It's been a while, but you could ride over Fremont Older to Stevens Canyon, then ride up Montebello Rd, across to Page Mill, then take Alpine road down to Foothill Expressway to head back toward San Jose.
Lots of options off Skyline in the multiple open space preserves: Sanborn/JNT, Gap/Stevens Canyon, Long Ridge, Russian Ridge, Skyline OSP Montebello, Alpine, Coal Creek, and Parts of Windy Hill.
If you are willing to come to Santa Cruz, there are many options in Wilder Ranch and the fire-road network in UCSC, and then the Forest of Nisene Marks has a nice long grind up the hill comprised of gravel.
