A bicycle shifter configured to be adjustable to accommodate a variety of sized hands. The shifter includes a housing, a cable spool for pulling and releasing a control cable, pull and cable release lever mechanisms and a clamp for mounting the shifter to a handlebar. The cable pull lever mechanism includes a cable pull lever and a driver element operatively connected to the cable spool. The release mechanism includes a cable release lever. The cable pull lever is attachable to the driver element at various orientations to vary the position of the cable pull lever relative to the cable release lever. The clamp is attachable to the shifter housing at different positions to vary the pull and cable release levers relative to the handgrip element on the handlebar.