If you would like to explore going "off the beaten path" (read: Mountain or trail biking), you could also post your itinerary on our forum http://www.pinoymtbiker.org/forum/. Just introduce yourself and what you intend to do. I am sure a lot of groups and bikers would either join you for certain legs of your trip or might join you for the whole trip. A team of two mountain bikers just finished a trip from Manila to as far as Davao just the other day. I am sure they can give you fresh and updated tips on what to do and what to avoid in such a trip. Ride safe!