There is no reason for you to need 145psi to avoid pinch flats. You might be at risk of blowing the tire off the rim from pressure alone. I'm 250 and I run 115-120 rear/105-110 front with 23mm Michelins on Ksyriums. I also went with 24f/28r spoked Zipps. I have only flatted once in the last 2 years and that was definitely a road object. I would have gone with more spokes and wider tires but you'll probably be okay depending how you ride. Probably just isn't a word that instills confidence bombing down a hill at 45mph.