Last ride, I inflated my tires to 8psi in front, and not much in the back.
When I got home, I had a "flat" front tire. The same kind of stuff had already happened, so, I put it to the test at 25psi(actually maybe a little less...1.5 bar). I even rode for 2 hours with the tire so inflated. I checked them when I got home. Guess what? They didn't loose any air!

How the heck is this possible? they can't keep 8psi, and endure a 2hour 25psi ride.

Any one can explain this, or should I call Scully and Mulder?

 

It is possiable that the 25psi may have closed any opening that the 8psi was not tight enough to do. Example: you have some grass between your wheel and tire, the 8 may not press the tire hard enough against the rim to seal the gap, but the 25 put enough pressure on it to close it.

Just my opinion.

 

Happens with me in the dunes sand will get in between the tire and the wheel. I end up with a slow air leak. I have to clean it out once or twice a year. You can check it with some soapy water just lay the tire on it side and add a little soapy water and look for bubbles.

 

This happens when I run my big tires. The air leaks around the rim.