Putting a motorcycle in neutral while going downhill can potentially be harmful, and it is generally not recommended. The reason for this is that when the motorcycle is in gear, the engine acts as a brake, providing resistance to the wheels and helping to control the speed.
When you shift into neutral, you disengage the engine from the drivetrain, which means the motorcycle loses the engine braking effect. Without engine braking, the motorcycle relies solely on its mechanical brakes (front and rear brakes) to slow down or stop. This can put additional strain on the brakes and may lead to overheating or premature wear of the brake components.
Furthermore, without the engine engaged, you lose the ability to quickly accelerate or respond to sudden changes in traffic conditions. This can compromise your safety and control over the motorcycle, especially in situations where you may need to accelerate to avoid hazards or maintain control in an emergency.
In summary, it is generally safer to leave the motorcycle in gear when going downhill, as it provides engine braking and better control over the vehicle.