Now that its actually winter where I live I have a question about tire pressure and cold weather. I store my bikes indoors. Going from room temp to -30C or colder is a big change in temp. I am curious if there is a way to figure out how much psi I will lose based on temp. For example if at room temp I am at 35psi how much pressure will I lose at -30C. Or could someone point me toward a formula?