of which meshes with a common gear on the input shaft, the intermediate shafts being movable axially.Five gears of different diameters are fixed to the output shaft around which five secondary shafts are carried by a rotatable cage. The five secondary shafts each have two gears fixed thereto, one of which meshes with a different one of the gears on the output shaft.Any one of a possible twenty five gear ratios between the input and output shafts may be obtained by rotating the cage until a selected one of the secondary shafts is in the same radial plane as a selected one of the intermediate shafts, that intermediate shaft then being moved axially to bring the second gear thereon into mesh with the second gear on the selected secondary shaft.