Roller for a sliding panel assembly, and method of installing a sliding panel assembly

A roller for sliding a movable panel, the roller comprising:

• a housing;
• a plurality of wheels positioned within the housing, wherein the housing is configured to be positioned in a space defined between a bottom surface of the panel and a channel configured to receive a guided edge of the panel, the plurality of wheels comprising a first pair of wheels and a second pair of wheels, and the plurality of wheels being surrounded by compartments such that each said wheel is provided within a separate one of said compartments;
• wherein the housing further comprises a horizontally extending cross-piece, which is separate from the compartments, extending between the first pair of wheels and the second pair of wheels;
• and
• a vertically extending cross-piece, which is separate from the compartments, extending perpendicular to the horizontally extending cross-piece and between the first pair of wheels, wherein the first pair of wheels are mounted on a first axle and the second pair of wheels are mounted on a second axle.