What factor greatly influences a motorcycle's handling?

The weight of the motorcycle's rider indeed plays a significant role in influencing the motorcycle's handling. The overall weight, including the rider and any cargo, affects the motorcycle's center of gravity, stability, and cornering capabilities. A heavier load can lead to slower response times when maneuvering, as the motorcycle may feel more sluggish and less agile.

Moreover, proper tire pressure is crucial to a motorcycle's performance and safety. It affects the contact patch between the tires and the road, impact on braking distances, and the overall stability of the motorcycle. When the tire pressure is optimized, it enhances grip, cornering stability, and helps maintain the motorcycle's intended handling characteristics. Maintaining the correct tire pressure is essential to ensure safe and predictable handling in various riding conditions.

Factors like wind speed and road surface conditions certainly can impact handling, but they don't play as direct a role in the intrinsic design and performance of the motorcycle itself as tire pressure does.