Why bicycle breaks don't work very well in the rain?

Bicycle brakes, particularly rim brakes, often struggle in the rain because water can create a film between the brake pads and the rim, reducing friction and braking power. Additionally, wet conditions can cause brake pads to become less effective, leading to longer stopping distances. Disc brakes can also be affected, but they typically perform better in wet conditions as they are less prone to water accumulation and have better heat dissipation. Overall, moisture reduces the effectiveness of braking systems, making it essential for cyclists to maintain a greater stopping distance in the rain.