Reddit reviews Mountain Biking Orange County California

Anything in the Santa Ana Mountains or (a little further form you) Laguna, there will be trails! Just look for green on Google maps, zoom in and see if there is a trail. I mentioned Black Star Canyon which is a really good one. but I'm sure you can find more. I know road trails a lot better, so I can't remember names of specific MTB trails. I'd probably look at Oneill regional park, Whiting Ranch Wilderness Park, Anything coming off Alta Laguna Park will be stupid fun, I've always wanted to do the Westridge Trail, but never have. There are good books on this type of thing too, here is one

Lots of trails in south orange county. I finally bought a book on the subject (I'll post the name of it when I get home). I ride Tijeras/Trabuco loop quite a bit. But I've also ridden Bellview Trail (by Coto). There is lots of trails in and around Saddleback mountain. I'm a poor climber so I stay away from those. I hear Whiting Ranch is a good trail. Theres trails in Laguna Niguel and Crystal Cove.

Have you tried the socaltrailriders website?

EDIT: Here's the book.