What Causes the Rattling Sound in a Scooter's Variator?

[OAlice]

The reason is either worn-out variator rollers or improperly positioned rollers. In such cases, it should be disassembled for inspection. If the sound comes from the rear clutch, it is mostly due to uneven tension in the clutch shoes (usually accompanied by body vibration during acceleration). Below is more information about the variator: Structure: The transmission system has a belt connecting two discs. The outer disc is the fixed disc, while the inner disc is the variator (also called the movable disc, capable of axial movement). Variator Rollers: The variator rollers (also called movable rollers, capable of radial movement) are components inside the variator. There are six rollers, each installed in a sliding groove, and they are influenced by the engine's RPM. Impact on Gear Ratio: When the scooter accelerates, the engine RPM decreases. The variator rollers move radially toward the center, reducing the force with which the discs squeeze the belt. The belt moves toward the center of the disc, decreasing the diameter of the driving disc and increasing the diameter of the driven disc, thereby reducing the gear ratio.