An imaging system includes a steering roller and a positioning mechanism. The steering roller extends along a longitudinal direction, and being tiltable about a fulcrum to adjust an alignment position of an endless belt. The positioning mechanism is coupled to the steering roller, to position an adjustable position of the fulcrum of the steering roller, along the longitudinal direction of the steering roller. The positioning mechanism includes a guide that extends along the longitudinal direction of the steering roller, and a protrusion that engages with the guide, and that is located at the adjustable position of the fulcrum.