Lawn mower with a dual-tubular frame

A riding lawn mower comprising:

• a cutting deck housing a cutting blade;
• an engine;
• a deck drive coupled to the engine to receive power for operating the cutting blade;
• a ground drive coupled to the engine to receive power for movement of the riding lawn mower over ground;
• and
• a frame coupled to the cutting deck and providing structural support for the riding lawn mower, the frame comprising at least a first tubular structure and a second tubular structure, the first and second tubular structures extending substantially parallel to each other and to a longitudinal centerline of the riding lawn mower, wherein the first and second tubular structures each comprise:
• a seat bracket portion extending in a first plane,
• a first curved portion forward of the seat bracket portion, wherein the first curved portion extends out of the first plane,
• a second curved portion rearward of the seat bracket portion, wherein the second curved portion extends out of the first plane,
• a first frame projection extending forward from the first curved portion and seat bracket portion in a second plane, and
• a second frame projection extending rearward from the second curved portion and seat bracket portion in a third plane, to provide flexion of the frame, wherein the engine is mounted to the second frame projection, such that the engine is disposed rearward of the seat bracket portion.