Sycamore Canyon has some really excellent cross country riding, and a few freeride areas, too. For the XC riders, there are several fun climbs, sometimes a little technical, with speedy singletrack descents, and a couple water crossings.
The freeride challenges are mostly at the southeast corner of the park, hidden away a bit. There is a teeter totter, numerous jumps, and some drops that are at least 15 feet. A section of exposed rock known to local riders as "mini-Moab" provides some fun riding, too. It's pretty easy to put together a 10-15 mile ride without repeating yourself much.
How to get there:
From CA60/I-215 Take Cantral Avenue exit down the hill, and one trailhead is on the left just after Lochmoor. Others are available off of Canyon Crest, Alessandro, and Via Mindi.
Our group rides this trail frequently. Check out www.teamdirtywork.com for upcoming rides.