Just like replacing worn-out handlebar tape with new tape that offers improved control and comfort, as seen in a road bike handlebar tape replacement guide, regular maintenance is key to extending the life of your bike parts. Replacing your road bike’s bottom bracket largely depends on mileage and conditions.
Consider replacement annually, or every 3,000 to 5,000 miles, especially if you ride in harsh environments.
Maintenance practices also influence frequency (Source).