I just purchased a tire floor pump with a gauge for my bike. The gauge seems to start off at 0 PSI when I connect the pump to the tire. So, do I need to use a separate tire gauge to first measure the current pressure of my tires prior to using the pump so as not to over-inflate them?
Additional info: I purchased the Serfas TCPG Bicycle Floor Pump and the gauge does not move at all when the hose is attached until I start pumping. Not sure if that's correct or if I'm doing something wrong.