Bicycle transmission

An improved bicycle transmission of a type having a housing with a pair of walls, a primary axis mechanically driven by bicycle pedals and containing primary gears, a splined shaft being parallel to the pair of walls of the housing and having at least one gear and a meshing gear ganged together forming a primary group being movable along the splined shaft, and an independent gear being normally not mechanically connected to the splined shaft but receiving the meshing gear and mechanically connecting the independent gear with the primary group, an intermediate axis having intermediate gears mechanically driven by at least one primary gear, a final axis driven by at least one intermediate gear and being mechanically connected to a bicycle drive wheel, and shifting apparatus moving the gears along at least one of the primary axis and the final axis to vary which gear on that axis meshes with which gear on the intermediate axis and having a shifting shaft being vertically-oriented, a gear cover engaging the sides of the gears, a shifting arm extending horizontally-outwardly from the shifting shaft and moving the gear cover along the axis with a range of motion, and a locking apparatus maintaining the shifting arm in its position after it has been moved into a suitable position and having a spring extending therefrom to the housing and biasing the locking apparatus against the shifting arm, said improvement comprising the locking apparatus comprising a plate being vertically pivotally attached above, and selectively engaging and locking, the shifting arm.