Originally Posted by HerrKaLeun

Natural air loss should be minimal, not something you need to make up daily or weekly. Variations with temperature should cancel out on average. and within one week you likely don't have 50°F swings for that to matter. And assuming all your bikes are in the same temperature, there must be something wrong with the tube/valve. Unless you for some reason take the wheel out and store it in the freezer ....

How did you check for leaks? I say that because I had a slow leak in my rear tire and couldn't tell by "listening" or "looking". It is just i filled it to 55 psi and at the end of a ride the next day i could feel it getting empty and measured at home 30 psi only. I filled the sink with water and the pressurized tube in and saw the tiny air bubbles. You have to do that slowly because the outside of the tube also retains some micro-bubbles of air at first. The valve also could be the problem. Most Presta valves don't have replaceable cores, so you may need to replace the tube.