Pfeiffer Big Sur State Park has beautiful hiker/biker sites among the redwoods. Unfortunately, the park is closed right now. (Storm damage? I don't remember.) Check
here for updates.
Kirk Creek Campground has beautiful hiker/biker sites amont grees on the bluff overlooking the ocean.
San Simeon State Park has a hiker/biker site that's not very pleasant. Everyone shares the same grassy spot (very lumpy ground) and 2 tables. It's right next to Highway 1, and you're in full view of all the other campers in this loop (the least desirable loop.) The good news is that there are showers.
Morro Bay State Park has very nice hiker/biker sites among eucalyptus trees on the edge of the campground. There are showers. Each hiker/biker has its own table.
That's all I know.