Originally Posted by
veganbikes
I check my tires regularly but with my Schwalbe Super Moto-Xs 650bx2.4 I am probably pumping once a month and not because I am letting them run deflated but they lose very little PSI with pretty standard inner tubes and I have a separate Topeak gauge and one on the pump. Thicker sidewalls and treads tend to lead to less air being able to escape. I am usually at 40-45psi as Hank Hill would say "firm with just a little give"
With bike tires and a standard tubed setup, I doubt the thickness or tire sidewalls and treads have anything to do with the rate of air loss. Tires are more porous than tubes. In this case, the rate of loss has most to do with tire volume and amount of initial pressure. In your example above, once a month is sufficient unless you run latex or ultra-light butyl tubes which lose air more quickly.
FWIW, I run thorn resistant tubes in my mountain bikes and it takes a few months for the pressure to drop to where I have to re-inflate.