MLH from Overland Park KS on 3/12/2006 8:54:06 AM:
I definitely don't qualify as a professional on the subject but based on several combinations that I have tried and observing what others are using on the trail, it seems that 700 X 32-37mm tires offer the best combination of relative puncture resistance, low rolling resistance and comfort. Most road bikes don't have clearance for tires over 28mm, which is problematic if the trail is wet and/or soft or if you are carrying extra weight such as bags etc. Thus the bike choice would be a touring, cyclocross, and most hybrids. I have emailed you an article regarding specific tire choices.