i'm 165lbs for evah and run like 105-110 on pavement depending if wet or dry.
rides with a ton o dirt like if i'm riding round mt washington and hit up the jefferson notch road (highest maintained road in the state dirt/gravelly, can be quite loose, and pinkham b road, i'll run like 100. i have gone as low as 95, but 100 is magic/safe so it seems.
i run maxxis re-fuse 700x25 which are smaller in size than say most bontrager's or conti's.
brilliant tire with amazing grip pattern for cruizing singletrack/dirt roads.
if you are light you can go lower.
rog