The ride up Montebello is rather easy. It should take you about 35 minutes, unless you're a beginner, in which case 2 hours is a good time. Roadies have done it in 25 minutes, but do so by wearing Spandex, white road shoes and by still wearing those rainbow-tinted Oakley sunglasses that went out with minitrucks and mullets in the early 90's.
At the top of Montebello, the asphalt will run out and you will be warned as to the presence of Rangers With Radars by the all-telling brown gate with yellow lettering (e.g., MB04). Whenever entering such a gate, walk your bike, although you may still get a ticket for walking your bike in an area you're not supposed to, as noted on the sign covered with PO. Anyway, continue on the dirt road and you'll come to the first CIA/NSA secret radio antenna site. Keep going through some rolling fireroads to the next set of secret radio antennas. On the coast side you'll see a cool rock formations with some elaborate cairns, which are put up by the rangers and mean "15 MPH SPEED LIMIT," but also mean, "HORSES CAN CRAP WHEREVER THEY WANT AND OWNERS DON'T HAVE TO PICK UP AFTER THEM. ALSO, HORSES AND THEIR OWNERS ARE ENCOURAGED TO RIDE WHEN IT'S WET SO AS TO IMPRINT THE TRAILS WITH ANKLE-TWISTING HOOF PRINTS WHICH CAUSE WAY MORE DAMAGE THAN ANYTHING A BIKE RIDER COULD DO."
Anyway, keep going past the secret antennas...you'll come to a split. You can go either way. If you go left, you'll go by a backpacking camp. Either way will lead you to Montebello Road, which is a fireroad. To its left is a nice singletrack that leads you down to Canyon Trail. Turn right and ride about 1/4 mile until you reach Page Mill Road. Right before the pavement is a trail that goes up to the Montebello Open Space parking lot. Stay right through the lot and follow the White Oak Trail. It'll bomb down through some pretty rutted trail, courtesy of our equine friends and their immune-to-rangers riders. When you get to the next intersection, turn right. You'll climb up to Hwy. 35. Cross the road and go down to Horseshoe Lake.
Go through the Christmas Tree Farm. You'll end up going through Russian Ridge and Long Ridge OSP's. You'll cross Hwy. 35 again and end up in Saratoga Gap OSP. Follow that trail until you end up on the intersection of Hwy. 9 and 35. You can either zip down Hwy. 9 and do a hard left on Redwood Gulch, right on Stevens Canyon and back to the car. Or, you can go back on the Saratoga Gap Trail, cross Hwy. 35 again, to Long Ridge OSP, then up to the Grizzly Flat parking area. Bomb down Grizzly Flat, right on Canyon Trail and out to Stevens Canyon Road to your car. I usually bomb down Grizzly but go back up on Table Mountain, which is an easy/intermediate climb. At the sand pit I hit the Gap Trail again, go down Hwy. 9, left on Redwood Gulch, right on Stevens Canyon Road, and to my car. I usually go swim in the reservoir, which you're not supposed to, but I do anyway.
Take Foothill Expressway exit from Hwy. 280 in Cupertino. Head south until you hit the Stevens Creek Reservoir. As you pass the reservoir, notice a right turn that is Montebello Road. Keep going and park at Mt. Eden and Steven Canyon Road. Ride your bike back to Montebello Road and head up...