After searching the forums and elsewhere I couldn't find a solid answer...
The subject: a year 2000 Gary Fisher Wahoo hybrid, stock. Pic here. Has both road tires and trail tires.
The rider: Lives in Marin County, birthplace of US mountain biking. Tons of road and commuting experience and plenty of fairly chill trail riding experience. No experience doing super-hilly/rocky fire roads or worse.
The issue: I own a road bike and adore it, but I want to look for an alternative to get away from the traffic-filled roads. I live at the base of Big Rock Ridge, for those NorCalers around...I want to start biking where I've been trailrunning, and even start on some of the basic trails of Mt. Tamalpais itself.
The challenge: Despite seeing a lot of people converting hybrids to road bikes, I want to go the other way...I'd like to outfit this steel-framed, Altus-equipped hybrid for XC and all-mountain style riding (at least by these definitions).
The question: What pitfalls lie in the way of this plan? Could I put a low-travel suspension fork on the hybrid and just give it a shot - or is that even necessary? If I stick with dry-conditions biking, could I get by with standard stock brakes instead of upgrading to discs? Will I run afoul of inappropriate frame geometry? Is all this so silly that I should sell the stupid hybrid and get an AM/XC bike (loathe to do so, as it makes a great utility bike)?
Thoughts, crew? I'd love to get your thoughts, as I definitely don't trust the local LBS's to do anything but try to sell me a fresh new bike even if I don't need one...