I rode this area a couple of weeks ago with
a group from the South Bay Riders forum, and it was a lot of fun. I did it on a WR250R, but there were also plenty of bigger adventure bikes as well. We did the route that Alex mentioned above - started at Bixby Bridge then dumped out on Hwy 1 at Molera. Then we rode south and did a variety of roads down by Mill Creek, Plasket, and Gorda.
Here are the tracks that we more or less explored.
The south part alone is a day worth of riding and exploring. It was a Saturday and Hwy 1 was busy with tons of people pulling in and out of beaches and lookout points. By the time we got back to Bixby Bridge, there were so many people parked there I could barely load up my bike and get out of there!