Adjusting your mirrors before riding is crucial for ensuring you have proper visibility of surrounding traffic. Mirrors are essential for a biker's situational awareness, allowing you to see vehicles approaching from behind and to the sides. Properly adjusted mirrors can help prevent accidents by giving you an accurate view of the road conditions around you.
When your mirrors are set correctly, you can assess the traffic situation more effectively, which is vital for safe maneuvers such as changing lanes or turning. This visibility is particularly important on a motorcycle, where the rider is more exposed compared to driving a car. Without clear visibility, a rider could easily miss a vehicle in their blind spot, increasing the risk of collisions.
While the other options may seem relevant at a glance, they do not contribute to safety in the same direct way that proper mirror adjustments do. Cleaning mirrors is certainly useful, making a motorcycle look aesthetically pleasing is irrelevant to safety, and increasing speed does not relate to the practical necessity of visibility.