A bogie of a railway vehicle, in particular for a low floor tram, comprising of the following: - two pairs of wheels, the wheels of each pair being connected to each other by an axle structure, said axle structure comprising, for each wheel of the corresponding pair, an axle box, and - an articulated chassis, each axle structure being supported by the chassis by way of the primary suspension means, and wherein the primary suspension means includes the following: - for each wheel, an arm extending substantially longitudinally between a first end that is integrally joined with the axle box associated with this wheel, and a second free end, the arm being articulated between its first and second ends about a pivot connection with the chassis, and - for each arm, a primary helical spring extending between a first seat provided on the second end of said arm, and a second seat carried by the chassis, and wherein the chassis includes: - two lateral rails, each carrying at least the second seat for one of the primary helical springs, characterized in that the chassis also includes: - a chassis front cross bar extending transversely between the lateral rails, and - a chassis rear cross bar extending transversely between the lateral rails, and wherein: - the chassis front cross bar is integrally attached to a first rail among the lateral rails, and the rear cross bar is articulated about a pivot connection with this first rail, with an axis parallel to a general direction in which this first rail extends, and - the chassis rear cross bar is integrally attached to a second rail among the lateral rails, and the front cross bar is articulated about a pivot connection with this second rail, with an axis parallel to a general direction in which this second rail extends. - two pairs of wheels, the wheels of each pair being connected to each other by an axle structure, said axle structure comprising, for each wheel of the corresponding pair, an axle box, and - an articulated chassis, each axle structure being supported by the chassis by way of the primary suspension means, - for each wheel, an arm extending substantially longitudinally between a first end that is integrally joined with the axle box associated with this wheel, and a second free end, the arm being articulated between its first and second ends about a pivot connection with the chassis, and - for each arm, a primary helical spring extending between a first seat provided on the second end of said arm, and a second seat carried by the chassis, - two lateral rails, each carrying at least the second seat for one of the primary helical springs, - a chassis front cross bar extending transversely between the lateral rails, and - a chassis rear cross bar extending transversely between the lateral rails, - the chassis front cross bar is integrally attached to a first rail among the lateral rails, and the rear cross bar is articulated about a pivot connection with this first rail, with an axis parallel to a general direction in which this first rail extends, and - the chassis rear cross bar is integrally attached to a second rail among the lateral rails, and the front cross bar is articulated about a pivot connection with this second rail, with an axis parallel to a general direction in which this second rail extends.