What you're probably seeing is the difference between cold pressure and warm pressure. As you probably know, any tire pressure spec (cars, bikes, etc) is based on cold pressure. This is to make that pressure reading fairly uniform. Because, as as soon as you start driving or riding, the tire temperature - and therefore the pressure - will go up. Friction from the road, heat from the road, braking, air temp, etc. I'd be surprised if the pressure of your tire didn't go up with use. I've never checked a bike, but I do know that the pressure of my travel trailer tires goes up substantially as soon as I start towing (the pressure monitoring system also measures temperature)
An interesting question to me would be - after you ride, and the tire has cooled to the temperature at which you took the original pressure, what is it?
Last edited by Camilo; 05-30-22 at 01:06 PM.