Mildly technical rocky sections, smooth flowy turns, tree weaving, straight, fast, ridge-top speed... Backbone has it all. It's all singletrack with a few sections of doubletrack. No fire roads... AT ALL.
The terrain is classic Santa Monica mountain; crumbling rock and shale chips, large amounts of coastal and desert plant life, the smell and feel of the ocean nearby. The views of the ocean are stunning, and on clear days, the ring of mountains around SoCal can be seen clearly, along with great views of downtown LA and Hollywood.
From the top of Inspiration Loop Trail
, within the grounds of Will Rogers State Historic Park, you'll find a kiosk standing post beside an uphill singletrack, branching north around a hillside. The trail is narrow, so be sure to slow or stop for the large amount of hikers in the first mile. DO NOT BOMB THE HIKERS ON THE WAY BACK DOWN! The local community is wary of bikes here and are easily upset by your passing. BE RESPECTFUL. There are those who would like to ban us from the park.
After a tough climb, one mile from the kiosk, a bridge spans a particularly bad part of the ridge line. By law, you must walk your bike across the bridge and up the steep rock face just beyond it. (I know a guy who says he saw a ranger at the top watching one day)
About 1.5 miles up trail from the bridge there's a left-hand bend in the trail and a large oak tree near a drop-off. Under the shade of its branches is a large space and, with a commanding view of the valley beyond, is a great place to take a break.
What follows is roughly a mile of very pleasant, easy slope in the shade, to a mixed section of ups and downs, to a butt-kicking mile-plus of loose-pebble, rut-divided, sun-exposed slope from hell. Just when you've had enough, it ends. A short, steep downhill bends left, to the west, along the base of a left-hand hillside. Now in the shade, the trail takes on a different feel. There are more plants, and the dirt is darker, softer, and for about 3/4ths of a mile the trail is flat and easy. The trail narrows to a left-hand corner and to a sign "Backbone Trail - the hub" pointing left. This last section is super fun. Full of tight turns and thin tree trunks, it has a very nice flow. Too bad it's only a half-mile.
Well, that's it. The trail dumps out onto a wide, boring fire road, Temescal Ridge Trail, that spans away left and right. These connect to many other roads in the area and can be combined to form very long loops, but that's another day.
Turn around and re-trace the trail back to the car, but remember: DON'T BOMB THE HIKERS!!!