Why must both brakes on a motorcycle always be in perfect working order?

Both reasons provided in the correct answer are crucial for motorcycle safety and are in line with German traffic regulations.

Firstly, having both brakes in perfect working order ensures the shortest possible braking distance. This is vital for quick stops in emergency situations, minimizing the risk of accidents. Motorcycle braking systems are designed to distribute braking force across both front and rear brakes, which enhances stability and control during braking.

Secondly, in case one brake fails, the functioning of the second brake becomes essential. Riding with only one brake increases the risk of losing control, emphasizing the need for redundancy in the braking system.

While safely parking on a downhill slope is important, it does not directly pertain to the necessity for both brakes to function properly while riding, which is why it was not included in the correct combination. Adhering to these principles ensures compliance with road safety laws and contributes to overall road safety.