How should cargo be balanced and distributed in a two-wheeled cart (carretela de dos ruedas)?

1. All weight placed at the very rear to lift the horse off the ground
2. Weight distributed evenly over the axle with a slight forward bias (approximately 5 to 10% of weight resting on the saddle/backband), ensuring the shafts do not lift the horse up or push excessively down on the horse's spine
3. Stacked as high as possible on one side only
4. Cargo should be tied to the horse's tail