This isn't a specific trail, but a route to complete a loop ride around La Jolla.
There aren't many bike trails in the area but there are bike lanes so you will find yourself along the side of a busy road in places. The route uses part of the beach trails and the Rose Canyon Trail. Easiest way to follow the route will be using the GPS track.
The ride along the ocean can be scenic but it was rather foggy the day I did it.
Directions:
There are a number bike rental places along Avendia de La Playa start from one of them.