I read Dylan's trip report yesterday, and it kick-started me to get around to posting a report of a bike trip we took that shared a little of his route.
(Dylan's report is here http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=62505)
A couple years ago, we wanted to visit the Carrizo Plain National Monument during wildflower season, so we pieced together a 450 mile dirt and quiet-pavement bike route loop. It was a great ride, and logistics were easy because it is a loop. It includes a few VERY short carry/hike-a-bike sections and a few miles that are gently technical. It's actually mostly paved, but nearly all the paved roads are very quiet. It passes three towns and a few isolated rural cafes. In my mind, the route is worth riding only when the Carrizo Plain is in full bloom (especially after a wet winter). Carrizo Plain in full bloom is a sight to behold, some claim it's perhaps the best wildflower show in the U.S. Bloom occurs in March-May, but exact timing depends on the timing of the winter rains.
Highlights of the trip include the Carrizo Plain, the closed-to-traffic road on the eastern border of the Ventana Wilderness in Los Padres National Forest, the very beautiful Oak Savannah ranch lands between Carrizo and Coalinga and then from Coalinga to Soledad, and the Valley Oak Savannah in Fort Hunter Ligget.
Link to annotated Photo Show. The first photo in the SmugMug album shows the route, and includes links to the gpx/kml files and wildflower info. (We were using panniers; we have since purchased bags from Carousel and Revelate that will let us ride without racks on our next trip.)