What allows the U-Joint to flex?

The U-joint, or universal joint, allows for flexibility through its cross-shaped design, which connects two shafts at an angle. It consists of two yokes and a central cross, enabling it to accommodate angular misalignments while transmitting torque. The needle bearings within the U-joint provide smooth movement and reduce friction, allowing for the necessary flexing without significant wear. This design is crucial for applications in vehicles and machinery that require movement in multiple directions.