Which component does not need adjustment when carrying a passenger?

When carrying a passenger on a motorcycle, the taillight does not require adjustment. The taillight is designed to function effectively regardless of the load the motorcycle is carrying, as it is intended to illuminate and signal to other road users. The visibility provided by the taillight remains consistent, as it is mounted at a fixed location on the bike and does not shift based on the weight distribution or the presence of a passenger.

In contrast, the other components mentioned may need adjustment to ensure safety and optimal performance. For instance, the headlight may need minor adjustments to maintain visibility, particularly if the added weight of the passenger alters the bike's angle or height. Tire pressure is crucial to accommodate the additional weight; properly inflated tires ensure balanced handling and stability. Lastly, mirrors may also need to be adjusted to provide an unobstructed view of the road and surrounding traffic when a passenger is on board, as their presence can change the motorcycle's dynamics and blind spots.