Anybody else out there finding it difficult to find the correct amount of air/nitrogen to inflate their tires?

I have the original 8" & 9" Pirelli Zero's, and with both air and Nitrogen, when I inflate with the recommended 36 PSI after running for about 15 minutes, depending on how cold or hot I'm getting a fluctuation in pressure from 32-40 PSI.

HELP!

tom

 

Pressure variations with temperature are normal and expected. You'll get best results if you set your tires to your target pressure when they are at typical operating temperature for current weather conditions.

 

I thought you were supposed to set your tire pressure when the tires were cold.