Nice, but you're supposed to use an old EF Schwinn as a klunker! I've been considering building up a road bike for the same purpose you have. As Gene says, sounds like fun!

Check out some of these Jobst Brandt photos on some trails in California with a road bike and 25c tires: http://www.bayareabikehub.com/rides/past_rides.htm

(Unfortunately, it looks like as the result of a transfer to a new server, the slideshows are now inoperable. They had some great photos.)