I've been going off that chart for a long time. With my bike I weigh @180. I go with 70 front and 110 rear, sometimes a tad less. My main ride is the aluminum Focus with 23c's, most of my roads are chipseal and it's smooth enough for me. And it's funny, the last time I ever had a pinch flat was back when I would jack the pressure up to 120 front and rear. Used to get them all the time at those pressures.