I give them a "pinch-test" before every ride . If I'm riding every day, I pump up probably every other ride, maybe every 3rd if some of the rides are very short (under 25 miles). If the bike is sitting around longer between rides, I might have to pump up every ride. I pump to 120 front and rear. I think my tires are rated to 145 but I've never tried riding them at such high pressure (not to mention that I'm not sure I'm strong enough to pump that much air into the tire).